Chapter 25 - Phylogeny
Phylogenies are Based on Common Ancestries
1. Phylogeny is defined as the evolutionary history of a group of organisms. Systematics is a method used by scientist to reconstruct phylogeny. Systematics uses an analytical approach to understand the diversity and relationships of living and extinct organisms.
2. The process of sedimentation involves is the formation of sedimentary rocks, formed from sand and mud settling to the bottoms of seas, lakes, and marshes. Newer layers of sediment cover older ones, with each layer formed becoming a new strata. Fossils appear in the sedimentary strata and can be used to construct phylogenies if the ages can be determined. The portions of organisms that are most likely to fossilize are shells, skeletons, leaves, and branches.
3. It is important to distinguish between homology and analogy before selecting characters to use in the construction of phylogenies because analogies do not necessarily mean that the two organisms had a similar ancestor. Homology is the similarity in characteristics resulting from a similar ancestry, while analogy is the similarity between two species due to convergent evolution and not from a common ancestor. Consider the example and explanation that follows in number four.
4. Bats and many species of birds both have wings that are used to fly. However, a bat’s wing is more closely related to a mammalian forelimb than that of a bird’s. The bat’s wing is therefore homologous to vertebrate forelimbs (and birds are vertebrates), and analogous to a bird’s wing (due to specificity of function).
5. Molecular systematics is the comparison of nucleic acids (genome) or other molecules in different species to infer relatedness. A problem systematists may encounter in carrying out molecular comparison of nucleic acids is that the findings are sometimes inconclusive, like in some cases of taxa which diverged at almost the same time.
6. The Linnaean system uses binomial nomenclature to assign every species with a two-part Latinized name. The first part is the specie’s genus, which is the closest group that the specie belongs to. The second part is the specific epithet. It refers to one species within each genus. The first letter of the genus is capitalized. Hierarchal classification is also used in the Linnaean system to group species into increasingly broader taxonomic categories. Species that appear to be closely related to each other are grouped in the same genus. Genera (plural of “genus”) are grouped into progressively broader categories: family, order, class, phylum, kingdom, and domain. Each of these taxonomic levels is more comprehensive than the previous one. The named taxonomic unit at any level is known as the taxon.
7. Taxonomic levels, from most broad to most restrictive = Domain, kingdom, phylum, class, order, family, genus, species
8. A clade is a group of species which includes the ancestral and descendent species. Valid monophyletic clades are ones that consists of the ancestral specie and all their descendants. Paraphyletic clades are missing information for certain of its members (some but not all descendants). Polyphyletic clades lack a common ancestor.
9. Homologous features or characters (features possessed by particular taxons) must be separated as shared derived characters or shared primitive characters. A shared derived character is unique to a particular clade. A shared primitive character is found not only in the clade being analyzed, but also in older clades. Shared derived characters are useful in establishing a phylogeny, but shared primitive characters are not.
10. Shared derived characters are useful in establishing a phylogeny. After distinguishing derived from primitive characters using outgroup comparison/analysis, a cladogram can be created with the chronological sequence of branching during the evolutionary history of a set of organisms. However, the chronology charted gives no indication of the relative (earliest/latest) or absolute (years) time of the species’ origin. Phylogenetic trees show relative branching patterns (earlier and later as opposed to a given number of years). More information is needed to convert a cladogram into such a diagram. Fossil records may be used as indicators of when characters first appeared, and in what groups.
11. The level at which an analysis is being performed will determine the status of a character as shared derived or shared primitive. Outgroup comparison is used to differentiate between the two, and is an important step in cladistic analysis. First, however, the outgroup—the species or group of closely related species to the species being studied–must be identified. Then, the ingroup, which displays a mixture of shared primitive and shared derived characters, must be indentified. The analysis replies on the assumption that any shared homologies between the two groups are primitive characters. Homologies present in some or all of the ingroup are assumed to be derived after divergence between the two groups.
13. Different types of diagrams of the chronological sequence of branching during the evolutionary history of a set of organisms exist. Each provides different information regarding timing. In phylograms, branch lengths reflect how many genetic changes have occurred in a certain DNA or RNA sequence of a lineage. But while branches of a phylogram may differ in length, all the lineages descended from a common ancestor and have survived for the same number of years. These equal amount of chronological time are represented in an ultrameric tree. Ultrameric trees have branching patterns similar to phylograms, except that all the branches traceable from the common ancestor to the present are of equal lengths. They do not contain information concerning different evolutionary rates as phylograms do. However, they do draw data from the fossil record in order to place certain branch points in the context of geological time.
15. A phylogenetic tree represents a hypothesis about how the organisms in the tree are related. The best hypothesis is the one that best fits all the data. Hypotheses made may be rejected or edited due to revisions made to the trees (which must be made due to new molecular methods for species comparison and the tracing of phylogeny). The strongest hypothesis is supported by a multitude of molecular, morphological, and fossil evidence
Unless there is evidence to prove else wise, the assumption generally is that the simplest tree is the most likely to have occurred in nature. This however, is not always the case. Consider the evolution of the four-chambered heart, which is different in birds and mammals, proving that such a trait is analogous, not homologous.
16. There are two types of homologous genes: orthologous and paralogous. Orthologous genes are ones found in different gene pools due to speciation, for example the ß hemoglobin genes found in both humans and mice. Orthologous genes are widespread, extending of enormous evolutionary distances, since all living things share certain biochemical and developmental pathways. Paralogous genes are ones that result from gene duplication and are found in more than one copy in the same genome (i.e. olfactory receptor genes). Gene duplications may leads to families of paralogous genes.
*It is important to note, however, that gene number does not seem to increase at the same rate as phenotypic complexity. Consider humans, who have only five times as many genes as yeast, which is a simple unicellular eukaryote, yet humans have large, complex brains and body with more than 200 different types of tissues.
17. Molecular clocks are used to determine the appropriate time of key evolutionary events, and are based upon the observation that certain genome regions evolve at constant rates. For orthologous genes, the number of nucleotide substitutions in these areas is proportional to the time that has elapsed since the two species last shared a common ancestor. For paralogous genes, the number of substitutions is proportional to the time since the genes became duplicated. Molecular clocks are calibrated by graphing nucleotide differences against the timing of a series of evolutionary branch points derived from the fossil record. The slope of the line of best fit represents the molecular clock’s evolutionary rate, which can be used to estimate the absolute date of evolutionary events that have no fossil record.
18. Molecular clocks do have limitations, however, as none are completely accurate. Generally smooth average rates of change make genes good for molecular clocks, but no genes are precise enough to accurately mark the rate of base change: there are almost always chance deviations. Genes vary significantly in rates of change; certain ones evolve faster than others. The molecular clock assumes that DNA sequence changes are caused by genetic drift and are selectively neutral. This neutral theory suggests that much evolutionary change in genes and proteins has no effect on fitness and is unaffected by Darwinian selection; consequentially, the rate of molecular change should be clocklike in regularity. However, certain DNA changes are favored by natural selection. This means that the accuracy and utility of molecular clocks for timing evolution is questionable. Estimates provided by these clocks are highly uncertain.
Thursday, January 10, 2008
AP Biology Ch24 Objectives
Chapter 24 – The Origin of Species
What Is a Species?
1. There are two patterns of speciation confirmed by the fossil record: anagenesis and cladogenesis. The former, anagenesis, can be defined as phyletic evolution, or the accumulation of changes associated with one species’ gradual transformation into another species. The latter, cladogenesis, is branching evolution, the budding of one or more new species from a parent species. Cladogenesis promotes biological diversity, unlike anagenesis, because it increases the number of a species.
2. The biological species concept proposed by Ernst Mayr defined a species as a population or group of populations with members who have the potential to breed with one another in nature, and produce viable, fertile offspring. These same members should not be able to produce such offspring with members of other species. Species are thus the largest grouping of individuals able to exchange genetic material while remaining genetically isolated from others. Physically similarity is not an issue.
3. Reproductive barriers can be categorized as prezygotic or postzygotic, depending on when they function. Prezygotic barriers impede mating between species or hinder fertilization of ova if members of different species attempt to mate. Should sperm from one species fertilize the ovum of another, postzygotic barriers—including reduced hybrid viability, reduced hybrid fertility, and hybrid breakdown—will prevent the development of a viable, fertile adult from the hybrid zygote. These barriers include.
4. There are five prezygotic isolating mechanisms: habitat isolation, behavioral isolation, temporal isolation, mechanical isolation, and gametic isolation.
Habitat isolation occurs when organisms in the same geographic area use different habitats, which lower their encounters with each other (and consequentially stop them from mating). Case and point: garter snakes in the same region may not mate because one is terrestrial while the other lives in water.
