Final answer:
Charles Darwin is credited as the father of modern evolutionary theory. He developed his key ideas about natural selection during his observations on the Galápagos Islands.
Step-by-step explanation:
The famous scientist considered the father of modern evolutionary theory is Charles Darwin. Darwin developed the theory of evolution by natural selection, which revolutionized the field of biology. His pivotal observations were made on the Galápagos Islands during his voyage on the HMS Beagle from 1831 to 1836. On these islands, Darwin noted the distinctive adaptations of species, such as the beak variations in finches, which led him to propose that species evolved over time from common ancestors through a process of natural selection.