Term test Ch. 21

Question 1

What is the biological species concept

Answer 1

Species are defined if they can reproduce with fertile offspring

Question 2

What is the shortcoming of the biological species concept

Answer 2

It’s difficult to apply, it’s not practical to force two species to mate and determine if offspring is fertile

Question 3

What is the morphological species concept

Answer 3

Species are defined if they look alike, or on the molecular level has similar DNA sequences

Question 4

What is the shortcoming of the morphological species concept

Answer 4

Many species that look the same may be different and male species can differ from females

Question 5

Cryptic species

Answer 5

Species that consist of organisms that were considered as one species but are different at the DNA sequence level

Question 6

Ecological species concept

Answer 6

one to one correspondence between species and niche

Question 7

Phylogenetic species concept

Answer 7

members of a species all share a common ancestor and common fate

Question 8

Prezygotic factors

Answer 8

factors that act before an egg is fertilized

Question 9

Postzygotic factors

Answer 9

factors that act after an egg is fertilized

Question 10

Behaviourally isolated

Answer 10

individuals mate only with other individuals based on behaviors

Question 11

Gametic isolation

Answer 11

Incompatibilities between gametes of two species

Question 12

Mechanical incompatibility

Answer 12

Things such as genitalia not fitting

Question 13

Temporal isolation

Answer 13

Isolated by time

Question 14

Geographic/ecological isolation

Answer 14

Physically isolated in space

Question 15

Genetic incompatibility

Answer 15

Chromosomal incompatibility

Question 16

Speciation

Answer 16

A by-product of genetic divergence when the fixation of different mutations in populations that aren’t regularly exchanging genes

Question 17

Partially reproductively isolated

Answer 17

Not truly separate species, but the genetic differences between them are extensive enough that the hybrid offspring they produce have reduced fertility or viability

Question 18

Allopatric

Answer 18

Geographic separation between two populations

Question 19

Dispersal

Answer 19

Individuals colonize a distant place, such as an island, far from the main source population

Question 20

Vicariance

Answer 20

Geographic barrier arises within a single population, separating it into two or more isolated populations

Question 21

Peripatric speciation

Answer 21

A specific kind of allopatric speciation in which a few individuals from a mainland population disperse to a new location

Question 22

Adaptive radiation

Answer 22

Speciation occurs rapidly to generate variety and ecologically diverse forms, best documented on an oceanic island following the arrival of single ancestral species

Question 23

Co-speciation

Answer 23

Process in which two groups of organisms speciate in response to each other and at the same time

Question 24

Sympatric

Answer 24

No geographic separation between diverging populations but still speciation occurs

Question 25

Instantaneous speciation

Answer 25

Speciation in one generation