Behavioral isolation involves elaborate courtship behaviors unique to certain species. These complex displays—for example the blue-footed male booby’s dance--attract mates.
Temporal isolation is when species breed during different seasons, years, or times of day. These limits/restrictions prevent the western spotted skunk from mating with the eastern species because the former mates during the end of summer, while the latter mates near the end of winter.
Mechanical isolation deals with anatomic incompatibility. Closely related species may attempt to mate, but transfer of gametes will not be possible. This is evident with flowering plants, pollinated by insects or other animals. Many of the insects do not have male and female copulatory organs that fit together.
Gametic isolation occurs when the gametes of two species cannot form a zygote. Incompatibilities between the two prevent fertilization. The female reproductive tract may not allow the sperm to survive, or the egg coat may not be recognized by sperm. Flowers discriminate between pollen of different species using that molecular recognition mechanism.
5. Reduced hybrid viability can be caused by genetic incompatibility between the two species.
6. Hybrid breakdown maintain separate species even if fertilization occurs by preventing the first generation from producing viable, fertile offspring. This means that the second generation will have a relative fitness of zero and no more offspring can be produced.
7. The biological species concept has limitation when applies to nature. First of all, fossils cannot be tested for reproductive isolation and thus the former creatures cannot be properly separated into species. Secondly, information on interbreeding is lacking, even for living species. Lastly, this concept cannot be applied to asexually reproducing organisms.
8. The ecological species concept defines a species in terms of its ecological niche, its role in the biological community, and the environmental resources it uses. This definition accommodates both asexually and sexually reproducing organisms.
The paleontological species concept focuses on morphologically discrete species known only from the fossil record. Because little is known about the mating capability of fossil species, the biological species concept is not useful for them.
The phylogenetic species concept defines a species as a set of organisms with a unique genetic history. Physical characteristics and molecular sequences of organisms are compared to determine speciation. When sibling species are found—ones that are so alike that they can’t be distinguished on morphological ground—the biological species concept is applied to determine if the phylogenetic distinction is confirmed by reproductive incompatibility.
The oldest and still most practical, the morphological species concept, defines a species by a unique set of structural features. Applicable to asexual and sexual species, it can be used without information about gene flow. However, this concept is also subjective.
9. Allopatric speciation is the restriction of gene flow due to geographic separation. This separation can lead to the origin of species from a division of one population into isolated groups. Allopatric speciation depends very much upon the ability of the organisms to move about (and thus reproduce). Allopatric speciation is when a new species evolves due to the particular geography. The process occurs because of geographic separation.
Sympatric speciation reduces gene flow in geographically overlapping populations through biological factors, such as chromosomal changes and nonrandom mating. Sympatric speciation is when a new species evolves in spite of sharing their geographic area.
10. The allopatric speciation model stipulates that geological processes—for example mountain ranges, land bridges or lakes—can fragment a population into two or more isolated populations. Alternatively, certain individuals may colonize a new, geographically remote area and become isolated from their parent population. Geographical barriers need only be significant enough to prevent organisms from moving around and mating. Thus separation is established and gene pools begin to diverge through mutations, sexual selection, genetic drift, and/or environmental selective pressures.
11. When new environmental opportunities rise, the evolution of numerous many adapted species from one common ancestor is triggered. This process, called adaptive radiation, can occur either when a few organisms colonize a new area, or when extinction opens up an ecological niche for survivors. Examples of this type of evolution have been found in the Galápagos and Hawaiian archipelagoes.
When the Hawaiian archipelago was formed 3,500 km from the nearest continent by hardened volcanic lava, stray organisms came to the islands by wind or ocean currents. The physicially diverse islands have had multiple invasions, and allopatric and sympatric speciation events have ignited an explosion of adaptive radiation of novel species. Small populations of stray plants and animals from the South American mainland also colonized the Galápagos Islands and gave rise to the species that now inhabit the islands. The speciation is evident when looking at the females of the Galápagos ground finch Geospiza difficilis. These organisms respond to the songs of males from the same island but ignore the songs of males of the same species from other islands.
12. Reproductive barrier must evolve between sympatric populations to prevent them from mating. If they mated, they would be considered to be of the same species. In plants, accidents during during cell division can create the barrier by producing an extra sets of chromosomes--a mutant condition known as polyploidy. In animals, barriers may result from gene-based shifts in habitat or mate preference. Reproductive isolation can also result when genetic factors cause individuals to exploit resources not used by their parents.
[UNFINISHED... need to "Describe examples of the evolution of prezygotic barriers and the evolution of postzygotic barriers"]
13. Sympatric speciation is the origination of a new species in the geographic area of its parent species. Reproductive barriers evolve between the two populations to prevent interbreeding. Polyploidy can cause reproductive isolation because the hybrids are fertile when copulating with one another, but are unable to breed with their parents. They represent a new biological species due to the prezygotic barriers that prevent them from reproducing with others.
14. Autopolyploid species have more than two chromosome sets, all derived from a single species. For example, a failure of mitosis or meiosis can double a cell’s chromosome number from diploid to tetraploid. The tetraploid can then reproduce with itself or with other tetraploids. It cannot mate with diploids from the original population, because of abnormal meiosis by the triploid hybrid offspring. Allypolyploidy species are ones produced by the mating of two different species, and is a more common method of producing polyploid individuals. While the hybrids are usually sterile, they may be quite vigorous and propagate asexually. One example of allypolyploidy animals is a mule, an offspring of a donkey and a horse.
15. Cichlid fished may have speciated in sympatry in Lake Victoria because they will not mate under normal light since females have specific color preferences and males differ in color. However, under light conditions that de-emphasize color differences, females will mate with males of the other species and produce viable, fertile offspring. Genetic drift resulted in chance differences in the genetic makeup of the subpopulations, with different male colors and female preferences. The lack of postzygotic barriers in this case suggests that speciation occurred relatively recently.
16. Adaptive radiation is evolution of many diversely adapted species from a common ancestor when new environmental opportunities arise. It occurs when a few organisms make their way into new areas or when extinction opens up ecological niches for the survivors. For example, A major adaptive radiation of mammals followed the extinction of the dinosaurs 65 million years ago.
17. In the speciation of mimulus, one locus implicated influences flower color; the other affects the amount of nectar flowers produce. By determining attractiveness of the flowers to different pollinators, allelic diversity at these loci has led to speciation.
From Speciation to Macroevolution
18. A complex structure can evolve by natural selection by having a single evolutionary organ. They evolve by incremental adaptation of smaller parts that benefited their owners at each stage.
19. Exaptation structures that evolve in one context, but become co-opted for another function. An example of an exaptation is the changing function of lightweight, honeycombed bones of birds. The fossil record indicates that light bones predated flight. Therefore, they must have had some function on the ground. Once flight became an advantage, natural selection would have remodeled the skeleton to better fit their additional function. The wing-like forelimbs and feathers that increased the surface area of these forelimbs were co-opted for flight after functioning in some other capacity.
20. Slight genetic divergences may lead to major morphological differences between species in part by genes that program development by controlling the rate, timing, and spatial pattern of changes in form as an organism develops from a zygote to an adult. If you change relative rates of growth even slightly, you can change the adult form substantially.
21. The evolution of changes in temporal and spatial developmental dynamics can result in evolutionary novelties by [UNFINISHED]
22. Evo-devo is a field of interdisciplinary research that examines how slight genetic divergences can become magnified into major morphological differences between species.
Heterochrony is an evolutionary change in the rate or timing of developmental events, which has led to many striking evolutionary transformations.
Allometric growth tracks how proportions of structures change due to different growth rates during development.
Paedomorphosis occurs when the rate of reproductive development accelerates compared to somatic development. A sexually mature stage can then retain juvenile structures.
23. Extracting a single evolutionary progression from a fossil record can be misleading because many species appear as new forms rather suddenly (in geologic terms), persist essentially unchanged, and then disappear from the fossil record. Also, all species continue to adapt after they arise, but often by changes that do not leave a fossil record, such as small biochemical modifications. Therefore, one must look in both directions from a single evolutionary progression to learn more about the one in question.
24. Species selection means that as individual organisms undergo natural selection, species undergo a similar process. The species that endure the longest and generate the greatest number of new species determine the direction of major evolutionary trends.
25. Evolutionary change is not goal-directed because the fossil record shows apparent evolutionary trends. Evolution is a response to interactions between organisms and their current environments, leading to changes in evolutionary trends as conditions change.
What Is a Species?
1. There are two patterns of speciation confirmed by the fossil record: anagenesis and cladogenesis. The former, anagenesis, can be defined as phyletic evolution, or the accumulation of changes associated with one species’ gradual transformation into another species. The latter, cladogenesis, is branching evolution, the budding of one or more new species from a parent species. Cladogenesis promotes biological diversity, unlike anagenesis, because it increases the number of a species.
