Fri,nov 18 , 10
Inportance of ring species
- adjacent species can interbreed
- different features of ring species.
- They can co-exist in the same area but they don’t interbreed( refer to image
on importance of ring species.)
- Species next to one another can interbreed but they can’t interbreed with
- They can reproduce hybrids but they don’t well because they are mediums(
no camflauge ( blend in or mimicking )
- Hydrids die sooner and can’t find mates.
- Can show us wat happened during speciation and how species have evolved.
Themes of speciation
1. Anagensis- hard to identify, happens over a long period time= evolve into
2. cladogensis – divergence of one species into 2 or more.(branching) – more
common form of speciation
modes of speciation
1. Allopatric = geographical speciation (natural selection, genetic drift and
mutation) are the microevolutionary mechanisms tht can lead to speciation.
(midterm question) === clicker question – refer to PP .
- matuation is acted on by NS and genetic D.
- 2 step process= pops become geographically separated
- evolutionary mechanisms tht work in both the pops..but will act differently
on both the gens
- vicariance: separation by geography( physical barrier)
- differences in ecolutionary differences mechanisms result in accumlation of
genetic differences tht reproductively isolate the pops.
- Gene flow is not a opera