SPECIATION

Question 1

Specere

Answer 1

“Kind”
“Appearance”

Question 2

Modern classification system

Answer 2

Evolutionary history

Morphological and genetic characteristics

Its relatedness to other organisms

Question 3

Organisms evolving independently and distinctly from other groups

Answer 3

Species

Question 4

Scientists that built upon Darwin’s understanding of species by establishing INTERBREEDING as criteria (2)

Answer 4

Theodosius Dobzhansky
Ernst Mayr

Question 5

When was Darwin’s origin of species?

Answer 5

1859

Question 6

A group of individuals capable of mating and producing fertile offspring

Answer 6

Species

Question 7

Species factors (2)

Answer 7

Individuals interbreed and produce fertile offspring only among themselves

members of each species resemble each other and are structurally different from other species

Question 8

T or F: change in gene frequency constitutes speciation

Answer 8

False: It is considered evidence of evolution but does not constitute speciation

Question 9

Concept that states” A species is a population or group of populations that are able to INTERBREED, under NATURAL CONDITIONS, to produce FERTILE OFFSPRING

Does not apply to all life forms*

Answer 9

Biological species concept

Question 10

Process by which an ancestral species splits into 2 or more new species.

New species develop unique characteristics

Answer 10

Speciation

Question 11

Three main stages of speciation

Answer 11

Separation - original species split into two or more groups w/ no interbreeding and cut gene flow

Divergence - independent accumulation of heritable mutations and reproduction of individuals upon heritable traits

Isolation - maintained when groups reunite and unable to breed and produce viable offspring

Question 12

Types of isolation (2)

Answer 12

Premating isolation

Postmating Isolation

Question 13

Types of Natural Speciation (4)

Answer 13

Allopatric speciation - result of physical separation

Peripatric speciation - subform of allopatric speciation very small

parapatric speciation -slow process by which populations separate by occupying different niches

Sympatric speciation - formation of new species from populations of original species that occupy the same geographical location

Question 14

Occurs when scientists separate members of the same species into populations that form distinct species from selective breeding

Answer 14

Artificial speciation

Question 15

Greek words for Allopatric speciation

Answer 15

other + fatherlands

Question 16

Steps of allopatric speciation: (4)

Answer 16

Geographic barrier physically separates populations of the original species

Populations accumulate heritable mutations and experience selective pressures

Two populations become increasingly divergent until reproductively incompatible

Speciation is complete when interbreeding with fertile offspring is no longer possible

Question 17

When small groups of individuals break off from the larger group and form a new species

one group is much smaller than the other

unique characteristics of the smaller groups are passed onto future generations

Answer 17

Peripatric speciation

Question 18

Spatially segregate habitats

Maintain a zone of contact and do not cease the exchange of genes completely

Adjacent populations evolve into distinct species while maintaining contact along a common border

Answer 18

Parapatric speciation

Question 19

Greek words for Sympatric speciation

Answer 19

Together + fatherlands

Question 20

Speciation that occurs in the same area

Answer 20

Sympatric speciation

Question 21

The fertilization of the egg produces a _____ and allows us to distinguish between _____ (before the fertilized egg) and _____ (after the fertilized egg)

Answer 21

zygote
prezygotic
post-zygotic

Question 22

Separation of different species to keep them from creating offspring by preventing the gametes from forming a zygote

Answer 22

Prezygotic

Question 23

Occurs after gametes have made a zygote through fertilizing the egg, isolates after

Answer 23

Postzygotic

Question 24

Prezygotic isolation mechanisms (5)

Answer 24

Spatial isolation - physical distance

Temporal isolation - reproductive timing

Mechanical isolation - lack of fit between sex organs

Gametic isolation - lack of compatibility of gametes

Behavioral isolation - mating rituals or behaviors