Question

If in a given environment no sexual reproduction will take place, what will be the cause of variation of organisms

Answer 1

Normally, we'd rely on sexual reproduction to produce unique genetic combinations.

This is done so that the next generation of organisms can be better equipped to take on the challenges of the environments/situations that they face. However, in the absence of sexual reproduction, there has to be a mechanism in place that would lead to variation.

Why would mutation aid in providing variation?
Let's say that I have a population of bacteria that are susceptible to a certain antibiotic

Answer 2

Once I apply antibiotic to the colony of bacteria, most of the bacterial cells will die because they are similar genetically. The bacteria that survive, however, are the ones that have mutated randomly prior to antibiotic exposure and have only come to the forefront once their "competition" has died off

Answer 3

http://prntscr.com/4tjoe4

Answer 4

Mutations will provide genetic variation to a species in the absence of sexual reproduction and, in some cases (especially in the case of antibiotic resistance in bacteria) the mutation can prove to be beneficial to the organism.

Answer 5

As shown also on the board, these mutations, if beneficial, will be passed down through multiple generations -----> http://prntscr.com/4tjpb9

Answer 6

And the thing about mutations is that they're caused by DNA polymerase reading errors that aren't fixed in time... DNA polymerase makes about 1 error for every 1,000,000 or so base pairs it synthesizes!!! It usually goes back and fixes these errors to improve the rate of error to 1 error in a billion base pairs synthesized

But there's always a chance that an error can occur and that DNA polymerase won't be able to fix it...Once the error occurs and the next replication event has taken place, the error is then considered a mutation