Lecture 20 Flashcards
What is speciation
The process in which one species divides into two
How do you initiate the speciation process
Need to intially restrict gene flow between isolatd populations
Whats allopatric speciation
Speciation that involves physical seperation between the two populations
Whats vicariance
Large population split into two e.g. by moutain uplift
Whats peripatric/ dispersal
A smaller population is established outside the orignal population e.g. oceanic islands
Whats sympatric speciation
A population can be split into two via two or more reproductively isolated populations while in the same place
Whats parapatric speciation
When neighbouring populations of species are geographically connected and exchange genes but still diverge
Example of vicariance
Isthmus of Panama in central America
Patterns of speciation in birds such as the south American Andes
Example of peripatric
Archipelago and island bird colonisations
Examples of sympatric speciation
Rhagoletis apple maggot fly and hawthorn trees
Example of paraptric speciation
Lizards at white sands
Whats ecological speciation
Evolution of reproductive isolation between populations as a result of ecologically based divergent natural selection
Example of ecological speciation
Monkey flowers
Example of experimental evolution in the lab
Drosophila reared with different foods such as maltose, starch. Found they became reproduvtively isolated
What is sexual selection defined as
Differential reproduction as a result of variation in the ability to obtain mates
