Which is the primary process by which evolution of life on earth occurs? natural selectionacquired characteristics vestigial retention speciation

natural selection

Explanation:

There are many processes through which evolution can occur like migration, mutation, genetic drift and natural selection. However, one of the most important triggering factor for evolution is natural selection .

What is natural selection:

In very simple words it can be considered as the process through which organisms that are better able to adapt to their surrounding environmental conditions survive and thrive, thereby they reproduce and transfer their characteristics in offspring, but those that have less ability to adapt to environmental conditions, tend to become less in number and ultimately eliminate.

How natural selection leads to evolution:

Now to understand how natural selection leads to evolution, we will take example of a population of beetles, some are brown and some are green in color. Now environment has limited capacity and it cannot support the survival of each and every population.

Here what happens is the green beetles are vulnerable to attack by birds because their color is visible to birds but brown beetles are less visible. What will happen that green beetles will be all eaten by birds and brown will keep surviving.

Now years later, beetles will have only brown color because evolution occurred and only fittest ones survive.

This is how natural selection leads to evolution.

Hope it helps!

where is the diagram?

if you insert the diagram ill be able to you

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."