Lecture 20 Macroevolution
... Hypothesis: Characters evolve primarily in concert with true speciation (cladogenesis). If new species evolve primarily in marginal populations, then the transitions will almost never be observed in the fossil record. Recall our discussion of rapid divergence in peripheral populations (i.e., ...
... Hypothesis: Characters evolve primarily in concert with true speciation (cladogenesis). If new species evolve primarily in marginal populations, then the transitions will almost never be observed in the fossil record. Recall our discussion of rapid divergence in peripheral populations (i.e., ...
How Populations Evolve
... Ex – When Cepaea snails vary because a wide geographic range causes selection to vary ...
... Ex – When Cepaea snails vary because a wide geographic range causes selection to vary ...
Speciation: Darwin revisited
... Phyletic gradualism: the view that species evolve by gradual lineage evolution (anagenesis) and splitting (speciation) as a subsidiary process. Phylogenetic tree: an estimate of the true phylogeny, for example as might be reconstructed from species characters such as molecular data. Often shortened ...
... Phyletic gradualism: the view that species evolve by gradual lineage evolution (anagenesis) and splitting (speciation) as a subsidiary process. Phylogenetic tree: an estimate of the true phylogeny, for example as might be reconstructed from species characters such as molecular data. Often shortened ...
the channel capacity of selective breeding
... information is encoded strongly affects the amount of information that can be maintained. In principle, vastly more information may be maintained at equilibrium if information is encoded diffusely in very long genomes. For such diffuse encoding, the amount of information that can be stored is propor ...
... information is encoded strongly affects the amount of information that can be maintained. In principle, vastly more information may be maintained at equilibrium if information is encoded diffusely in very long genomes. For such diffuse encoding, the amount of information that can be stored is propor ...
Mechanisms of Evolution 1 Chapter 22: Descent with Modification
... - Tends to reduce genetic variation through losses of alleles - These changes are often due to some random factor loss of alleles is not due to selection Founder effect occurs when a few individuals become isolated from a larger population - Allele frequencies in the small founder population can b ...
... - Tends to reduce genetic variation through losses of alleles - These changes are often due to some random factor loss of alleles is not due to selection Founder effect occurs when a few individuals become isolated from a larger population - Allele frequencies in the small founder population can b ...
File - Honors Biology 16-17
... Result = the variance increases as the population is divided into two distinct groups. Disruptive selection plays an important role in speciation. Stabilizing Selection occurs when selection favors the intermediate trait value over the extreme values. Result= a decrease in the amount of genetic va ...
... Result = the variance increases as the population is divided into two distinct groups. Disruptive selection plays an important role in speciation. Stabilizing Selection occurs when selection favors the intermediate trait value over the extreme values. Result= a decrease in the amount of genetic va ...
Chapter 18 - Population genetics
... genetic drift (chance events)/founder effect/population bottleneck • Non-random mating • Gene flow (individuals do leave or enter populations) • Natural selection-nature selects individuals in a population that have “favorable” alleles which allow for survival in a given ...
... genetic drift (chance events)/founder effect/population bottleneck • Non-random mating • Gene flow (individuals do leave or enter populations) • Natural selection-nature selects individuals in a population that have “favorable” alleles which allow for survival in a given ...
Microevolution
... reproduction eliminates variation. Sexual reproduction does not eliminate the frequency of alleles in a population. This idea have become known as the “Hardy-Weinberg ...
... reproduction eliminates variation. Sexual reproduction does not eliminate the frequency of alleles in a population. This idea have become known as the “Hardy-Weinberg ...
Current Issues in Cr..
... of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged." • Darwin skeptics: www.rae.org contains over 2000 names of trained scientists who are “skeptical.” And another 1000 who are not willing to s ...
... of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged." • Darwin skeptics: www.rae.org contains over 2000 names of trained scientists who are “skeptical.” And another 1000 who are not willing to s ...
27. Introduction to speciation, allopatric speciation
... constitute our currency. Their peculiar significance was long ago appreciated by Darwin’s mentor, Sir Charles Lyell: “The ordinary naturalist is not sufficiently aware that when dogmatizing about what species are, he is grappling with the whole question of the organic world and its connection with a ...
... constitute our currency. Their peculiar significance was long ago appreciated by Darwin’s mentor, Sir Charles Lyell: “The ordinary naturalist is not sufficiently aware that when dogmatizing about what species are, he is grappling with the whole question of the organic world and its connection with a ...
Darwinian Aesthetics Informs Traditional Aesthetics
... Adaptationism In this paper, and in theoretical (evolutionary) biology in general, adaptation refers to goal-directed, i.e., functionally designed, phenotypic features (e.g., Thornhill 1990, 1997; Symons 1992; Williams 1992). As Williams (1992) put it, an adaptation is the material effect of respons ...
... Adaptationism In this paper, and in theoretical (evolutionary) biology in general, adaptation refers to goal-directed, i.e., functionally designed, phenotypic features (e.g., Thornhill 1990, 1997; Symons 1992; Williams 1992). As Williams (1992) put it, an adaptation is the material effect of respons ...
