Topic 8: Speciation

Question 1

What is speciation?

Answer 1

Process where one ancestral species diverges into two + genetically distinct, reproductively isolated species

Question 2

What is macroevolution?

Answer 2

Broad patterns of evo change above species level

Question 3

What is the Biological Species Concept?

Answer 3

Identifies a species based on their potential to interbreed

Question 4

What is the Morphological Species Concept?

Answer 4

Identifies a species based on their physical appearance or structural traits

Question 5

What is the Ecological Species Concept?

Answer 5

Identifies a species based on its ecological niche

Question 6

What is the Phylogenetic Species Concept?

Answer 6

Defines a species as smallest group of indivs that share a common ancestor

Question 7

What are prezygotic barriers?

Answer 7

Barriers that occur before fertilization

Question 8

What are postzygotic barriers?

Answer 8

Barriers that occur after fertilization

Question 9

What are the five types of prezygotic barriers

Answer 9

1. Habitat isolation
2. Temporal isolation
3. Behavioural isolation
4. Gametic isolation
5. Mechanical isolation

Question 10

What is reduced hybrid viability?

Answer 10

Genes of diff parent species interact to impair hybrid’s development of survival

Question 11

What is reduced hybrid fertility?

Answer 11

Chromosomes of diff parent species differ in number or structure, meiosis fails (sterile)

Question 12

What is hybrid breakdown?

Answer 12

1st generation are vigourous and fertile, subsequent generations are feeble or sterile

Question 13

What is allopatric speciation?

Answer 13

Occurs when population is geographically separated into isolated groups

Question 14

What is sympatric speciation?

Answer 14

Occurs w/i the same geographic area and requires reproductive isolation

Question 15

What is vicariance?

Answer 15

Range of species is split by change in environment, creating two populations

Question 16

What is polyploidy speciation?

Answer 16

Process where new species arise from increase in number of chromosomal sets, reproductive isolation from parent population

Question 17

How do polyploids arise?

Answer 17

Hybridization of related species or chromosomal errors (autopolyploids)

Question 18

What is an allopolyploid?

Answer 18

Species w/ multiple sets of chromosomes, derived from the hybridization of diff species

Question 19

What is an autopolyploid?

Answer 19

Individual with more than
two chromosome sets, derived from one species

Question 20

What is sexual dimorphism?

Answer 20

Distinct differences in secondary sexual traits btwn females and males
Ex. colouration, vocalizations, body size, etc

Question 21

What is a hybrid zone?

Answer 21

Regions where members if diff species meet and mate, producing hybrids

Question 22

What is fusion?

Answer 22

Hybrids are as fit as parents, weakening reproductive barriers

Question 23

When can speciation begin?

Answer 23

When gene flow is interrupted btwn populations