Question

Describe the four basic causes of evolution: natural selection, mutation, genetic drift, and gene flow.   (please 400-500 response)

Answer 1

Four causes of evolution:

1.Mutation:random heritable change in gene or chromosome,resulting from additions,deletions,or substitutions of nitrogen bases in DNA sequences(they are source of genetic variation and serve as raw material for evolution to act)they occurs at different group like gene mutation,chromosome mutations,genome mutation.

2.Natural selection:favoring of individuals with characteristics that enhance survival and reproduction.they usually predominate in large populations.

3.genetic drift:genetic change due to chance.they predominates small ones.Effect of genetic drift is larger in small population and smaller in large populations.The process may cause gene variants to disappear completely,therby reducing genetic variability.

4.gene flow:also known as gene migration. refers to the transfer of genes from gene pool of one population to another.gene flow may change the frequency and/or the range of alleles in the populations due to migration of individuals or gametes that can reproduce in the different population.transfer of gene across population boundaries.Gene flw has effect of minimizing the genetic differences between populations.