2. The biological species concept proposed by Ernst Mayr defined a species as a population or group of populations with members who have the potential to breed with one another in nature, and produce viable, fertile offspring. These same members should not be able to produce such offspring with members of other species. Species are thus the largest grouping of individuals able to exchange genetic material while remaining genetically isolated from others. Physically similarity is not an issue.
3. Reproductive barriers can be categorized as prezygotic or postzygotic, depending on when they function. Prezygotic barriers impede mating between species or hinder fertilization of ova if members of different species attempt to mate. Should sperm from one species fertilize the ovum of another, postzygotic barriers—including reduced hybrid viability, reduced hybrid fertility, and hybrid breakdown—will prevent the development of a viable, fertile adult from the hybrid zygote. These barriers include.
4. There are five prezygotic isolating mechanisms: habitat isolation, behavioral isolation, temporal isolation, mechanical isolation, and gametic isolation.
Habitat isolation occurs when organisms in the same geographic area use different habitats, which lower their encounters with each other (and consequentially stop them from mating). Case and point: garter snakes in the same region may not mate because one is terrestrial while the other lives in water.
Behavioral isolation involves elaborate courtship behaviors unique to certain species. These complex displays—for example the blue-footed male booby’s dance--attract mates.
Temporal isolation is when species breed during different seasons, years, or times of day. These limits/restrictions prevent the western spotted skunk from mating with the eastern species because the former mates during the end of summer, while the latter mates near the end of winter.
Mechanical isolation deals with anatomic incompatibility. Closely related species may attempt to mate, but transfer of gametes will not be possible. This is evident with flowering plants, pollinated by insects or other animals. Many of the insects do not have male and female copulatory organs that fit together.
Gametic isolation occurs when the gametes of two species cannot form a zygote. Incompatibilities between the two prevent fertilization. The female reproductive tract may not allow the sperm to survive, or the egg coat may not be recognized by sperm. Flowers discriminate between pollen of different species using that molecular recognition mechanism.
5. Reduced hybrid viability can be caused by genetic incompatibility between the two species.
6. Hybrid breakdown maintain separate species even if fertilization occurs by preventing the first generation from producing viable, fertile offspring. This means that the second generation will have a relative fitness of zero and no more offspring can be produced.
7. The biological species concept has limitation when applies to nature. First of all, fossils cannot be tested for reproductive isolation and thus the former creatures cannot be properly separated into species. Secondly, information on interbreeding is lacking, even for living species. Lastly, this concept cannot be applied to asexually reproducing organisms.
8. The ecological species concept defines a species in terms of its ecological niche, its role in the biological community, and the environmental resources it uses. This definition accommodates both asexually and sexually reproducing organisms.
The paleontological species concept focuses on morphologically discrete species known only from the fossil record. Because little is known about the mating capability of fossil species, the biological species concept is not useful for them.
The phylogenetic species concept defines a species as a set of organisms with a unique genetic history. Physical characteristics and molecular sequences of organisms are compared to determine speciation. When sibling species are found—ones that are so alike that they can’t be distinguished on morphological ground—the biological species concept is applied to determine if the phylogenetic distinction is confirmed by reproductive incompatibility.
The oldest and still most practical, the morphological species concept, defines a species by a unique set of structural features. Applicable to asexual and sexual species, it can be used without information about gene flow. However, this concept is also subjective.
9. Allopatric speciation is the restriction of gene flow due to geographic separation. This separation can lead to the origin of species from a division of one population into isolated groups. Allopatric speciation depends very much upon the ability of the organisms to move about (and thus reproduce). Allopatric speciation is when a new species evolves due to the particular geography. The process occurs because of geographic separation.
Sympatric speciation reduces gene flow in geographically overlapping populations through biological factors, such as chromosomal changes and nonrandom mating. Sympatric speciation is when a new species evolves in spite of sharing their geographic area.
10. The allopatric speciation model stipulates that geological processes—for example mountain ranges, land bridges or lakes—can fragment a population into two or more isolated populations. Alternatively, certain individuals may colonize a new, geographically remote area and become isolated from their parent population. Geographical barriers need only be significant enough to prevent organisms from moving around and mating. Thus separation is established and gene pools begin to diverge through mutations, sexual selection, genetic drift, and/or environmental selective pressures.
11. When new environmental opportunities rise, the evolution of numerous many adapted species from one common ancestor is triggered. This process, called adaptive radiation, can occur either when a few organisms colonize a new area, or when extinction opens up an ecological niche for survivors. Examples of this type of evolution have been found in the Galápagos and Hawaiian archipelagoes.
When the Hawaiian archipelago was formed 3,500 km from the nearest continent by hardened volcanic lava, stray organisms came to the islands by wind or ocean currents. The physicially diverse islands have had multiple invasions, and allopatric and sympatric speciation events have ignited an explosion of adaptive radiation of novel species. Small populations of stray plants and animals from the South American mainland also colonized the Galápagos Islands and gave rise to the species that now inhabit the islands. The speciation is evident when looking at the females of the Galápagos ground finch Geospiza difficilis. These organisms respond to the songs of males from the same island but ignore the songs of males of the same species from other islands.
12. Reproductive barrier must evolve between sympatric populations to prevent them from mating. If they mated, they would be considered to be of the same species. In plants, accidents during during cell division can create the barrier by producing an extra sets of chromosomes--a mutant condition known as polyploidy. In animals, barriers may result from gene-based shifts in habitat or mate preference. Reproductive isolation can also result when genetic factors cause individuals to exploit resources not used by their parents.
[UNFINISHED... need to "Describe examples of the evolution of prezygotic barriers and the evolution of postzygotic barriers"]
13. Sympatric speciation is the origination of a new species in the geographic area of its parent species. Reproductive barriers evolve between the two populations to prevent interbreeding. Polyploidy can cause reproductive isolation because the hybrids are fertile when copulating with one another, but are unable to breed with their parents. They represent a new biological species due to the prezygotic barriers that prevent them from reproducing with others.
14. Autopolyploid species have more than two chromosome sets, all derived from a single species. For example, a failure of mitosis or meiosis can double a cell’s chromosome number from diploid to tetraploid. The tetraploid can then reproduce with itself or with other tetraploids. It cannot mate with diploids from the original population, because of abnormal meiosis by the triploid hybrid offspring. Allypolyploidy species are ones produced by the mating of two different species, and is a more common method of producing polyploid individuals. While the hybrids are usually sterile, they may be quite vigorous and propagate asexually. One example of allypolyploidy animals is a mule, an offspring of a donkey and a horse.
15. Cichlid fished may have speciated in sympatry in Lake Victoria because they will not mate under normal light since females have specific color preferences and males differ in color. However, under light conditions that de-emphasize color differences, females will mate with males of the other species and produce viable, fertile offspring. Genetic drift resulted in chance differences in the genetic makeup of the subpopulations, with different male colors and female preferences. The lack of postzygotic barriers in this case suggests that speciation occurred relatively recently.
16. Adaptive radiation is evolution of many diversely adapted species from a common ancestor when new environmental opportunities arise. It occurs when a few organisms make their way into new areas or when extinction opens up ecological niches for the survivors. For example, A major adaptive radiation of mammals followed the extinction of the dinosaurs 65 million years ago.
17. In the speciation of mimulus, one locus implicated influences flower color; the other affects the amount of nectar flowers produce. By determining attractiveness of the flowers to different pollinators, allelic diversity at these loci has led to speciation.
From Speciation to Macroevolution
18. A complex structure can evolve by natural selection by having a single evolutionary organ. They evolve by incremental adaptation of smaller parts that benefited their owners at each stage.
19. Exaptation structures that evolve in one context, but become co-opted for another function. An example of an exaptation is the changing function of lightweight, honeycombed bones of birds. The fossil record indicates that light bones predated flight. Therefore, they must have had some function on the ground. Once flight became an advantage, natural selection would have remodeled the skeleton to better fit their additional function. The wing-like forelimbs and feathers that increased the surface area of these forelimbs were co-opted for flight after functioning in some other capacity.
20. Slight genetic divergences may lead to major morphological differences between species in part by genes that program development by controlling the rate, timing, and spatial pattern of changes in form as an organism develops from a zygote to an adult. If you change relative rates of growth even slightly, you can change the adult form substantially.
21. The evolution of changes in temporal and spatial developmental dynamics can result in evolutionary novelties by [UNFINISHED]
22. Evo-devo is a field of interdisciplinary research that examines how slight genetic divergences can become magnified into major morphological differences between species.
