Science Test - Darwin

what are examples of evidence for evolution?

- fossil records - DNA comparisons - homoglobous structures - comparitive and bioligy - vestigil structures

Variation

Any difference between individuals of the same species.

natural selection

Working on existing variation of traits to factor those better suited to the organisms environment.

genetic variation

a measure of how much individuals in a population differ genetically

reproductive isolation

a species of squirrels divides into two groups because of changes from an earthquake.

Evolution by natural selection

how a population can change in response to its environment.

Environmental factors

it determines favorable and unfavorable traits in a population and its conditions in a place that affects organisms that live there.

What is comparitive anatimy?

it is the branch of biology that compares the similarities and differences of living things.

what are the 2 theories of evolution?

one is all living things are realated and evolution is powered by natural processes.

What actually evolves?

population

speciation

the forming of a new species by evolution

What are homologous structures?

they are bones that seem to have the same set up in very different creatures.

What is a vestigial structure?

they are leftover parts or stuctures that a animal has but does not use.

did all living things come from a common ancester?

yes

seperation

Over time, separated bird groups change so they eat different kinds of seeds.

A population of grasshoppers in the Kansas prairie has two color phenotypes, green and brown. Typically the prairie receives adequate water to maintain healthy green grass. Assume a bird that eats grasshoppers moves into the prairie. How will this affect the natural selection of grasshoppers?

The brown phenotype should be more easily seen but the predator and decrease in frequency.

how many species are alive today?

8.7 million

Mutation

A change in a gene

what will happen if a species cannot adapt to changes?

The species may become extinct

What is embryology?

It is a study of how an organism develops before being born or hatching from an egg

how is DNA used for evolution?

Scientists can compare DNA structures to show who is related to who.