Chapter 23: The Evolution of Populations
... S The flow of insecticide resistance alleles into a ...
... S The flow of insecticide resistance alleles into a ...
Lesson 8.3
... • However, many animal species are selective when finding a mate. These individuals look for particular traits in a mate that will translate to an advantage for their offspring. Since this mating is no longer random, many undesirable alleles are bred out of the population over several generations. T ...
... • However, many animal species are selective when finding a mate. These individuals look for particular traits in a mate that will translate to an advantage for their offspring. Since this mating is no longer random, many undesirable alleles are bred out of the population over several generations. T ...
STABILIZING SELECTION ON HUMAN BIRTH WEIGHT GALL
... “A slow sort of country!” said the Queen. “Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else you must run at least twice as fast as that” F From Ali iin W Alice Wonderland d l d Lewis Carroll ...
... “A slow sort of country!” said the Queen. “Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else you must run at least twice as fast as that” F From Ali iin W Alice Wonderland d l d Lewis Carroll ...
Part 2 - Microevolution - Campbell Ch. 13
... equation is useful in public health science Public health scientists use the Hardy-Weinberg equation to estimate frequencies of diseasecausing alleles in the human population. One out of 10,000 babies born in the United States has phenylketonuria (PKU), an inherited inability to break down the a ...
... equation is useful in public health science Public health scientists use the Hardy-Weinberg equation to estimate frequencies of diseasecausing alleles in the human population. One out of 10,000 babies born in the United States has phenylketonuria (PKU), an inherited inability to break down the a ...
Lecture 16 Quantitative Genetics III and The Consequences of Small
... In: R. B. Primack. 1998. Essentials of Conservation Biology. Sinauer ...
... In: R. B. Primack. 1998. Essentials of Conservation Biology. Sinauer ...
Lecture 17 Quantitative Genetics III and The Consequences of Small
... In: R. B. Primack. 1998. Essentials of Conservation Biology. Sinauer ...
... In: R. B. Primack. 1998. Essentials of Conservation Biology. Sinauer ...
Population genetics is based on statistical models: “A model is an
... Note that Nes > 1 does not guarantee that an allele is going to be fixed, it simply indicates that (as a long term average) the frequency that it is fixed will be greater than the frequency under genetic drift alone. ...
... Note that Nes > 1 does not guarantee that an allele is going to be fixed, it simply indicates that (as a long term average) the frequency that it is fixed will be greater than the frequency under genetic drift alone. ...
(2 pts). - nslc.wustl.edu
... The chi-square is significant at the 5% level, so we reject neutrality (1 pt). There is an excess of nonsynonymous substitutions over synonymous in the old (evolutionarily successful) part of the tree, implying that selection is positive and favors amino acid changes in this protein (2 pts). c. Test ...
... The chi-square is significant at the 5% level, so we reject neutrality (1 pt). There is an excess of nonsynonymous substitutions over synonymous in the old (evolutionarily successful) part of the tree, implying that selection is positive and favors amino acid changes in this protein (2 pts). c. Test ...
Natural Selection And The Peppered Moth
... All living things “inherit” traits from their parents. In humans, a trait can be hair color and how tall we are (height), just to name a couple. In birds it can be the color of its feathers, the shape of its beak or the strength of its song. In insects it can be body color or wing shape. If one (or ...
... All living things “inherit” traits from their parents. In humans, a trait can be hair color and how tall we are (height), just to name a couple. In birds it can be the color of its feathers, the shape of its beak or the strength of its song. In insects it can be body color or wing shape. If one (or ...
File - Ms. Richards IB Biology HL
... gene pool that is reproductively isolated from other species. Some populations of the same species are geographically isolated so it is possible for multiple gene pools to exist for the same species. Individuals that reproduce contribute to the gene pool of the next generation. Evolution is defined ...
... gene pool that is reproductively isolated from other species. Some populations of the same species are geographically isolated so it is possible for multiple gene pools to exist for the same species. Individuals that reproduce contribute to the gene pool of the next generation. Evolution is defined ...
Group selection
Group selection is a proposed mechanism of evolution in which natural selection is imagined to act at the level of the group, instead of at the more conventional level of the individual.Early authors such as V. C. Wynne-Edwards and Konrad Lorenz argued that the behavior of animals could affect their survival and reproduction as groups.From the mid 1960s, evolutionary biologists such as John Maynard Smith argued that natural selection acted primarily at the level of the individual. They argued on the basis of mathematical models that individuals would not altruistically sacrifice fitness for the sake of a group. They persuaded the majority of biologists that group selection did not occur, other than in special situations such as the haplodiploid social insects like honeybees (in the Hymenoptera), where kin selection was possible.In 1994 David Sloan Wilson and Elliott Sober argued for multi-level selection, including group selection, on the grounds that groups, like individuals, could compete. In 2010 three authors including E. O. Wilson, known for his work on ants, again revisited the arguments for group selection, provoking a strong rebuttal from a large group of evolutionary biologists. As of yet, there is no clear consensus among biologists regarding the importance of group selection.