Natural selection<span> acts upon two major sources of genetic variation: </span>mutations<span> and</span>recombination<span> of </span>genes<span> through sexual </span>reproduction<span>. Most </span>mutations<span> do not affect the reproductive fitness of individuals -- some may be beneficial, some may be harmful, and </span>many<span> may be neutral. </span>Mutation rates<span> per gene are generally low</span>
The answer is C I just learned this the other day trust me
Answer:
index fossils are those fossils which have wide geographical distribution and short life span. so if they are found in a particular age, it means they belong in that age and they cannot be found in formations younger then that. for example if there is an index fossil of Permian age, we can corellate the permian age formations
index fossils have a very short life span which means they only can be found in a particular age.
