Lecture 21: Species, Speciation & Hybridization

Question 1

What is microevolution?

Answer 1

Changes within a species/small group of organisms

Question 2

What are some sources of microevolution?

Answer 2

Natural selection, genetic drift, mutation and migration

Question 3

What is a species?

Answer 3

Traditionally defined by phenotypic similarity

Question 4

What does sympatric mean

Answer 4

Within a region

Question 5

What does allopatric mean

Answer 5

Across regions

Question 6

What does taxonomic or morphological organisms mean?

Answer 6

On distinct measurable differences

Question 7

What does biological organisms mean?

Answer 7

Based on inter-fertility among individuals

Question 8

What is the Biological Species Concept?

Answer 8

1) Geographical isolation alone is not enough
2) Possible interbreeding in the wild

Question 9

Why is the weakness of Biological Species Concept?

Answer 9

Does not apply well for bacteria, asexuals, highly self-fertilizing species or fossils

Question 10

Where does speciation more commonly occur?

Answer 10

Allopatric speciation (species that are isolated) due to minimal gene flow

Question 11

What are the stages of reproduction isolation (RI)

Answer 11

1) Finding a compatible mate
2) Fertilization
3) Development and growth of zygote
4) Adult survival and reproduction
5) Growth, survival and reproduction of offspring

Question 12

What stages of reproduction isolation are pre-zygotic isolation?

Answer 12

1) Finding compatible mat
2) Fertilization
3) Development and growth of zygote

Question 13

What stage of reproduction isolation are post-zygotic isolation?

Answer 13

4) Adult survival and reproduction
5) Growth, survival, reproduction of offspring

Question 14

What are pre-zygotic barriers?

Answer 14

Prevent mating or fertilization so no zygote gets formed

Question 15

What are some examples of pre-zygotic barriers?

Answer 15

1) Geographical
2) Ecological
3) Temporal
4) Behavioural
5) Sexual mechanism (different genital structure compatibility)
4) Cellular (sperm-egg compatibility)

Question 16

What factors pre-zygotic isolate in Apple Maggot flies and Hawthorn Flies?

Answer 16

Habitat and temporal isolation
- Different timing of fly mating on a preferred host plant

Question 17

What factors pre-zygotic isolate Abalone?

Answer 17

Cellular
- Requires certain sperm lysin protein to fertilize egg

Question 18

What are post-zygotic barriers?

Answer 18

Prevent proper functioning of zygotes once they are formed

Question 19

What are the two types of post-zygotic barriers?

Answer 19

1) Intrinsic
2) Extrinsic

Question 20

What is intrinsic post-zygotic barrier?

Answer 20

Not being capable of surviving, producing children or abnormal development of hybrids

Question 21

What is extrinsic post-zygotic barrier?

Answer 21

Ecological mismatch of hybrid phenotype to environment

Question 22

What is an example of intrinsic post-zygotic?

Answer 22

Mules, a sterile hybrid between male donkey and female horse

Question 23

What is an example of extrinsic post-zygotic?

Answer 23

A species of butterfly that are bright in colour. This results in high predator and lower mating success

Question 24

What is adaptive radiation?

Answer 24

The evolution of ecological and phenotypic diversity within a rapidly multiplying linage as a result of speciation

Question 25

What are four common features to identify an adaptive radiation?

Answer 25

1) Recent common ancestry from a single species
2) Phenotype-environment correlation
3) Trait utility
4) Rapid speciation

Question 26

What is an example of adaptive radiation?

Answer 26

Darwin’s finches

Question 27

What causes Adaptive Radiation?

Answer 27

1) Ecological Opportunity
2) Origin of key innovation
3)High rates of speciation characterize the clade

Question 28

What is polyploidy

Answer 28

Organism, tissue or cell with more than two complete sets of homologous chromosomes

Question 29

What is an example of allopolyploidy?

Answer 29

Duplicated chromosomes of hybridization between species

Question 30

What is an example of autopolyploidy?

Answer 30

Duplicated chromosomes within a species