Heterochrony is an evolutionary change in the rate or timing of developmental events, which has led to many striking evolutionary transformations.
Allometric growth tracks how proportions of structures change due to different growth rates during development.
Paedomorphosis occurs when the rate of reproductive development accelerates compared to somatic development. A sexually mature stage can then retain juvenile structures.
23. Extracting a single evolutionary progression from a fossil record can be misleading because many species appear as new forms rather suddenly (in geologic terms), persist essentially unchanged, and then disappear from the fossil record. Also, all species continue to adapt after they arise, but often by changes that do not leave a fossil record, such as small biochemical modifications. Therefore, one must look in both directions from a single evolutionary progression to learn more about the one in question.
24. Species selection means that as individual organisms undergo natural selection, species undergo a similar process. The species that endure the longest and generate the greatest number of new species determine the direction of major evolutionary trends.
25. Evolutionary change is not goal-directed because the fossil record shows apparent evolutionary trends. Evolution is a response to interactions between organisms and their current environments, leading to changes in evolutionary trends as conditions change.
AP Biology Ch23 Objectives
Chapter 23 – The Evolution of Populations
Population Genetics
1. The statement, “It is the population, not the individual, that evolves” means that while the impact of evolution can be seen in an organism, evolution is defined as the changes in a population over time. The impact of natural selection is apparent only in the relative reproductive success of individuals based on their combinations of inherited traits.
2. Darwin’s explanation needed support that to explain how chance variation arise in a population, and how variations are passed down from parents to offspring. At the time that Darwin introduced his theory, the belief was that parents passed down a blend of their traits to their offspring. Over time, this process would eliminate differences between individuals. Mendel’s particulate hypothesis of inheritance support Darwin’s theory of evolution by natural selection because it stated that parents pass on discrete heritable units (today we call them genes), which retain their identities in offspring.
3. Discrete heritable traits are referred to as genes today. These units retain their identities in offspring. Discrete traits are influenced by a single loci. They are “either-or.” Quantitative traits vary along a continuum. Their characters are influenced by multiple loci. Quantitative traits have a genetic basis, and the alleles at each of the multiple loci follow the Mendelian laws of inheritance
4. The “modern synthesis” is a comprehensive theory of evolution, which came about in the 1940s. Integrating paleontology, taxonomy, biogeography, and population genetics, it emphasizes three mains things:
The unit of evolution is a population
Natural selection has a central role as the most important mechanism of adaptive evolution
Large changes can evolve from an accumulation of small changes over long periods of times (gradualism)
5. A contained group of individuals belonging to the same species is defined as a population. A species is a group of individuals who are able to interbreed and produce viable, fertile offspring. A population’s gene pool is its complete collection of genes at any given time. A gene pool is made of all the alleles at all the gene loci in all the population’s individuals.
6. Meiosis and random fertilization alone will not alter the frequency of alleles or genotypes in a population because [UNFINISHED]
7. For a population to remain in the Hardy-Weinberg equilibrium five conditions must be met, being:
The population size is extremely large (small populations have genetic drift)
Random mating must occur (if individuals pick mates with certain genotypes or inbreeding offcurs, gametes will not mix randomly)
There is no gene flow, or transfer of alleles (which can change the allele proportion)
There are no mutations (any gene modification, introduction, or loss will alter the gene pool)
There is no natural selection (differential survival/reproductive success will alter genotype frequencies)
8. The Hardy Weinberg equation is as follows: p2 + 2pq + q2 = 1.0
When the frequency of homozygous recessive individuals in a population is 25%, the allele frequencies would be:
q-squared = .25 --> q = .5
p = .5
Mutation and Sexual Recombination
9. The majority of point mutations, which are changes in a single base of a gene, are harmless because most eukaryotic genomes don’t code for protein products. Also, because the genetic code is redundant, so point mutations may not have any affect.
10. Mutations have little quantitative effect on allele frequencies in a large population because most occur in somatic cells and thus disappear when the organism dies. The few mutations in cell lines that form gametes are passed to offspring, but only a fraction of them spread and become fixed. It is not likely that the gene pool of a population will be affected the introduction of a new allele from a transmitted mutation.
11. Transposons are significant in creating of genetic variability because they are able to introduce small pieces of DNA into the genome. Over time, the work of transposons can create mutations and lead to selection.
12. Sexual recombination generates genetic variability by rearranging alleles into new combinations for each generation. In terms of time, this recombination is far more effective than mutation.
Natural Selection, Genetic Drift, and Gene Flow
13. “Only natural selection leads to the adaptation of organism to their environment” refers to the fact that individuals in a population vary in terms of heritable traits. Those better suited to the environment will reproduce better and produce more offspring. This natural selection determines which alleles will be passed on to the next generation and in what frequencies the alleles will exist in the population. Favorable genotypes are accumulated and maintained in a population through natural selection.
14. Genetic drift is the occurrence of chance events which change gene frequencies from generation to generation. According to the rules of probability, the larger the sample, the less chance of deviation from expected results. Thus, small population sizes mean greater chance of genetic drift.
15. The bottleneck effect is when a disaster drastically lowers the number of individuals in a large population. Certain alleles are overrepresented while others are unrepresented in the genotypes of the survivors, but only due to chance (not fitness). Certain alleles can be completely eliminated. Genetic drift will change the gene pool until the population is large enough for chance to no longer caused fluctuations. In terms of endangered species, the bottleneck effect is important in conservation biology. Genetic variation has been lost and the ability to adapt is reduced.
The founder effect happens when a few individuals who don’t represent the gene pool of the larger source population start a new population. Genetic drift would occur (as with the bottleneck) until the size of the population was large enough to avoid chance fluctuations. An example would be with human colonists.
16. Gene flow is genetic exchange caused by the migration of gametes or fertile individuals between populations. This process reduces genetic difference between adjacent populations because alleles mix and, if the extensive enough, neighboring populations may actually, over time, become one population with a common gene pool.
Genetic Variation, the Substrate for Natural Selection
17. Both quantitative characters—ones that vary along a continuum--and discrete ones, which are determined by a single locus with alleles that produce distinct phenotypes, contribute to variation within a population.
18. Average heterozygosity is a measure of gene variability, specifically the average percent of heterozygous gene loci. Nucleotide variability is a measure of the average level of difference between nucleotide sequences/base pairs among a population’s individuals. Average heterozygosity is generally greater than nucleotide diversity because genes consist of thousands of DNA bases. A small difference in one base is enough to make 2 alleles for that gene different, and thus count towards the average heterozygosity.
19. A cline occurs along a geographic axis, and is a variation in the form of a graded change in a trait. Clines can represent either zones where (1) neighboring populations with genetically different individuals interbred, or (2) natural selection based upon environmental variation
20. Relative fitness is the contribution to the next generation of one genotype compared to alternatives for the same locus. The relative fitness of an allele depends on the entire genetic and environmental context in which it is expressed. Survival does not guarantee reproductive success. A sterile organism, no matter how strong or long-lived, has a relative fitness of zero because it will not pass on its traits to any offspring.
21. Directional selection is common when the environment is changing or when migration occurs to a new habitat with different environmental conditions. The frequency curve of a phenotype shift in one direction, favoring individuals who deviate from the average. For example, the average size of European black bears went up during the glacial period, but decreased with subsequent warming. This change was due to the differences in the population’s need for conserving body heat.
When environmental conditions favor individuals at both of the phenotypic extremes instead of the intermediate range, disruptive selection occurs. For example, in Cameroon, the black-bellied seedcrackers have two very different bill types: one large, for feeding on hard seeds, and one small, for feeding on soft seeds. Birds with bills in-between those two sizes are inefficient at feeding on either of the seeds, and thus have lower relative fitness.
Stabilizing selection maintains a trait’s status quo. Variation is reduced as intermediate variants are selected for, and extreme phenotypes are selected against. Human birth weight is a clear case in which babies larger or small than 3 or 4 kg have high infant mortality rates (as opposed to ones than fit that range).
22. Diploidy can protect rare recessive alleles from elimination by natural selection by preserving or restoring variating. Because recessive alleles do not affect the phenotype in heterozygotes, “unfavorable” traits can persist and be passed down in a population through individuals that carry both alleles. Recessive alleles are thus exposed to selection only when expressed—when an individual carries two.
23. Balanced polymorphism occurs when natural selection maintains stable frequencies in a population of at least two phenotypes. This state is promoted by heterozygote advantage and frequency-dependent selection. The first maintains genetic diversity through the existence of a “inert” recessive allele in a heterozygous individual. Because the trait is not expressed, it cannot be selected against, but can be passed down to offspring. The trait will never be completed eliminated. Frequency-dependent selection involves the declination of any one phenotype in a population if it becomes too common. This most often occurs through predators, who develop a sense of the most widespread form of prey. These individuals thus become more vulnerable to predation and their numbers are lowered.
