Species and Speciation

Question 1

Phentic Species Concept

Answer 1

AKA morphological species concept, species grouped based on morphology
-Populations with extreme variations are separate species; Similar species are clustered together

Question 2

Biological Species Concept

Answer 2

Species grouped based on whether gene flow can occur between populations
-Naturally interbreeding populations
-Use pattern of gene flow to assign species boundaries

Question 3

Ecological Species Concept

Answer 3

Individuals or populations that complete closely and whose descendants can potentially replace one another
-Arrows represent direct ecological competition among individuals; Use extent of ecological competition to assign species boundaries

Question 4

Phylogenetic Species Concept

Answer 4

Individuals with the same derived traits (synapomorphy) are members of the same species

Question 5

Allopatric Speciation

Answer 5

Speciation that results from geographic isolation

Question 6

Allopatric Vicariance Speciation

Answer 6

Geographic barrier

Question 7

Allopatric Peripheral Speciation

Answer 7

Disperse to an isolated region (like Founder effect)

Question 8

Parapatric Speciation

Answer 8

Adjacent populations diverge into separate species because of a spatial gradient in genotypes or phenotypes (has hybrids)

Question 9

Ring Species

Answer 9

Individuals live in one of a series of populations that are connected to one another
-No breeding between some populations

Question 10

Sympatric Speciation

Answer 10

Divergence without a geographic barrier or spatial gradient
-Change in resource usage or change in reproduction

Question 11

Reproductive Character Displacement

Answer 11

Area of overlap characteristics are most different

Question 12

Pre-Zygotic Isolation

Answer 12

-Potential mates live in the same place but do not encounter one another, due to either: habitat isolation and/or temporal isolation (time of day or time of year)
-Potential mates interact or do not mate (behavioral isolation)
-Individuals copulate, but male gametes (sperm or pollen) are not transferred
-Male gametes are transferred, but the egg is not fertilized (gametic incompatibility)

Question 13

Post-Zygotic Isolation

Answer 13

-Zygote dies early in embryogenesis
-F1 hybrids are inviable
-F1 hybrids survive but are sterile
-Backcross or F2 hybrids are inviable or sterile

Question 14

Temporal Isolation

Answer 14

Occurs when two species mate at different times of year (or day)

Question 15

Behavioral Isolation

Answer 15

Occurs when two species have different courtship behaviors

Question 16

Gametic Isolation

Answer 16

Occurs when gametes (egg and sperm) come into contact, but no fertilization takes place

Question 17

Mechanical Isolation

Answer 17

Occurs when physical differences prevent copulation/pollination

Question 18

Habitat Isolation

Answer 18

Occurs when habitat preferences lower the probability of mating between individuals associated with differing habitats

Question 19

What are the four forms of post-zygotic isolation?

Answer 19

-Zygote dies early
-Offspring are infertile
-Offspring cannot survive (inviable)
-F2 hybrids are infertile or inviable