Unit 2 - Speciation

Question 1

Speciation

Answer 1

process by which one species splits into two or more

Question 2

Taxonomists

Answer 2

(those who define, name groups of
organisms) use morphology, physiology, genetics, behavior to define species

Question 3

Phylogenetic Species Concept

Answer 3

smallest group of individuals that share common ancestor; uses morphological characters, DNA

Question 4

Biological Species Concept

Answer 4

species are reproductively isolated from each other; different species cannot inter-breed and produce viable, fertile offspring

Question 5

Allopatric Speciation

Answer 5

subpopulations become geographically isolated from each other

Question 6

Sympatric Speciation

Answer 6

subpopulations in same geographic area become reproductively isolated

Question 7

Habitat Differentiation

Answer 7

subpopulations begin to exploit different habitats and/or resources

Question 8

Sexual Selection

Answer 8

preference for certain traits can disrupt gene flow, especially when reinforced by assortative mating

Question 9

Reproductive Isolating Mechanisms

Answer 9

barriers to gene flow between populations of different species are required to prevent hybrids from forming

Question 10

Punctuated Equilibria

Answer 10

periods of apparent stasis punctuated by sudden change

Question 11

Gradualism

Answer 11

Often species exhibit gradual pattern of change over time

Question 12

Mass Extinctions

Answer 12

more than 50% of world’s species become extinct; 5 in last 500 mil. years

Question 13

Cretaceous Extinction

Answer 13

over half marine species, all non-avian dinosaurs extinct; afterwards flowering plants appear, diversify, many new mammal species appear

Question 14

Adaptive Radiation

Answer 14

evolutionary change in which empty niches filled by new species