NAME ______

Ch. 15 Study Guide-KEY

  1. Whatdid Charles Darwin personally observe about the finches while visiting the different

Galápagos Islands?

There were different finch species with different traits on each island, especially different beak sizes that were related to available food sources.

  1. What is the definition of adaptation? Give an example.

An adaptation is an inherited trait that makes an organism fit to live in its environment.

  1. What is the definition of evolution?

Change in a species over time, especially in its gene pool.

  1. What is the definition of homologous structures?

Structures with a similar structure, but a different function and thought to have descended from a common ancestor. For example, the wing of a bat and a human limb.

  1. What is the definition of analogous structures (convergence)?

Structures that are not evolved from a common ancestor, but that have a similar structure and function.

  1. What is the definition of vestigial structures?

Vestigial structures are structures that no longer have a function in an organism, but still exist.

  1. What is the definition of camouflage? Give an example.

It is when an organism blends into its environment and avoid predation like a sea dragon that looks like a plant.

  1. What is the definition of a bottleneck?

When a large amount of a population dies off and only a few members of the population are left to repopulate.

  1. Explain Darwin’s conclusion that he made regarding natural selection soon after returning from the Galapagos Islands?

Natural Selection is the way a species changes over time as a result of surviving in its environment.

  1. What is the founder effect?

When a small, separated population has a unique genetic make-up.

  1. What is the definition of allopatric speciation or geographic isolation?

When a population is separated by a geographic barrier such as a river or mountains.

  1. What is temporal isolation?

Populations reproduce at different times so they cannot mate together and share genes

  1. What is artificial selection?

Selective breeding of domestic animals or plants for desired traits.

  1. What is sexual selection?

Change in frequency of a trait based on competition for a mate.

  1. What do you call the study of structures of organisms during early stages of development?

embryology

  1. What is behavioral isolation?

Populations are separated by behavioral differences and don’t mate with each other to share genes

  1. What is meant by “common descent”?

Organisms of different species descend from a common ancestor.

  1. What is genetic equilibrium?

Allelic Frequencies remain the same

No evolution

Random mating

Large population

No immigration or emigration

No mutation

No natural selection

  1. What is mimicry?

An adaptation that allows one species to evolve to resemble another species for protection or other advantages.

  1. Explain how mimicry is a beneficial adaptation for the harmless species?

They can avoid predation.

  1. Study figure 2 below and identify the type of natural selection illustrated by the graph. (Directional, Stabilizing, Disruptive) Explain your answer.

Disruptive selection because the light and dark furred squirrels are being selected for.

  1. Explain what type of environments the light and dark colored moths would survive best in. Name some things that are causing the environment to change.

As pollution increases, the environment gets darker

due to soot. The Dark moths survive best in the

dark environments and the light moths survive better in a light environment.

  1. What type of graph is: Directional Selection
  2. GRAPH A ______
  1. GRAPH B ______Stabilizing Selection______
  1. GRAPH C ______Disruptive Selection______
  1. What is being selected against in:
  2. GRAPH A ______Small beaks______
  1. GRAPH B ______Large or Small Body Mass______
  1. GRAPH C ______Average Beak Size______