24. Neutral variations have insignificant impact on relative fitness, and thus are not affected by natural selection. Because there is no advantage of disadvantage to them, they do no matter.
25. Intrasexual selection is direct competition among individuals of the same sex (generally males) for mates of the opposite sex. This can take the form of physical battles, displays of dominance, etc. Intersexual selection, on the other hand, occurs when members of one sex are choosy in selecting their mates of the opposite sex. Since females generally invest more in eggs and parental care, they tend to be choosier about their mates, selecting males that will produce the “best” (well fit) offspring.
26. A female’s preference for showy male traits might actually benefit the female because the mates they pick will have enhanced fitness. Males will less showy traits may often have worse health. Each time a mate is picked based on appearance or behavior, the alleles that allowed them to be picked are passed down to the offspring, thus better enabling them to acquire mates and produce their own offspring.
27. Sexual reproduction is disadvantageous because it is not a powerful mechanism in terms of rapid population growth. It is far inferior to asexual reproduction in terms of the number of offspring produced. Despite the... [UNFINISHED]
28. The genetic variation promoted by sex may be advantageous to individuals on a generational time scale in terms of disease resistance. Offspring that vary in resistance to difference diseases are advantageous to a population. Sex provides a mechanism for changing allele distribution and varying them among individuals.
29. Natural selection cannot produce perfection because historical constraints limit evolution. Ancestral features cannot be gotten rid of—complex structures and behavior either remain as they are, or change slightly. Existing features only adapt to new situations. Adaptations involve compromises with the many things organisms must do (i.e. the seal flippers, which allow for both movement on land and in water). Natural selection interacts with change events which affect a population’s subsequent evolutionary history. Selection is only able to edit existing variation—the fittest variation are picked from the available phenotypes. New alleles cannot arise upon demand. The many imperfections of living organisms are evidence for evolution.
Population Genetics
1. The statement, “It is the population, not the individual, that evolves” means that while the impact of evolution can be seen in an organism, evolution is defined as the changes in a population over time. The impact of natural selection is apparent only in the relative reproductive success of individuals based on their combinations of inherited traits.
2. Darwin’s explanation needed support that to explain how chance variation arise in a population, and how variations are passed down from parents to offspring. At the time that Darwin introduced his theory, the belief was that parents passed down a blend of their traits to their offspring. Over time, this process would eliminate differences between individuals. Mendel’s particulate hypothesis of inheritance support Darwin’s theory of evolution by natural selection because it stated that parents pass on discrete heritable units (today we call them genes), which retain their identities in offspring.
3. Discrete heritable traits are referred to as genes today. These units retain their identities in offspring. Discrete traits are influenced by a single loci. They are “either-or.” Quantitative traits vary along a continuum. Their characters are influenced by multiple loci. Quantitative traits have a genetic basis, and the alleles at each of the multiple loci follow the Mendelian laws of inheritance
4. The “modern synthesis” is a comprehensive theory of evolution, which came about in the 1940s. Integrating paleontology, taxonomy, biogeography, and population genetics, it emphasizes three mains things:
The unit of evolution is a population
Natural selection has a central role as the most important mechanism of adaptive evolution
Large changes can evolve from an accumulation of small changes over long periods of times (gradualism)
5. A contained group of individuals belonging to the same species is defined as a population. A species is a group of individuals who are able to interbreed and produce viable, fertile offspring. A population’s gene pool is its complete collection of genes at any given time. A gene pool is made of all the alleles at all the gene loci in all the population’s individuals.
6. Meiosis and random fertilization alone will not alter the frequency of alleles or genotypes in a population because [UNFINISHED]
7. For a population to remain in the Hardy-Weinberg equilibrium five conditions must be met, being:
The population size is extremely large (small populations have genetic drift)
Random mating must occur (if individuals pick mates with certain genotypes or inbreeding offcurs, gametes will not mix randomly)
There is no gene flow, or transfer of alleles (which can change the allele proportion)
There are no mutations (any gene modification, introduction, or loss will alter the gene pool)
There is no natural selection (differential survival/reproductive success will alter genotype frequencies)
8. The Hardy Weinberg equation is as follows: p2 + 2pq + q2 = 1.0
When the frequency of homozygous recessive individuals in a population is 25%, the allele frequencies would be:
q-squared = .25 --> q = .5
p = .5
Mutation and Sexual Recombination
9. The majority of point mutations, which are changes in a single base of a gene, are harmless because most eukaryotic genomes don’t code for protein products. Also, because the genetic code is redundant, so point mutations may not have any affect.
10. Mutations have little quantitative effect on allele frequencies in a large population because most occur in somatic cells and thus disappear when the organism dies. The few mutations in cell lines that form gametes are passed to offspring, but only a fraction of them spread and become fixed. It is not likely that the gene pool of a population will be affected the introduction of a new allele from a transmitted mutation.
11. Transposons are significant in creating of genetic variability because they are able to introduce small pieces of DNA into the genome. Over time, the work of transposons can create mutations and lead to selection.
12. Sexual recombination generates genetic variability by rearranging alleles into new combinations for each generation. In terms of time, this recombination is far more effective than mutation.
Natural Selection, Genetic Drift, and Gene Flow
13. “Only natural selection leads to the adaptation of organism to their environment” refers to the fact that individuals in a population vary in terms of heritable traits. Those better suited to the environment will reproduce better and produce more offspring. This natural selection determines which alleles will be passed on to the next generation and in what frequencies the alleles will exist in the population. Favorable genotypes are accumulated and maintained in a population through natural selection.
14. Genetic drift is the occurrence of chance events which change gene frequencies from generation to generation. According to the rules of probability, the larger the sample, the less chance of deviation from expected results. Thus, small population sizes mean greater chance of genetic drift.
15. The bottleneck effect is when a disaster drastically lowers the number of individuals in a large population. Certain alleles are overrepresented while others are unrepresented in the genotypes of the survivors, but only due to chance (not fitness). Certain alleles can be completely eliminated. Genetic drift will change the gene pool until the population is large enough for chance to no longer caused fluctuations. In terms of endangered species, the bottleneck effect is important in conservation biology. Genetic variation has been lost and the ability to adapt is reduced.
The founder effect happens when a few individuals who don’t represent the gene pool of the larger source population start a new population. Genetic drift would occur (as with the bottleneck) until the size of the population was large enough to avoid chance fluctuations. An example would be with human colonists.
16. Gene flow is genetic exchange caused by the migration of gametes or fertile individuals between populations. This process reduces genetic difference between adjacent populations because alleles mix and, if the extensive enough, neighboring populations may actually, over time, become one population with a common gene pool.
Genetic Variation, the Substrate for Natural Selection
17. Both quantitative characters—ones that vary along a continuum--and discrete ones, which are determined by a single locus with alleles that produce distinct phenotypes, contribute to variation within a population.
18. Average heterozygosity is a measure of gene variability, specifically the average percent of heterozygous gene loci. Nucleotide variability is a measure of the average level of difference between nucleotide sequences/base pairs among a population’s individuals. Average heterozygosity is generally greater than nucleotide diversity because genes consist of thousands of DNA bases. A small difference in one base is enough to make 2 alleles for that gene different, and thus count towards the average heterozygosity.
19. A cline occurs along a geographic axis, and is a variation in the form of a graded change in a trait. Clines can represent either zones where (1) neighboring populations with genetically different individuals interbred, or (2) natural selection based upon environmental variation
20. Relative fitness is the contribution to the next generation of one genotype compared to alternatives for the same locus. The relative fitness of an allele depends on the entire genetic and environmental context in which it is expressed. Survival does not guarantee reproductive success. A sterile organism, no matter how strong or long-lived, has a relative fitness of zero because it will not pass on its traits to any offspring.
21. Directional selection is common when the environment is changing or when migration occurs to a new habitat with different environmental conditions. The frequency curve of a phenotype shift in one direction, favoring individuals who deviate from the average. For example, the average size of European black bears went up during the glacial period, but decreased with subsequent warming. This change was due to the differences in the population’s need for conserving body heat.
When environmental conditions favor individuals at both of the phenotypic extremes instead of the intermediate range, disruptive selection occurs. For example, in Cameroon, the black-bellied seedcrackers have two very different bill types: one large, for feeding on hard seeds, and one small, for feeding on soft seeds. Birds with bills in-between those two sizes are inefficient at feeding on either of the seeds, and thus have lower relative fitness.
