BIOL 1408 - TOPIC 9

Natural selection was independently discovered by who? a) Charles Darwin b) Alfred Wallace c) Both Darwin and Wallace d) Neither Darwin or Wallace

a) Charles Darwin

The arctic hare and the arctic fox are not closely related and yet they are both white. This is an example of: a) convergent evolution b) divergent evolution c) homogeneous evolution d) alternate evolution

a) convergent evolution

Biological evolution: a) is defined as, "A change in gene frequencies over time". b) is defined as, "No change in gene frequencies over time". c) is impossible to study . d) was invented by Charles Darwin.

a) is defined as, "A change in gene frequencies over time".

Galápagos medium ground finches are found on Santa Cruz and San Cristóbal islands, which are separated by about 100 km of ocean. Occasionally, individuals from either island fly to the other island to stay. This can alter the allele frequencies of the population through which of the following mechanisms? a) natural selection b) genetic drift c) gene flow d) mutation

a) natural selection

Which of the following is not necessary for natural selection to occur? a) The characteristics of organisms must be heritable or passed from parent to offspring. b) Offspring must have variation of heritable characteristics. c) More offspring must be produced than are able to survive. d) Some offspring must individually evolve to their surroundings.

c) More offspring must be produced than are able to survive.

The wing of a bird and the arm of a human are examples of ____ . a) vestigial structures b) molecular structures c) homologous structures d) analogous structures

c) homologous structures

The fact that DNA sequences are more similar in more closely related organisms is evidence of what? a) optimal design in organisms b) adaptation and therefor similarity c) mutations or changes in the DNA code d) descent with modification or common ancestry

d) descent with modification or common ancestry

Why is gene flow important in evolution?:

- Gene flow can be an important source of genetic variation when unique genetic information from one population is introduced to another.

Define "species.":

- a group of actually or potentially interbreeding individuals

What are mutations?:

-Mutations are heritable changes in genetic information. Mutations are a source of new alleles in a population. Mutation is a change in the DNA sequence of the gene. A mutation can change one allele into another, but the net effect is a change in frequency.