Snapping shrimp used to be able to swim from the Atlantic Ocean to the Pacific Ocean by traveling between North and South America. However, when the Isthmus of Panama appeared (a land bridge that connects the Americas), the shrimp could no longer travel between the oceans and evolved into different species. This an example of:

a. sympatric speciation
b. allopatric speciation
c. punctuated speciation
d. genetic drift

B. Allopatric speciation

Explanation: Allopatric speciation is a term used in the field of Biology to describe the separation of a specie from its own members by Geographical barrier

Tthis will prevent the species from interacting with each other either Sexually or through other means, this barrier can be in the form of physical structures like mountains, rocks,buildings Icebergs etc. This type of speciation can lead to extinction of a specie as it can may be difficult for population growth or development of the affected species.

primary succession begins with a bare rock and ends with a forest secondary succession begins after a natural disaster where there is a temporary setback after a forest fire or local destruction, but the surrounding area can fill in

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."