Stabilizing selection maintains a trait’s status quo. Variation is reduced as intermediate variants are selected for, and extreme phenotypes are selected against. Human birth weight is a clear case in which babies larger or small than 3 or 4 kg have high infant mortality rates (as opposed to ones than fit that range).
22. Diploidy can protect rare recessive alleles from elimination by natural selection by preserving or restoring variating. Because recessive alleles do not affect the phenotype in heterozygotes, “unfavorable” traits can persist and be passed down in a population through individuals that carry both alleles. Recessive alleles are thus exposed to selection only when expressed—when an individual carries two.
23. Balanced polymorphism occurs when natural selection maintains stable frequencies in a population of at least two phenotypes. This state is promoted by heterozygote advantage and frequency-dependent selection. The first maintains genetic diversity through the existence of a “inert” recessive allele in a heterozygous individual. Because the trait is not expressed, it cannot be selected against, but can be passed down to offspring. The trait will never be completed eliminated. Frequency-dependent selection involves the declination of any one phenotype in a population if it becomes too common. This most often occurs through predators, who develop a sense of the most widespread form of prey. These individuals thus become more vulnerable to predation and their numbers are lowered.
24. Neutral variations have insignificant impact on relative fitness, and thus are not affected by natural selection. Because there is no advantage of disadvantage to them, they do no matter.
25. Intrasexual selection is direct competition among individuals of the same sex (generally males) for mates of the opposite sex. This can take the form of physical battles, displays of dominance, etc. Intersexual selection, on the other hand, occurs when members of one sex are choosy in selecting their mates of the opposite sex. Since females generally invest more in eggs and parental care, they tend to be choosier about their mates, selecting males that will produce the “best” (well fit) offspring.
26. A female’s preference for showy male traits might actually benefit the female because the mates they pick will have enhanced fitness. Males will less showy traits may often have worse health. Each time a mate is picked based on appearance or behavior, the alleles that allowed them to be picked are passed down to the offspring, thus better enabling them to acquire mates and produce their own offspring.
27. Sexual reproduction is disadvantageous because it is not a powerful mechanism in terms of rapid population growth. It is far inferior to asexual reproduction in terms of the number of offspring produced. Despite the... [UNFINISHED]
28. The genetic variation promoted by sex may be advantageous to individuals on a generational time scale in terms of disease resistance. Offspring that vary in resistance to difference diseases are advantageous to a population. Sex provides a mechanism for changing allele distribution and varying them among individuals.
29. Natural selection cannot produce perfection because historical constraints limit evolution. Ancestral features cannot be gotten rid of—complex structures and behavior either remain as they are, or change slightly. Existing features only adapt to new situations. Adaptations involve compromises with the many things organisms must do (i.e. the seal flippers, which allow for both movement on land and in water). Natural selection interacts with change events which affect a population’s subsequent evolutionary history. Selection is only able to edit existing variation—the fittest variation are picked from the available phenotypes. New alleles cannot arise upon demand. The many imperfections of living organisms are evidence for evolution.
Wednesday, January 9, 2008
AP Psychology Ch10 vocab
1. Intelligence Quotients, also known as IQs, are established by dividing one’s mental age—which is determined by calculating the age level of the most advanced items consistently answered correctly on an IQ test—by one’s actual age and multiplying that number by 100. Thus, “average” intelligence is represented by an IQ of 100. IQ scores reflect relative standing within a population of one’s age.
2. The verbal scale is the part of the IQ test that involves the six subtests that require verbal skills—such as defining vocabulary or answering questions.
3. The performance scale is made up by the five subtests of the IQ test that have little or no verbal content, such as understanding how to manipulate materials or relate objects in space.
4. Aptitude tests measure one’s capacity to learn or perform certain things and are ultimately supposed to assess one’s potential. The SAT and ACT are included in this category of tests.
5. Achievement tests measure accomplishments and knowledge of particular areas. They may focus on specific abilities.
6. Norms are calculated using test scores that summarize a test taker’s performance. They give us percentages and enable people to determine what is below or above average.
7. Reliability refers to when a test has repeatable or stable results.
8. Validity is a degree to which a test measures what it intended to measure. There are several types of validity. Content validity is the extent to which the test’s content relates to what it is supposed to measure (i.e. only math on an intelligence test = low validity). Construct validity is the degree to which test scores are in accordance with the theory on what is being tested. Criterion validity is how much test scores correlate with another direct and independent measure of what the test supposedly assesses.
9. Factor Analysis is when correlations are analyzed to identify underlying aspects. When analyzing the factors of intelligence, factors such as verbal fluency, numerical ability, and memory were found.
10. Fluid Intelligence refers to basic reasoning and problem solving, and allows people to evaluate, think critically, and understand concepts.
11. Crystallized Intelligence involves specific knowledge gained from using fluid intelligence, such as vocabulary.
12. The Information Processing Approach analyzes the process of intelligent behavior, as opposed to the products of intelligence. It looks at mental operations necessary and focuses on aspects of learning, attention, memory, and processing.
13. Sternberg’s Triarchic Theory of Intelligence deals with three different types of intelligence, namely practical (problem solving), creative, and analytic (measured by traditional IQ tests) intelligence. Sternberg believed that all facets of intelligence were necessary.
14. Howard Gardner’s theory of Multiple Intelligences was based on the idea that people possess more than on intellectual potential and that each of these intelligences involves problem solving skills. The eight specific intelligences proposed were: linguistic intelligence, spatial intelligence, body-kinesthetic intelligence, logical-mathematical intelligence, musical intelligence, intrapersonal intelligence, interpersonal intelligence, and naturalistic intelligence.
15. Divergent Thinking is the ability to creatively think along numerous paths in order to come up with many solutions to one problem.
16. Convergent Thinking is measured by traditional IQ tests. It is the ability to apply knowledge and logic to narrow down the number of possible solutions to a problem.
17. Familial Retardation is mild retardation typical seen in people who come from a family of low socioeconomic status and are likely to have a relative who is also retarded (more so than those with retardation who suffered a genetic defect). People with mild retardation may perform mental tasks more slowly and may not be skilled at problem solving or retaining facts.
18. Metacognition is the knowledge of what strategies to apply when necessary, and how to use and adapt these strategies when in new situations in order to gain knowledge and mast problems.
2. The verbal scale is the part of the IQ test that involves the six subtests that require verbal skills—such as defining vocabulary or answering questions.
3. The performance scale is made up by the five subtests of the IQ test that have little or no verbal content, such as understanding how to manipulate materials or relate objects in space.
4. Aptitude tests measure one’s capacity to learn or perform certain things and are ultimately supposed to assess one’s potential. The SAT and ACT are included in this category of tests.
5. Achievement tests measure accomplishments and knowledge of particular areas. They may focus on specific abilities.
6. Norms are calculated using test scores that summarize a test taker’s performance. They give us percentages and enable people to determine what is below or above average.
7. Reliability refers to when a test has repeatable or stable results.
8. Validity is a degree to which a test measures what it intended to measure. There are several types of validity. Content validity is the extent to which the test’s content relates to what it is supposed to measure (i.e. only math on an intelligence test = low validity). Construct validity is the degree to which test scores are in accordance with the theory on what is being tested. Criterion validity is how much test scores correlate with another direct and independent measure of what the test supposedly assesses.
9. Factor Analysis is when correlations are analyzed to identify underlying aspects. When analyzing the factors of intelligence, factors such as verbal fluency, numerical ability, and memory were found.
10. Fluid Intelligence refers to basic reasoning and problem solving, and allows people to evaluate, think critically, and understand concepts.
11. Crystallized Intelligence involves specific knowledge gained from using fluid intelligence, such as vocabulary.
12. The Information Processing Approach analyzes the process of intelligent behavior, as opposed to the products of intelligence. It looks at mental operations necessary and focuses on aspects of learning, attention, memory, and processing.
13. Sternberg’s Triarchic Theory of Intelligence deals with three different types of intelligence, namely practical (problem solving), creative, and analytic (measured by traditional IQ tests) intelligence. Sternberg believed that all facets of intelligence were necessary.
14. Howard Gardner’s theory of Multiple Intelligences was based on the idea that people possess more than on intellectual potential and that each of these intelligences involves problem solving skills. The eight specific intelligences proposed were: linguistic intelligence, spatial intelligence, body-kinesthetic intelligence, logical-mathematical intelligence, musical intelligence, intrapersonal intelligence, interpersonal intelligence, and naturalistic intelligence.
15. Divergent Thinking is the ability to creatively think along numerous paths in order to come up with many solutions to one problem.
16. Convergent Thinking is measured by traditional IQ tests. It is the ability to apply knowledge and logic to narrow down the number of possible solutions to a problem.
