Biology- Evolution Test Study guide

How do fossils provide evidence for evolution?

They show transitional forms that show gradual change in fossil records over time.

What is a cladogram?

A diagram that presents hypothesis about how groups of organisms are related

What is natural selection?

An explanation for how evolution happens that is based on fitness

What are the requirements for natural selection?

Variability, Heritability, Reproductive advantage.

How did Hutton and Lyell influence Darwin?

They told him the earth was old.

How did Lamarck influence Darwin?

He told him that species could change traits over their lifetime and pass the acquired traits to their offspring.

How did Malthus influence Darwin?

He explained how populations grow faster than resources leading to competition for survival.

What is an adaptation?

A trait that increases fitness over time

What is fitness?

The measure of ability to reproduce and survive in an environment

What are the sources of genetic variation?

Crossing over, random fertilization, independent assortment, mutation, migrations

What is genetic drift?

When allele frequency changes due to a random chance.

What is the bottleneck affect?

When allele frequency changes due to a loss in population.

What is an example of the bottleneck affect?

Cheetahs, wildfires, beetles, elephant seals

What is the founder effect?

A form of genetic drift where a small group colonizes a new area

What is an example of the founder effect?

The finches when they moved to islands.

What is genetic equilibrium?

When allele frequencies stay constant and the same.

What are the conditions for genetic equilibrium?

random mating, no mutations, no migration, no natural selection, large population.

What does it mean when genetic equilibrium is disrupted?

Natural selection causes allele frequency to become uneven.

What are the 5 things that provide evidence for evolution?

Fossils, anatomy, DNA, Embryology, Direct observations

How do homologous structures provide evidence of evolution?

It can prove common ancestors of species and prove how they have changed over time.

What is an example of homologous structures?

Humans, whales, bats, cats. They all have same structures of bones but use them for different tasks.

What are analogous structures?

Structures that are used for the same purposed but are structurally different, suggesting they are not closely related.

What is an example of analogous structures?

Birds vs butterflies. This is because both the butterfly and bird have wings that allow them to fly but their wings look different and a butterfly is an insect.

How do vestigial structures provide evidence of evolution?

They are leftover body parts no longer in use which proves that they no longer have a function but were useful in ancestors.

What is an example of a vestigial structure?

Appendix

How does DNA provide evidence for evolution?

When the DNA of 2 species are compared, you can see the similarities between them, meaning they could be closely related.

How do embryos provide evidence for evolution?

Some embryos develop in similar patterns in different species, proving that they could be closely related.

What is a direct observation example of evolution?

Rock pocket mice, finches

What is directional selection?

When one extreme phenotype is favored

What is stabilizing selection?

When individuals with intermediate phenotypes have the most fitness

What is disruptive selection?

When both extreme phenotypes are favored

What is speciation?

The formation of a new species

What is a species?

A group of organisms that can interbreed and produce fertile offspring

What is allopatric speciation?

Groups that are separated by geography.

What is sympatric speciation?

Groups that inhabit the same area but isolate in different ways.

What is behavioral speciation?

Different behaviors prevent groups from interbreeding.

What is temporal speciation?

Species reproduce at different times.

What is reproductive isolation?

When 2 groups cannot mate and produce fertile offspring due to a barrier.

What is a derived character?

A trait shared by all its descendants.

What is a clade?

A group of species that includes a single common ancestor and all descendants of that ancestor

What is convergent evolution?

When unrelated organisms in a similar environment independently evolve similar characteristics.

What is adaptive radiation?

A single species evolves into several distinct species

What is the Hardy Weinberg principle?

A population's allele frequencies will stay the same over time if no forces are acting on it.

What is coevolution?

When 2 species evolve in response to changes in each other over time.

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