Evolution Test Study Guide Answers

• Adaptation– Process leading to the increase in frequency of a particular

structure, process, or behavior that makes the organism better able to survive and reproduce

• Natural selection– Changes in inherited traits of a population over time– Changes help to increase the species’ fitness in its environment

• Coevolution– Two species that live in close proximity changing in response to

changes in the other• Divergent evolution

– A number of species split off from a common ancestor• Convergent evolution

– Evolution in different groups of organisms living in similar environments that produces species that are similar in appearance and behavior

• Gene flow– Movement of genes in and out of a population (migration)

• Gradualism– Gradual changes of a species in a particular way over long

periods of time• Homologous structures

– Structures that have different mature forms but develop from the same embryonic tissues

• Analogous structure– Structures similar in appearance and function but with

different evolutionary origins• Embryology

– Study of the anatomy of embryos and their development• Phylogenetic tree

– Diagram used to show the evolutionary relationships between organisms and classify them into major taxa

• Where did Darwin draw his ideas of natural selection?– Galapagos Islands

• According to Darwin, evolution occurs because of what?– Because of natural selection

• What causes variations in genotypes?– Mutations

• Natural selection could not occur without genetic _variation_ in species.

• Who proposed the idea of inheritance of acquired characteristics?– Lamark

• What do scientists study when looking at biochemical similarities among organisms?– DNA sequences

• What would affect the evolution of a species over time?– Resources in the environment and the offspring

produced

• What would happen to the populations of the same species living in different areas?– They would evolve differently over time because

of their different environments• Give an example of divergent and convergent

evolution.– Divergent: beaks of finches on Galapagos Islands– Convergent: insect, bird, and bat wings

• What type of population is most susceptible to loss of genetic variability as a result of genetic drift?– Small populations

• Describe and give an example of geographic isolation.– When organisms are physically separated and form

different species over time because of that separation

– Butterfly species on the east coast and those on the west coast of the US

• List all the conditions of the Hardy-Weinberg equilibrium.– Large population with no genetic drift– No migration– Random mating– No mutations– No natural selection

• Explain reproductive isolation.– Organisms are able to mate but don’t because

they live in different areas of the same habitat or in the same habitat but can’t breed because of polyploidy

• Describe how speciation could occur as a result of geographic isolation.– One species gets separated into two groups by a

barrier. The two groups look different from each other due to different environments.

• What are the pieces of evidence for evolution?– Anatomy, embryology, biochemistry, paleontology

• What is a vestigial structure and give an example.– Structure that had an important function in an

ancestor species but no longer serves a function– Appendix in humans

• How do fossils demonstrate evidence of evolution?– Shows ancient species that are similar to modern

species• What is a transitional fossil?– A fossil of an intermediate stage in the evolution of

species• What do similarities in proteins of different

species indicate?– They share a common ancestor