17. Familial Retardation is mild retardation typical seen in people who come from a family of low socioeconomic status and are likely to have a relative who is also retarded (more so than those with retardation who suffered a genetic defect). People with mild retardation may perform mental tasks more slowly and may not be skilled at problem solving or retaining facts.
18. Metacognition is the knowledge of what strategies to apply when necessary, and how to use and adapt these strategies when in new situations in order to gain knowledge and mast problems.
AP Psychology Ch8 vocab
1. Evoked brain potentials is a small, temporary change in voltage on an EEG that occurs in response to specific events.
2. Cognitive maps are mental representations of familiar parts of one’s world that are carried in one’s memory.
3. Prototypes are members of a natural concept that possess all or most of its characteristic features.
4. Schemas are mental representations or generalizations we develop about categories or objects, events, and people.
5. Scripts are schemas about familiar sequences of events or activities.
6. Propositions are ideas about the relationships between and among concepts, relating one concept to another.
7. Mental models are clusters of propositions that contain our understanding of how things work.
8. Algorithms are systematic methods that always produce a correct solution to a problem, if a solution exists.
9. Heuristics are mental shortcuts one takes to reach a conclusion that is probably, but not necessarily, correct.
10. Representativeness heuristic s where people decide whether an example belongs in a certain class on the basis of how similar it is to the other items in that class.
11. Availability heuristic involves judging the probability that an event may occur or that a hypothesis may be true by how easily the hypothesis or examples of the event can be brought to the mind.
12. Functional fixedness is the tendency to use familiar objects in familiar rather than creative ways.
13. Confirmation bias states that humans have a strong bias to confirm rather than to refute the hypothesis they have chosen.
14. Artificial intelligence is the ability for computer systems to imitate the products of human perception and thought.
15. In group polarization, discussions favor the majority view and criticize the minority view, thus having a tendency towards making extreme decisions.
16. Grammar is the set of rules for combining symbols, or words.
17. Phonemes are defined as the smallest unit of sound that affects the meaning of speech.
18. Morphemes are the smallest unit or language that has meaning.
19. Syntax is the set of grammatical rules that determine how words are combined to form sentences.
20. Semantics is the set of rules that governs the meaning of words and sentences.
21. Surface structures, or word strings that people produce, contain deep structure, or an abstract representation of the relationships expressed in the sentence.
22. Telegraphic speech consists of two-word pairs that are brief and to the point, leaving our any word that’s not essential.
2. Cognitive maps are mental representations of familiar parts of one’s world that are carried in one’s memory.
3. Prototypes are members of a natural concept that possess all or most of its characteristic features.
4. Schemas are mental representations or generalizations we develop about categories or objects, events, and people.
5. Scripts are schemas about familiar sequences of events or activities.
6. Propositions are ideas about the relationships between and among concepts, relating one concept to another.
7. Mental models are clusters of propositions that contain our understanding of how things work.
8. Algorithms are systematic methods that always produce a correct solution to a problem, if a solution exists.
9. Heuristics are mental shortcuts one takes to reach a conclusion that is probably, but not necessarily, correct.
10. Representativeness heuristic s where people decide whether an example belongs in a certain class on the basis of how similar it is to the other items in that class.
11. Availability heuristic involves judging the probability that an event may occur or that a hypothesis may be true by how easily the hypothesis or examples of the event can be brought to the mind.
12. Functional fixedness is the tendency to use familiar objects in familiar rather than creative ways.
13. Confirmation bias states that humans have a strong bias to confirm rather than to refute the hypothesis they have chosen.
14. Artificial intelligence is the ability for computer systems to imitate the products of human perception and thought.
15. In group polarization, discussions favor the majority view and criticize the minority view, thus having a tendency towards making extreme decisions.
16. Grammar is the set of rules for combining symbols, or words.
17. Phonemes are defined as the smallest unit of sound that affects the meaning of speech.
18. Morphemes are the smallest unit or language that has meaning.
19. Syntax is the set of grammatical rules that determine how words are combined to form sentences.
20. Semantics is the set of rules that governs the meaning of words and sentences.
21. Surface structures, or word strings that people produce, contain deep structure, or an abstract representation of the relationships expressed in the sentence.
22. Telegraphic speech consists of two-word pairs that are brief and to the point, leaving our any word that’s not essential.
AP Psychology Ch7 vocab
1. Encoding is a step in the process in which information to be remembered is put into a memory. This occurs when sensory information is put into a form that is accepted and used by the memory system.
2. Storage, the maintenance of information over a period of time, is the second basic memory process.
3. The third basic memory process is called retrieval. Retrieval involves locating information stored in one’s memory and brining it into consciousness. It may include both recall (retrieval without assistance) and recognition (retrieval of information using clues).
4. Episodic memory involve a specific event that occurred while you were present (“I remember when...”).
5. Semantic memory is involves generalized knowledge and does not involves specific events (“I know that...”).
6. Procedural memory is often difficult to describe or explain verbally, and may involve a complicated sequence of movements. These memories involve remembering how to do things.
7. Maintenance rehearsal involves repeating an item over and over. It is often effective for remembering information for a short period of time.
8. Elaborative rehearsal is a more effective type of mental rehearsal that will help you remember something for a long period of time. It involves thinking about how new material relates to known material already stored in your memory
9. Transfer-appropriate processing suggests that memories ultimate depend on and are affected by how well encoding processes match up with information retrieval.
10. Parallel Distributed Processing (PDP) is an approach to memory that suggests that new experiences become integrated with people’s existing knowledge or memories, and aren’t simply “new facts.”
11. Sensory memories hold information long enough for it to be processes. Because incoming stimuli must be analyzed by the brain and compared to what is already in the long term memory, sensory stimuli need to be stored briefly, but completely. Sensory registers hold fleeting memories, but are capable of storing relatively large amounts of information.
12. Selective attention focuses mental resources on only a part of the stimulus field and therefore controls what information is processed further.
13. Chunks refer to the number of meaningful groupings of information.
14. Primary effect is the tendency of the first two-three words in a list to be recalled very well, whereas recency effect is the ease of recalling words near the end of the list.
15. Memory is state-dependant when a person’s internal state can aid or impede retrieval.
16. Decay is the gradual disappearance of the mental representation of a stimulus as it becomes less distinct over time.
17. Interference is a process through which the storage or retrieval of information in impaired by the presence of other information.
18. Using long-term memory retroactive interference occurs when the learning of new information interferes with the recall of old information.
19. Also using long-term memory, proactive interference occurs when old information interferers with learning and remembering old information.
20. Anterograde amnesia is a loss of memory for any events occurring after the injury.
21. Retrograde amnesia is a loss of memory for any event that occurred before the injury.
22. Mnemonics are strategies for placing information into a context that is organized to help information retrieval (i.e. accronyms).
2. Storage, the maintenance of information over a period of time, is the second basic memory process.
3. The third basic memory process is called retrieval. Retrieval involves locating information stored in one’s memory and brining it into consciousness. It may include both recall (retrieval without assistance) and recognition (retrieval of information using clues).
4. Episodic memory involve a specific event that occurred while you were present (“I remember when...”).
5. Semantic memory is involves generalized knowledge and does not involves specific events (“I know that...”).
6. Procedural memory is often difficult to describe or explain verbally, and may involve a complicated sequence of movements. These memories involve remembering how to do things.
7. Maintenance rehearsal involves repeating an item over and over. It is often effective for remembering information for a short period of time.
8. Elaborative rehearsal is a more effective type of mental rehearsal that will help you remember something for a long period of time. It involves thinking about how new material relates to known material already stored in your memory
9. Transfer-appropriate processing suggests that memories ultimate depend on and are affected by how well encoding processes match up with information retrieval.
10. Parallel Distributed Processing (PDP) is an approach to memory that suggests that new experiences become integrated with people’s existing knowledge or memories, and aren’t simply “new facts.”
11. Sensory memories hold information long enough for it to be processes. Because incoming stimuli must be analyzed by the brain and compared to what is already in the long term memory, sensory stimuli need to be stored briefly, but completely. Sensory registers hold fleeting memories, but are capable of storing relatively large amounts of information.
12. Selective attention focuses mental resources on only a part of the stimulus field and therefore controls what information is processed further.
13. Chunks refer to the number of meaningful groupings of information.
14. Primary effect is the tendency of the first two-three words in a list to be recalled very well, whereas recency effect is the ease of recalling words near the end of the list.
15. Memory is state-dependant when a person’s internal state can aid or impede retrieval.
16. Decay is the gradual disappearance of the mental representation of a stimulus as it becomes less distinct over time.
17. Interference is a process through which the storage or retrieval of information in impaired by the presence of other information.
