Natural selection can only occur because of a variety in a population. Natural selection refers to environmental factors that affect a population and causes some of the population to have more surviving offspring than others. An example is a giraffe with a longer neck will be more likely to survive and reproduce (as it can gather more food from taller trees)
To calculate the population density, you will divide the population by the size of the area. Hope I helped!
Yes it is it usually
entirely
That easy..............<span>21 one is your technical answer according to todays rules but scientist used to think it was only 20 so 20 would be your answer</span>
