Exam II - Chapter 13

Question 1

What is meant by secondary contact?

Answer 1

interbreeding of 2 formally allopatric populations that have become genetically differentiated

Question 2

what is reinforcement?

Answer 2

increase of reproductive isolation between populations through the selection against hybrid offspring

Question 3

pre-zygotic isolation and 4 examples

Answer 3

divergence in traits between populations that prevents fertilization 1. mechanical isolation - “lock & key”: physically can’t mate2. behavioral isolation - different mating calls/dances3. temporal isolation- breed at different times of year4. gamete incompatibility

Question 4

post-zygotic isolation and 2 examples

Answer 4

hybrid offspring that are sterile/infertile 1. zygote inviability 2. hybrid sterility - horse x donkey = sterile mule

Question 5

connected series of populations that have diverged sufficiently across their ranges so that the population at ends of series are too different to interbreed

Answer 5

ring species

Question 6

populations that live nearby are genetically more similar to each other than populations that live farther apart

Answer 6

isolation by distance

Question 7

when does hybridization result in either reinforcement or speciation? –not completely sure about this question

Answer 7

reinforcement: when hybrids are sterilespeciation: when hybrids are fertile

Question 8

speciation that occurs when populations are in separate, non-overlapping geographic areas- they are separated by geographic barriers. They are unlike;y to breed even if given the chance.

Answer 8

allopatric speciation

Question 9

Speciation that occurs when populations are in same geographic area - differences in phenotypes decrease the likelihood of interbreeding between populations

Answer 9

sympatric speciation

Question 10

2 types of physical isolation (allopatric speciation)

Answer 10

1. dispersal 2. vicariance - barrier is created

Question 11

2 types of mutational isolation (sympatric speciation)

Answer 11

1. genome duplication - results in polyploidy 2. polyploidy - causes instance reproductive isolation without physical isolation

Question 12

evolutionary process by which new species arise; causes 1 evolutionary lineage to split into 2 or more

Answer 12

speciation

Question 13

species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups

Answer 13

biological species concept

Question 14

species designation and identification based on morphological differences between populations; how fossils are assigned to species

Answer 14

morphospecies concept

Question 15

species are the smallest possible groups whose members are descended from a common ancestor and who all posses defining or derived characteristics that distinguish them from other such groups; they are the “tips” of phylogenetic trees

Answer 15

phylogenetic species concept

Question 16

consists of interbreeding populations that evolve independently of other species; smallest evolutionary individual unit

Answer 16

species