Molecular Biology

[jimslady]

In a population of ear infection causing bacteria, there may be some members with a rare antibiotic-resistant allele. The environment changes when the person with the ear infection takes an antibiotic. All the bacteria with a sensitive allele die, but the resistant bacteria survive and thrive.
A. Has the frequency of each allele in the population changes?
B. Is this an example of natural selection? Why?
C. Is this an example of microevolution? Why?

Thanks for any help with this one.

[biostudent84]

A. Yes. The antibiotic-resistant bacteria live, while the rest die...this makes the population near-100% have antibiotic resitant genes.

B. Yes. The "strongest" survived...in this case, the organisms that were antibiotic resistant.

C. Debatable, but I say yes. In this particular population, the majority of the species went from being non-antibiotic resistant to antibiotic resistant.

Kyle

[RobJim]

Are you getting questions on microevolution in your class? I didn't think it was a scientific term.

EDIT - It looks like it is actually used by scientists.

http://evolution.berkeley.edu/evosite/evo101/IVMicroevolution.shtml