Linnaeus was the Swedish botanist who created taxonomy, a system for naming and classifying organisms.

Leclerc was the French naturalist who argued that that the relationship between organisms and their environment was dynamic.

Erasmus Darwin was an English physician who conducted systematic observations of domestic and wild animals, fossils, and their anatomies. In his book Zoonomia, he proclaimed the common ancestry of all animal species.

Lamark proposed a theory of evolution that focused on acquired characteristics, or changes that occur during an organism's lifetime.
One critique of his theory was that it focused on changes at the individual level. We now know that populations evolve, not individuals.

James Hutton (1726 - 1797) was a Scottish geologist who is responsible for the theory of uniformitarianism. He argued that the earth went through cycles of disrepair and renewal. As rocks and soils were exposed to the elements, they eroded. New sediments were formed and later buried to be turned into rock by heat and pressure. This cycle continued uninterrupted. His contribution to evolution theory was an understanding of the Earth as changing and dynamic, which is necessary to understanding deep time.

Considered the father of geology, Lyell's work had a strong influence on Charles Darwin. He was a major proponent of the idea that the earth was shaped entirely by slow-moving forces still in operation today, acting over a very long period of time. He expanded upon the earlier work of Hutton.