Evolution

Evolution is define as a gradual process which something changes into a different more complex or better form.

This is done by a process call NATURAL SELECTION
This is where favorable heritable traits become more common in successive generations of a population of reproducing organisms, and unfavorable heritable traits become less common.
A phenotype describes any observed quality of an organism, such as its morphology, development, or behavior, as opposed to its genotype - the inherited instructions it carries, which may or may not be expressed.

Charles Robert Darwin (12 February 1809 – 19 April 1882) was an English naturalist. After becoming eminent among scientists for his field work and inquiries into geology, he proposed and provided scientific evidence that all species of life have evolved over time from one or a few common ancestors through the process of natural selection.
His five-year voyage on the Beagle established him as a geologist whose observations and theories supported.His journal of the voyage made him famous as a popular author.
The Beagle survey took five years, two-thirds of which Darwin spent on land. He carefully noted a rich variety of geological features, fossils and living organisms
and methodically collected an enormous number of specimens, many of them new to science.[1] At intervals during the voyage he sent specimens to Cambridge together with letters about his findings, and these established his reputation as a naturalist
When the Beagle returned on 2 October 1836, Darwin was a celebrity in scientific circles.