Answer:
The correct answer is b. must be present in a population before natural selection can act upon the population
Explanation:
Genetic variation can be caused by mutation, recombination between chromosomes during meiosis and by fusion of two genetically different gametes during sexual reproduction.
This genetic variation is necessary for the evolution of any population. Natural selection acts on every individual and it decreases the frequency of those alleles that are not suited for the environment and increase the frequency of those alleles which helps the individual to survive in the changing environment.
Therefore genetic variation must be present in the population before natural selection act on the.
The initial source of energy is sunlight
Waterrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
Answer:
help interpret earth's past
great environmental indicators
created from living things that are buried
help us understand day to day life forms and ancestors
Explanation:
Answer:
o think this question is asked two times right