Exam II - Chapter 13 Flashcards Preview

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Flashcards in Exam II - Chapter 13 Deck (16):
1

What is meant by secondary contact?

interbreeding of 2 formally allopatric populations that have become genetically differentiated

2

what is reinforcement?

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

3

pre-zygotic isolation and 4 examples

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

4

post-zygotic isolation and 2 examples

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

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

ring species

6

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

isolation by distance

7

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

reinforcement: when hybrids are sterilespeciation: when hybrids are fertile

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.

allopatric speciation

9

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

sympatric speciation

10

2 types of physical isolation (allopatric speciation)

1. dispersal 2. vicariance - barrier is created

11

2 types of mutational isolation (sympatric speciation)

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

12

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

speciation

13

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

biological species concept

14

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

morphospecies concept

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

phylogenetic species concept

16

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

species