Chapter 16: Microevolution and Speciation

Question 1

___ is the geographic distribution of extant and extinct species.

Answer 1

Biogeography.

Question 2

What must occur during a period of geographic isolation in order for two sibling species to remain genetically distinct following their geographic reunion in the same home range?

Answer 2

Reproductive isolation

Question 3

Pre-zygotic barriers ___.

Answer 3

Prevent fertilization of gametes from members of sibling species.

Question 4

According to the Biological Species Concept, what is the most important feature distinguishing (separating) a species?

Answer 4

Ability to interbreed and produce fertile offspring.

Question 5

Which post-zygotic reproductive isolating mechanism occurs because first generation hybrids cannot produce offspring?

Answer 5

Hybrid sterility.

Question 6

True or false; the Hardy-Weinberg equilibrium is an example of an isolating mechanism.

Answer 6

False.

Question 7

Blue-footed boobies of the galapagos will mate only after a very specific courtship display on the part of the male. The male high-steps to advertise his bright blue feet. What isolating mechanism discourages mating outside the species?

Answer 7

Behavioral isolating.

Question 8

___ occurs from gradual changes that transform a species into a new species where ___ is the splitting of a species into two or more species.

Answer 8

Anagenisis / clatogenisis.

Question 9

How is sympatric speciation different from allopatric speciation? Give examples of each.

Answer 9

• Allopatric means “separate area.” An example of allopatric speciation would be antelope squirrels.
• Sympatric speciation requires ecological, genetic, or behavioral isolation (but not geographical) followed by reproductive isolation. An example of this is the Blue-Footed Boobie.

Question 10

What are the three domains of life? Give one feature of each.

Answer 10

Bacteria (unicellular)
Archea (extreme climates)
Eukarya (multi-cellular)