18. Using long-term memory retroactive interference occurs when the learning of new information interferes with the recall of old information.
19. Also using long-term memory, proactive interference occurs when old information interferers with learning and remembering old information.
20. Anterograde amnesia is a loss of memory for any events occurring after the injury.
21. Retrograde amnesia is a loss of memory for any event that occurred before the injury.
22. Mnemonics are strategies for placing information into a context that is organized to help information retrieval (i.e. accronyms).
AP Psychology Ch6 vocab
1. Habituation is a form of learning that occurs when our responsiveness to unchanging stimuli over time decreases as a result of our adapting to that stimuli.
2. Classical Conditioning is a basic form of associative learning, when a neutral stimulus is repeatedly paired with a stimulus that naturally triggers a reflexive response, until the formerly neutral stimulus evokes a similar response to the reflex without the reflex triggering stimulus.
3. Extinction is when a conditioned response gradually over time disappears when the unconditioned stimulus (which originally triggered an automatic response without conditioning) is no longer paired with the conditioned stimulus (which originally triggered only a neutral reaction or none at all).
4. If, after the conditioned response has disappeared or become extinct, the conditioned stimulus and unconditioned stimulus are paired again, reconditioning occurs, and the conditioned response will return to its original strength very quickly after a short period of time (less then the original conditioning).
5. Spontaneous recovery is when an extinguished conditioned response will temporarily occur again when the conditioned stimulus is present, even though the unconditioned stimulus is absent. This reappearance of the conditioned response after extinction does not require further conditioned stimulus and unconditioned stimulus pairings. In fact, the longer the time between the extinction of the conditioned response and the re-presentation of the conditioned stimulus, the stronger the recovered conditioned response generally is.
6. Stimulus discrimination is when organisms differentiate among similar stimuli, so that not all stimuli will result in a conditioned response through stimulus generalization.
7. Second-order conditioning is when a conditioned stimulus acts like an unconditional (natural) stimulus and creates a conditioned stimuli out of associated events.
8. The Law of Effect states that a response will be more likely to occur in the presence of a certain stimulus if that that response was previously followed by satisfaction or reward when that same stimulus was present. Conversely, responses that produce discomfort are less likely to be performed again in the presence of that stimuli.
9. Instrumental Conditioning is the type of learning in which certain responses are strengthened and more likely to occur in the future because those response are instrumental in producing rewards.
10. Positive Reinforcement works like a reward, and is when a response is strengthened or increased because pleasant or positive stimuli occurs after certain behavior. The behavior will thus be repeated because it causes desirable outcomes.
11. Negative Reinforcement occurs when unpleasant stimuli are removed or terminated upon a certain response or behavior, and thus strengthen the likelihood that such behavior will be repeated in the future.
12. Escape Conditioning occurs when an organism learns to respond a certain way in order to end or terminate an aversive stimulus or negative reinforcer.
13. Avoidance Conditioning is when an organism makes a connection between a certain stimulus and an event that is linked with that stimulus. When the stimulus occurs or becomes present, the organism thus reacts or respond to the signal so as to avoid or prevent the exposure to a certain aversive event. This conditioning is a mix of both classical and operant conditioning because it involves both a conditioned stimulus (pairing signal with unwanted event) and the reinforcement through consequences.
14. Punishment works in the opposite manner of positive and negative reinforcement by decreasing the likelihood that behavior will occur by following a certain operant behavior with an aversive or unpleasant stimulus or deprivation of a pleasant stimulus (penalty).
15. Discriminative stimuli are stimuli that signal whether reinforcement (reward) is available if a certain response is made. They allow organisms to learn what is appropriate in certain situations and inappropriate in others, as the organisms learn to make particular responses in the presence of one stimulus but not another.
16. Shaping reinforcement of behavior through successive approximations. Reinforcement drives the responses closer to the desired response, through steps.
17. Primary reinforcers are inherently rewarding events or stimuli. They may cause problems, however, because if the reinforcement is something like food, over time it will become less powerful, because hunger and desire for the food will diminish. Time will also be lost to consumption. Thus, previously neutral stimuli called secondary reinforcers are used. Secondary reinforcers (aka conditioned reinforcers) are paired with naturally reinforcing stimuli and then become reward-like in themselves and are learned to be liked.
18. Vicarious Conditioning is a type of observational learning when seeing or hearing the consequences of others’ behavior influences one’s own behavior.
19. Operant Conditioning is similar to instrumental conditioning, except that it emphasize how an organism learns to responses certain ways through operating on its environment. Behavior changed through consequences.
20. Observational Learning occurs through watching others, and is efficient and adaptive way of learning socially. Children are generally very easily influenced by adults and peers who they see as models for “appropriate behavior.”
2. Classical Conditioning is a basic form of associative learning, when a neutral stimulus is repeatedly paired with a stimulus that naturally triggers a reflexive response, until the formerly neutral stimulus evokes a similar response to the reflex without the reflex triggering stimulus.
3. Extinction is when a conditioned response gradually over time disappears when the unconditioned stimulus (which originally triggered an automatic response without conditioning) is no longer paired with the conditioned stimulus (which originally triggered only a neutral reaction or none at all).
4. If, after the conditioned response has disappeared or become extinct, the conditioned stimulus and unconditioned stimulus are paired again, reconditioning occurs, and the conditioned response will return to its original strength very quickly after a short period of time (less then the original conditioning).
5. Spontaneous recovery is when an extinguished conditioned response will temporarily occur again when the conditioned stimulus is present, even though the unconditioned stimulus is absent. This reappearance of the conditioned response after extinction does not require further conditioned stimulus and unconditioned stimulus pairings. In fact, the longer the time between the extinction of the conditioned response and the re-presentation of the conditioned stimulus, the stronger the recovered conditioned response generally is.
6. Stimulus discrimination is when organisms differentiate among similar stimuli, so that not all stimuli will result in a conditioned response through stimulus generalization.
7. Second-order conditioning is when a conditioned stimulus acts like an unconditional (natural) stimulus and creates a conditioned stimuli out of associated events.
8. The Law of Effect states that a response will be more likely to occur in the presence of a certain stimulus if that that response was previously followed by satisfaction or reward when that same stimulus was present. Conversely, responses that produce discomfort are less likely to be performed again in the presence of that stimuli.
9. Instrumental Conditioning is the type of learning in which certain responses are strengthened and more likely to occur in the future because those response are instrumental in producing rewards.
10. Positive Reinforcement works like a reward, and is when a response is strengthened or increased because pleasant or positive stimuli occurs after certain behavior. The behavior will thus be repeated because it causes desirable outcomes.
11. Negative Reinforcement occurs when unpleasant stimuli are removed or terminated upon a certain response or behavior, and thus strengthen the likelihood that such behavior will be repeated in the future.
12. Escape Conditioning occurs when an organism learns to respond a certain way in order to end or terminate an aversive stimulus or negative reinforcer.
13. Avoidance Conditioning is when an organism makes a connection between a certain stimulus and an event that is linked with that stimulus. When the stimulus occurs or becomes present, the organism thus reacts or respond to the signal so as to avoid or prevent the exposure to a certain aversive event. This conditioning is a mix of both classical and operant conditioning because it involves both a conditioned stimulus (pairing signal with unwanted event) and the reinforcement through consequences.
14. Punishment works in the opposite manner of positive and negative reinforcement by decreasing the likelihood that behavior will occur by following a certain operant behavior with an aversive or unpleasant stimulus or deprivation of a pleasant stimulus (penalty).
15. Discriminative stimuli are stimuli that signal whether reinforcement (reward) is available if a certain response is made. They allow organisms to learn what is appropriate in certain situations and inappropriate in others, as the organisms learn to make particular responses in the presence of one stimulus but not another.
16. Shaping reinforcement of behavior through successive approximations. Reinforcement drives the responses closer to the desired response, through steps.
17. Primary reinforcers are inherently rewarding events or stimuli. They may cause problems, however, because if the reinforcement is something like food, over time it will become less powerful, because hunger and desire for the food will diminish. Time will also be lost to consumption. Thus, previously neutral stimuli called secondary reinforcers are used. Secondary reinforcers (aka conditioned reinforcers) are paired with naturally reinforcing stimuli and then become reward-like in themselves and are learned to be liked.
18. Vicarious Conditioning is a type of observational learning when seeing or hearing the consequences of others’ behavior influences one’s own behavior.
19. Operant Conditioning is similar to instrumental conditioning, except that it emphasize how an organism learns to responses certain ways through operating on its environment. Behavior changed through consequences.
20. Observational Learning occurs through watching others, and is efficient and adaptive way of learning socially. Children are generally very easily influenced by adults and peers who they see as models for “appropriate behavior.”
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