Archaeologists found that there were fossil remains of extinct animals as they dug deeper into the strata. They could see similarities in the different fossils but could not comprehend why or how they existed. Darwin influenced the theory of evolution in his study of finches and tortoises of the Galapagos Islands. Though different, Darwin could note similarities that converged the different birds to the same ancestors. The tortoise in the different islands though seemingly similar, Darwin noted that they had distinct variation. His breakthrough was in 1859 when he published the book On the Origin of Species (Evolution and Natural Selection, 2010).
First, Darwin views a species as organisms that can vary over time and space. He says that the equivalent of today’s organisms that existed earlier in life varied in form and behavior from those of today, as do those in distanced geographic regions today. Fossils also differ thus supporting the claim (Evolution and Natural Selection, 2010).
Second, he says that all organisms have shared common ancestors. The relations can be traced over millions of years ago. Different organisms diverged from their common ancestry to form their own independent species. Sharing of common ancestry is manifested by the similarities that different species share today e.g. we share common ancestry with chimpanzees dating back around eight million years back. Lastly, Darwin puts forth that evolution is steady slow process. Fossil records showed this form of process plus the emergence of unprecedented novel organisms in Darwin’s time (Evolution and Natural Selection, 2010).
Natural selection entails variation, inheritance, excessive speed of population growth and differential survival and reproduction. Related organisms vary in form and behavior and include variations in body size, facial markings, hair color and so on.