22-Speciation

Question 1

Groups of organisms that share a suite of genetic and morphological attributes, and are reproductively isolated from other such groups

Answer 1

Species

Question 2

Divergence of biological lineages and the emergence of reproductive isolation between lineages

Answer 2

Speciation

Question 3

Biological species concept (BSC)

Answer 3

• reproductive isolation is key
• no gene flow between groups of organisms
• prezygotic and postzygotic barriers

Question 4

Prezygotic barriers

Answer 4

Prevent fertilization between 2 species

Question 5

Postzygotic barriers

Answer 5

Prevent hybrid zygotes from developing/reproducing

Question 6

Live in different habitats

Answer 6

Habitat isolation

Question 7

Breed at different times (day, year, or life)

Answer 7

Temporal isolation

Question 8

Rituals that attract one mate to another disrupting gene flow

Answer 8

behavioral isolation

Question 9

Reproductive “pieces” dont fit

Answer 9

Mechanical isolation

Question 10

Sperm and egg are not compatible

Answer 10

Gametic Isolation

Question 11

Hybrid development is incomplete and individual is frail

Answer 11

Reduced hybrid viability

Question 12

Because of chromosomal differences, hybrid cannot breed

Answer 12

Reduced hybrid fertility

Question 13

Hybrid is fertile, but cannot compete with full species

Answer 13

Hybrid breakdown

Question 14

Morphological species concept

Answer 14

• species can be identified by body shape and other structural features
• (fossils, asexual organisms)

Question 15

Lineage species concept

Answer 15

A species is one branch on the tree of life, each has a history that begins with a speciation event and ends either at extinction, or another speciation event

Question 16

New species arise from 2 processes, depending on how gene flow is interrupted. (What are they?)

Answer 16

• allopatric speciation

- sympatric speciation

Question 17

• physical barrier separates a population
• mutations arise in sub populations
• Natural selection, genetic drift, and/or sexual selection cause genetic differences
• Results in reproductive isolation creating 2 sister species
• (Founder events)

Answer 17

Allopatric speciation

Question 18

• speciation events occurring when populations are in contact with each other
• polyploidy
• habitat differentiation
• sexual selection

Answer 18

Sympathy speciation

Question 19

Polyploidy

Answer 19

• accident during meiosis, results in extra set of chromosomes
• more common in plants
• makes gametes that are incompatible with original species

Question 20

Habitat differentiation

Answer 20

• genetic factors arise that allow some members of a population to exploit a resource which other cannot
• (disruptive selection)

Question 21

Sexual selection

Answer 21

• mate force is driving factor in speciation

- mate choice is so drastic it leads to reproductive isolation

Question 22

Ecological and behavioral factors influence speciation rates

Answer 22

• populations of species with a specialized diet may be more likely to diverge than those with generalized diets
• speciation rates are faster when animal pollinated, than when wind pollinated
• mechanisms of sexual selection result in high rates of speciation
• speciation rates are usually higher in groups with poor dispersal rates

Question 23

The rapid proliferation of a large number of descendant species from a single ancestor species

Answer 23

Evolutionary radiation

Question 24

When a rapid proliferation of species results in an array of species that live in a variety of environments

Answer 24

Adaptive radiation