Penn Foster Biology Evolution Exam Review |
Chapters 14–19 Explained
Evolution
Genetic change in a line of descent over time.
Fossils
Impressions, or casts, in sedimentary rocks of long deceased organisms.
Biogeography
Te study of the distribution of organisims throughout the world.
Summarize how nineteenth-century scientists contributed to the study of evolutionary change.
The work of Charles Darwin helped shape modern evolutionary thought. All species on Earth,
including humans, have a common ancestry due to the process of evolution. Scientific evidence
strongly supports evolutionary theory.
Explain how Darwin's study of fossils and biogeography contributed to the development of the
theory of natural selection.
Darwin concluded that related organisms have common ancestors. As adaptive characteristics
become more widespread in a population through successive generations, the result is natural
selection
Describe the steps in the theory of natural selection.
1. the members of a population have heritable variations
2. the population produces more offspring than the resources of an environment can support
3. the individuals that have favorable traits survive and reproduce to a greater extent than those
that lack these traits
4. across generations, a larger proportion of the population possesses the favorable traits and
the population becomes adapted to the environment
Distinguish between natural and artificial selection.
natural selection is survival of the fittest, and artificial selection is breeding out particular traits.
Explain how the fossil record, biogeographical evidence, comparative anatomy, and
biochemistry support evolutionary theory.
, 1. fossil record provides information about ancestors and transitional forms between ancestors
and organisms which exist today.
2 .The study of the distribution of organisms across the earth provides evidence for evolution
3. The study of vestigial structures, homologous and analogous structures, as well as
developmental patterns among related groups of organisms, provides evidence for evolution.
4. The presence of similar biochemical molecules including DNA, ATP, and cytochrome C provide
evidence for evolution. In addition, gene and amino acid sequence similarities provide further
evidence for evolution from a common ancestor
Review briefly Darwin and what he determined from the finches.
Darwin was a naturalist aboard the HMS Beagle on their 5-year voyage. Charles noticed that
each species has the same ancestor but they evolve to adapt over time so they can live longer.
Directional Selection
extreme phenotype is favored
Stabilizing Selection
extreme phenotypes are selected against
Disruptive Selection
Two or more extreme phenotypes are favored over the average ones.
Explain how heterozygotes maintain variation in a population, and summarize the concept of a
heterozygote advantage.
Heterozygotes have greater reproductive success than homozygotes, leading to the
maintenance of two alleles in the population.
Microevolution
evolution on its smallest scale, defined as a change in the relative frequencies of alleles in a
population over a number of generations
Understand how the Hardy-Weinberg principle is used to explain the process of microevolution.
It states that the unchanging frequency of alleles and genotypes in a stable, idealized
population. In this population we assume there is random mating and sexual reproduction
without normal evolutionary forces such as mutation, natural selection, or genetic drift.
Describe how mutations, gene flow, nonrandom mating, genetic drift, and natural selection can
cause changes in the frequency of an allele in a population.
Chapters 14–19 Explained
Evolution
Genetic change in a line of descent over time.
Fossils
Impressions, or casts, in sedimentary rocks of long deceased organisms.
Biogeography
Te study of the distribution of organisims throughout the world.
Summarize how nineteenth-century scientists contributed to the study of evolutionary change.
The work of Charles Darwin helped shape modern evolutionary thought. All species on Earth,
including humans, have a common ancestry due to the process of evolution. Scientific evidence
strongly supports evolutionary theory.
Explain how Darwin's study of fossils and biogeography contributed to the development of the
theory of natural selection.
Darwin concluded that related organisms have common ancestors. As adaptive characteristics
become more widespread in a population through successive generations, the result is natural
selection
Describe the steps in the theory of natural selection.
1. the members of a population have heritable variations
2. the population produces more offspring than the resources of an environment can support
3. the individuals that have favorable traits survive and reproduce to a greater extent than those
that lack these traits
4. across generations, a larger proportion of the population possesses the favorable traits and
the population becomes adapted to the environment
Distinguish between natural and artificial selection.
natural selection is survival of the fittest, and artificial selection is breeding out particular traits.
Explain how the fossil record, biogeographical evidence, comparative anatomy, and
biochemistry support evolutionary theory.
, 1. fossil record provides information about ancestors and transitional forms between ancestors
and organisms which exist today.
2 .The study of the distribution of organisms across the earth provides evidence for evolution
3. The study of vestigial structures, homologous and analogous structures, as well as
developmental patterns among related groups of organisms, provides evidence for evolution.
4. The presence of similar biochemical molecules including DNA, ATP, and cytochrome C provide
evidence for evolution. In addition, gene and amino acid sequence similarities provide further
evidence for evolution from a common ancestor
Review briefly Darwin and what he determined from the finches.
Darwin was a naturalist aboard the HMS Beagle on their 5-year voyage. Charles noticed that
each species has the same ancestor but they evolve to adapt over time so they can live longer.
Directional Selection
extreme phenotype is favored
Stabilizing Selection
extreme phenotypes are selected against
Disruptive Selection
Two or more extreme phenotypes are favored over the average ones.
Explain how heterozygotes maintain variation in a population, and summarize the concept of a
heterozygote advantage.
Heterozygotes have greater reproductive success than homozygotes, leading to the
maintenance of two alleles in the population.
Microevolution
evolution on its smallest scale, defined as a change in the relative frequencies of alleles in a
population over a number of generations
Understand how the Hardy-Weinberg principle is used to explain the process of microevolution.
It states that the unchanging frequency of alleles and genotypes in a stable, idealized
population. In this population we assume there is random mating and sexual reproduction
without normal evolutionary forces such as mutation, natural selection, or genetic drift.
Describe how mutations, gene flow, nonrandom mating, genetic drift, and natural selection can
cause changes in the frequency of an allele in a population.
