help with biology?

Question

Consider a hypothetical situation in which spatial (geographic) isolation leads to the formation of a new species. In 5 separate sections, use the following terms to describe the scenario from beginning to end.

1. Spatial isolation
2. Founder effect, bottleneck
3. Gene flow
4. Natural selection
5. Reproductive isolation, biological species

does anyone know? i have no clue. =[

Answer 1

1. Spatial isolation means that a population is separated from the rest of the members of that species by some sort of physical barrier: on an island, on the other side of a mountain range, ...
2. A bottleneck occurs when the separated population doesn't have very many members -- the gene pool doesn't have much variation, so the resulting generations don't have a lot of genes to choose from.
3. Gene flow is what happens when individuals move into or out of a population. This has more effect when the population in question isn't very big. If individuals with different genes move into the population and then they reproduce, their different genes become part of the gene pool. If individuals move out of a population, they take their genes out of the gene pool.
4. Natural selection determines which individuals live and reproduce according to which ones have variations that help them survive. When a population is isolated, natural selection helps fit the population to its environment.
5. Reproductive isolation just means that some members of a population don't interbreed with the others, even though they still live in the same area. An example: certain individual frogs only mate in a later season than the rest of the population. Those frogs won't share any genetic changes with the rest of the frogs any more, so they can gradually become different. The same thing would happen if certain birds sang a slightly different song that kept them from interbreeding with the rest of the population.

Answer 2

Spatial isolation: because the area is isolated the speices doesn't need to deal with mirgrant and outside speices so there is less competition. They will evolve to be niche speices specializing. Example: Galapogos islands

Founder Effect: Since there is no outside gentic material moving in the traits of the orignal inviduals will be passed on to their offspring this may include their flaws and cause problems if the speices in breed. Example: American Amish

Gene Flow: The speices will continue to adapt in get better as time goes on until it reaches a pinnical point

Natural Selection: The environment will dictate the gentic survival of the species. With no outside gentic material the species will have to rely on what is already in their DNA

Reproduction Isolation: The species will evolve until they are no longer complatialbe with the other species like them in the outside world to the point they cannont be cross bred making the species on able to have children amoung themselves.