Lecture test 1: sympatric and allopatric speciation

Question 1

What does allo mean

Answer 1

different, other

Question 2

What does sym mean

Answer 2

same

Question 3

Example of allopatric speciation

Answer 3

Flightless bird on the galapagos probably came from flying species on the mainland

Question 4

Alloptaric speciation

Answer 4

Gene flow is interrupted or reduced when a population is divided into geographically isolated subpopulations. Result in reproductive barriers

Question 5

Separate populations may evolve independently through:

Answer 5

mutation, natural selection, genetic drift

Question 6

What may arise as a product of genetic divergence and give example

Answer 6

Reproductive isolation (barriers). Mosquito fish have adapted to their new environments, different predators (new body shapes for fast swimming, swimming for long periods of time etc). They were once the same species and now do not mate because of sexual preferences to body shapes

Flies separated and raised in either maltose or starch. After 40 generations, they only wanted to mate with flies from the same medium.

Question 7

When does sympatric speciation occur

Answer 7

New species originates despite not having any geographic isolation from the parent species. Occurs if gene flow is reduced by factors including polypolidy, sexual selection, and habitat differentiation

Question 8

Polypolidy (what is it and types)

Answer 8

• Extra sets of chromosomes due to accidents in cell division
• Common speciation event in plants (80% of plants alive today are result of polyploid event)
• **An allopolyploid is a species with multiple sets of chromosomes derived from different species (drives speciation)
• An autopolyploid has more than 2 chromosome sets that came from the same species

Question 9

Polyploid example

Answer 9

At least 5 new plant species have originated by polyploid speciation since 1850 (oats, cotton, wheat)

Question 10

Sexual selection definition and example

Answer 10

Evolution of a new species based on certain criteria that mates find in their partners. Sexual selection for mates of different colors has contributes to speciation in cichlid fish in Lake Victoria

Question 11

Habitat differentiation example

Answer 11

Isolation based off of food availability.
- North American maggot fly can live on hawthorn trees as well as more recently introduced apple trees (natural selection for flies that develop faster so they can get the fruit. Flies develop faster because apples mature faster than hawthorn fruits)

Question 12

In allopatric, Even if contact is restored between species, ________________

Answer 12

interbreeding is prevented