How do beaver dams contribute to species diversity in the ecosystem?
a) provide access to food in winter
b) keep predators away from the ecosystem
c) provide a habitat for a variety of species
d) ensure that only beavers have access to water

The answer is:

C) provide a habitat for a variety of species.

Believe it or not, beaver dams actually help create a habitat for other species to live in. When a beaver creates a dam is creates a new pond where species can live in. In many cases beaver dams have also helped restore lost wetlands!

Hope this helps :)

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: