SAT Bio II: Evolution


Change in genes of a population over time


Evolution that refers to changes in one gene pool of a population over generations


Evolution that refers to speciation*, the formation of an entirely new species.


True or false: individuals never change or evolve. A population is the smallest group that can evolve.


What is the smallest group that can evolve?


Consists of all the members of one species in one place

Fossil record

Evidence of evolution that reveals the existence of species that have become extinct or evolved into other species.

Transitional fossils

Fossils that link older extinct fossils to modern species

Comparative anatomy

Evidence of evolution that shows similar anatomical structures are related to eachother and share a common ancestor.


Organisms with similar structures but different functions. Indicates common ancestry and divergent evolution.


What kind of organisms are an example of divergent evolution?


Organisms with similar function but different structure. Indicate no common ancestry and convergent evolution.


What kind of organisms are an example of convergent evolution?

No, yes

Do analogous organisms indicate common ancestors? Homologous?


Structures such the appendix. Evidence that the anatomy of animals have evolved.


The geographic distribution of species. Evidence of evolution.
ex. Marsupials migrated from Pangaea and now are isolated in Australia


Theories relied on inheritance of acquired traits and use and disuse (disproven)

Source of variation

What could Darwin not explain in his theory of natural selection?

de Vries

Discovered mutations are the source of variation

Peppered moths

Industrialization gave the dark variety of these organisms a selective advantage and vice versa for the light variety. (directional isolation)

Industrial melanism

Darkening due to industrialization (peppered moths)

No (bacterial can resist antibiotics in a number of months)

Does all evolution occur slowly?


Type of natural selection that eliminates the number of extremes and favors the more common intermediate forms.


What type of natural selection is keeping the majority of birth weight between 6 and 9 pounds to eliminate the larger/smaller?


What's another word for diversifying selection?


Selection that increases the number of extreme types in a population and the expense of the intermediate forms. Results in a balanced polymorphism, and formation of two new species.

Extreme, intermediate

Diversifying/disruptive selection increases the number of _____ types in a population and the expense of the ______ forms.

Balanced polymorphism

When two or more phenotypes exist in a population. Result of diversifying selection.

Diversifying/disruptive selection

What is balanced polymorphism associated with?

Blanced polymorphism, and formation of two new species

What are the 2 results of diversifying/disruptive selection?


Natural selection where one phenotype replaces another in the gene pool.


What type of natural selection are peppered moths an example of?

Changing environment

What is the cause of directional selection?

Bottleneck and founder effect

What are 2 types of genetic drift?

Mutation, genetic drift, gene flow

What are 3 sources of variation in a population?

Genetic drift

Source of variation. Change in gene pool due to chance.


Genetic drift is a source of variation and change in gene pool due to ______.

Bottleneck effect

Type of genetic drift where natural disasters such as fire, earthquake, and flood reduce population size non selectively, resulting in loss of genetic variation. Certain alleles may be under or overrepresented compared with the original population.

Natural disasters

What is the cause of the bottleneck effect?

Non selective

Is the bottleneck effect selective or nonselective?

Founder effect

Type of genetic drift where a small population non genetically representative of the larger population breaks away to colonize a new area. Rare alleles may be overrepresented.
ex. Amish have extra toes/fingers

Gene flow

Source of variation. Movement of alleles into or out of a population. Can occur as a result of migration of fertile individuals or gametes between populations.


According to the Hardy-Weinberg Equilibrium, must population size be very small or very large?


According to the Hardy-Weinberg Equilibrium, must the population be isolated? (no migration of organisms into or out of the gene pool)


According to the Hardy-Weinberg Equilibrium, can there be mutations in the stable population?


According to the Hardy-Weinberg Equilibrium, must mating in the population be selective or random?


According to the Hardy-Weinberg Equilibrium, can there be natural selection in the population?


In the Hardy-Weinberg Equation, does p or q stand for dominant allele?


In the Hardy-Weinberg Equation, does p or q stand for recessive allele?

Homozygous dominant

In the Hardy-Weinberg Equation, what individual does p� represent?

Homozygous recessive

In the Hardy-Weinberg Equation, what individual does q� represent?

p + q = 1
p� + 2pq + q� = 1

What are the 2 Hardy-Weinberg Equations?


What represents the hybrid condition in the Hardy-Weinberg Equation?


What individual does 2pq represent in the Hardy-Weinberg Equation?

Geographic isolation

Occurs when species are separated by mountain ranges, canyons, rivers, lakes, glaciers, etc. Cannot reproduce after separation.


Is polyploidy a type of isolation?


Mutation that results from errors during meiosis. Organisms have a whole new set of chromosomes. Cannot breed with other organisms and are therefore isolated from them.

Habitat isolation

Occurs when two organisms live in the same area but encounter eachother rarely. Cannot reproduce.
ex. Snakes who live in water vs. on land

Behavioral isolation

Occurs when two animals become isolated from each other because of some change in behavior by one member or group.

Temporal isolation

Occurs when different plants of one species living in one area become functionally separated into two populations because some plants become sexually mature earlier and begin to flower in the cooler part of the season while other plants flower in the late

Reproductive isolation

Closely related species may be unable to mate because of anatomical incompatibility.


Evolution that occurs when a population becomes isolated from the rest of the species and becomes exposed to selective pressures, causing it to evolve into a new species.


What type of evolution do a whale and fish represent?


Evolution that occurs when unrelated species occupy the same environment and are subjected to similar selective pressures and show similar adaptations.


Evolution that occurs when two related species make similar evolutionary adaptations after their divergence from a common ancestor.


Do those who go through parallel evolution share a common ancestor?

Similar, divergence

In parallel evolution, related species make ____ evolutionary adaptations have their _____ from a common ancestor.


Mutual evolutionary set of adaptations of 2 interacting species.
ex. pollinator-plant relationships


What type of evolution do pollinator-plant relationships exhibit?

Adaptive radiation

Emergence of numerous species from a single common ancestor introduced into an environment
ex. Darwin's finches


Theory that organisms descend from a common ancestor gradually, over a long period of time, in a linear or branching* fashion. Has been disproved because says fossils should have no missing links.

Gould and Eldridge

Who developed the punctuated equilibrium theory?

Punctuated equilibrium

What did Gould and Eldridge develop?

Punctuated equilibrium

Proposes new species arise suddenly after long periods of no change. A new species arises in a different place and expands its range, competing with and replacing the ancestral species that becomes extinct. Developed by Gould and Eldridge.

Spontaneous generation

Theory that living things emerge from nonliving or inanimate objects. Disapproved.


Was there free oxygen in Earth's early atmosphere?

Heterotroph hypothesis

States first cells on earth were anaerobic heterotrophic prokaryotes

Anaerobic heterotrophs

The first cells on earth were aerobic/anaerobic autotrophic/heterotrophic.

No, no

Does evolution always cause organisms to become more complex? Does it always occur at the same rate?