Major Patterns of Evolution

Question 1

What does adaptive radiation mean?

Answer 1

Rapid increase in # of species with a common ancestor, characterized by great ecological and morphological diversity

Question 2

What is Allopatric speciation

Answer 2

speciation that occurs when biological populations of the same species become isolated due to geographical changes or social changes

Question 3

What are benthic zones

Answer 3

Lowest ecological zone in a water body

Question 4

What are limnetic zones

Answer 4

The open and well lit area of a freestanding body of freshwater

Question 5

What is the biological species concept

Answer 5

Defies a species taxon as a group of organisms that can successfully interbreed and produce fertile offspring

Question 6

What is coevolution

Answer 6

The influence of closely associated species on each other in their evolution

Question 7

What is the founder effect

Answer 7

Reduced genetic diversity which results when a population is DESCENDED from a small # of colonizing ancestors

Question 8

What is the diastema

Answer 8

the gap from front teeth to back (herbivores)

Question 9

What are some characteristics of herbivores

Answer 9

long jaw, reach into things, keep eye level above ground level

Question 10

What are carnassials for

Answer 10

• cut and shear meat = more efficient consumption

Question 11

what is genetic drift

Answer 11

variation in genotype frequency in small populations because of CHANCE disappearance of particular genes

Question 12

What are mechanisms of genetic divergence

Answer 12

1. mutation
2. genetic drift
3. genetic flow
4. non random mating
5. natural selection

Question 13

What are reproductive isolating mechanisms

Answer 13

a collection of evolutionary mechanisms, behaviours, and psychological processes critical for speciation

Question 14

What is sympatric speciation

Answer 14

the splitting of an ancestral species into two or more reproductively isolated groups without geographical isolation

Question 15

What is dispersal

Answer 15

• few members of a species move to new area
• leads to allopatric speciation

Question 16

What is vicariance

Answer 16

separation of populations when physically split in two

Question 17

What are two ways to get allopatric speciation

Answer 17

vicariance and dispersal

Question 18

What are the three major types of predators snails face

Answer 18

1. chipping (crabs and lobsters)
2. Rasping predators (other snails and octopi)
3. biting predators (fish)

Question 19

What is a radula

Answer 19

for rasping predators, a rasping file like structure covered with tiny teeth… rasp through shell of prey to make a hole and suck the body out

Question 20

What adaptations from chipping predators

Answer 20

hidden lip
thicker lip

Question 21

What adaptations from rasping predators

Answer 21

• spikier mouth (can’t get close)
• ridges

Question 22

What adaptations from biting predators

Answer 22

• spikier mouth
• bigger
• extra smooth = sticks to ground and slippery, hard to grab
• thick

Question 23

What are characteristics of omnivores

Answer 23

1. flat cheek teeth
2. short canines
3. not self sharpening
4. not shearing cheek teeth
5. mostly enamel (white)

Question 24

What are characteristics of herbivores

Answer 24

• enamel worn off by grinding and exposes dentin
• sharp cheek teeth to break down cell wall
• gap /diastema = long jaw

Question 25

What are characteristics of carnivores

Answer 25

• covered enamel
• carnasial
• molars may be absent
• space between back teeth next to carnassial
• shearing teeth

Question 26

What is evolutionary arms race

Answer 26

predators evolved specialized weapons of attack and prey evolved specialized defences