Karl Ernst von Baer

First rigorous generalization in comparative developmental biology

Karl Ernst von Baer

First rigorous generalization in comparative developmental biology Showed that adults of more recently evolved

species often differ markedly from adults of more primitive species

Argued that embryos of more recently evolved species often closely resemble the embryos of more primitive species

Charles Darwin - born in 1809

Charles Darwin 1831-1836

Circumnavi-gated the globe aboard the H.M.S. Beagle

Charles Lyell

Highly influential geologist

Introduced the notion of uniformitarianism

Gave Darwin the gift of time

Thomas Malthus

In 1798, he wrote An Essay on the Principle of Population

Charles Darwin 1838

Darwin’s notebooks mention natural selection

Charles Darwin 1844

Darwin drafts a manuscript laying out his ideas at length.

The manuscript remains unpublished until . . .

Alfred Russel Wallace 1858

Wallace sends Darwin a letter from Malaysia with idea of natural selection described

Charles Darwin 1859

Publishes The Origin of the Species that claims that natural selection causes adaptive evolutionary change

Gregor Mendel 1866

Uses pea genetics to show that genes behave like particles present as two copies Darwin either failed to

read Mendel’s paper or did not realize the significance of the paper

Ernst Haeckel

Publishes on general morphology of organisms and states his biogenetic law: ontogeny recapitulates phylogeny

Correns, Tschermak and de Vries 1900

Rediscover Mendel’s laws