Species & Speciation Chapter 22

Question 1

species are ____ from other species

Answer 1

reproductively isolated

Question 2

species are a ___ gene pool

Answer 2

closed

Question 3

what does the biological species concept say?

Answer 3

species are groups of interbreeding organisms that are reproductively separated from one another

Question 4

why does reproductive compatibility mean more than just making babies?

Answer 4

because it also has to do with making babies who can also have babies

Question 5

____ still counts as reproductive isolation

Answer 5

geographical separation

Question 6

which is the better concept to use and why?

Answer 6

morphospecies because it holds that members of the same species look alike-also extended to similar DNA sequences

Question 7

___ discredit the morphospecies concept

Answer 7

polymorphisms

Question 8

some species meet ___ criteria and not ___

Answer 8

biological species concept; morphospecies concept

Question 9

what are cryptic species?

Answer 9

organisms that people thought were 1 species but in reality are 2

Question 10

what are some problems with the BSC?

Answer 10

• doesn’t apply to asexual or extinct species

- ring species & hybridization complicate it

Question 11

ring species

Answer 11

populations that are reproductively but not genetically isolated

Question 12

how does ring species occur?

Answer 12

gene flow through intermediate populations

Question 13

hybridization

Answer 13

interbreeding

Question 14

why does hybridization complicate the BSC?

Answer 14

because these different forms should be considered one large species bc they are able to reproduce and produce fertile offspring but bc they maintain their distinct appearances, natural selection works against the hybrid offspring

Question 15

what is the evolutionary species concept?

Answer 15

different species means having different nutritional needs

Question 16

what is the phylogenetic species concept?

Answer 16

requires that all members of a species are descended from a single common ancestor. but it’s limited

Question 17

why are the ESC and PSC used?

Answer 17

to broaden the BSC concept

Question 18

what are pre-zygotic isolating factors?

Answer 18

prevent fertilization from taking place

Question 19

what are post-zygotic isolating factors?

Answer 19

when fertilized egg develops into fertile organism

Question 20

behavioral isolation is a type of

Answer 20

pre-zygotic factor

involves specific courtship rituals, songs, etc.

Question 21

gametic isolation is a type of

Answer 21

pre-zygotic factor

2 different species can’t mate/cross because they’re incompatible

Question 22

what is mechanical incompatibility?

Answer 22

pre-zygotic factor

repro parts don’t fit outside of species

Question 23

temporal isolation is a type of

Answer 23

pre-zygotic factor

plants/animals don’t come in contact with one another b/c reproduce @ different points in the year

Question 24

geographic/ecological isolation is a type of

Answer 24

pre-zygotic factor

2 species don’t mate b/c they’re not physically located near one another

Question 25

post-zygotic isolating factors usually involve

Answer 25

genetic incompatibility

Question 26

the more ___ a pair of species, the ____ the genetic incompatibility between their genomes

Answer 26

closely related; less extreme

Question 27

speciation is a by-product of

Answer 27

genetic divergence of separated populations

Question 28

genetic divergence

Answer 28

occurs over time & causes diff. populations to become reproductively isolated (results in speciation)

Question 29

partial reproductive isolation

Answer 29

happens when members of different populations aren't separate species yet but enough that when crossed, their kids have decreased viability/fertility

Question 30

allopatric speciation

Answer 30

speciation that results from geographical separation of populations

Question 31

speciation not only requires __ but ___

Answer 31

separation; time

Question 32

subspecies

Answer 32

when pops haven't yet achieved speciation, but have pop. specific traits

Question 33

how do populations become allopatric?

Answer 33

dispersal & vicariance

Question 34

dispersal

Answer 34

when orgs colonize distance place-away from main pop

Question 35

vicariance

Answer 35

geographic barrier comes about w/n a single pop which separates it into 2 or more isolated pops -easier to study

Question 36

allopatric populations always

Answer 36

lead to speciation

Question 37

dispersal is a kind of __

Answer 37

peripatric speciation b/c orgs from mainland pop. disperse on purpose or get separated from mainland pop. by accident making their own "island population"

Question 38

why is change faster in peripatric speciation?

Answer 38

b/c island pops. are smaller & more susceptible to drift & b/c environment different so genetic divergence goes up & speciation occurs

Question 39

adaptive radiation

Answer 39

rapid evolution which accelerates speciation & adaptation

Question 40

how does adaptive radiation come about?

Answer 40

ecological opportunity & potential for allopatric speciation

Question 41

what is co-speciation?

Answer 41

speciation that occurs in response to speciation in another species

Question 42

separation can occur without

Answer 42

actual geographic barriers

Question 43

how did malaria come to infect humans?

Answer 43

plasmodium population with chimps could've been subject to co-speciation

Question 44

sympatric populations

Answer 44

those not geographically separated - may undergo speciation - natural selection can explain it

Question 45

why do split populations get more & more different?

Answer 45

mutations that eventually become fixed

Question 46

gene flow inhibits

Answer 46

genetic divergence

Question 47

we don't know how much of speciation is ___ or ___

Answer 47

sympatric; allopatric

Question 48

instantaneous speciation

Answer 48

when speciation occurs quickly - is sympatric - caused by hybridization

Question 49

plants can form new species through

Answer 49

polyploidy

Question 50

what has been pivotal to the evolution of plants?

Answer 50

genome-doubling

Question 51

speciation can occur without

Answer 51

natural selection | -can be entirely due to genetic drift

Question 52

natural selection is involved in which kinds of speciation?

Answer 52

allopatric & sympatric

Question 53

natural selection can enhance

Answer 53

reproductive isolation