EVOLUTION × TECHNOLOGY

Darwin: Descent with Modification

1859 CE

Phanerozoic · Cenozoic · Quaternary · Holocene · Meghalayan

Descent with modification, the theory that Darwin published in 1859, gives every living thing a common ancestry and explains without a designer how organisms fit their environment.

Descent with modification is Darwin's theory that every living thing descends, with changes, from a common ancestry. It accounts for the fit between an organism and its environment without a designer. Its mechanism, natural selection, follows from three observations: offspring differ from their parents, more are born than can survive, and the differences affect which ones survive. The differences that survive more often become more common. Alfred Russel Wallace arrived at the same theory independently, and his version and Darwin's were presented jointly in 1858. Darwin published the theory in 1859 in On the Origin of Species.

Why it matters

The rest of this timeline is read through Darwin's theory. Before it, fossils and strata, the layers of rock that contain them, formed a succession whose order had no explanation. The theory explains that order by descent, and turns the succession into a family tree. Every date on this timeline is a point on a branch of that tree.

Earth history as one day

23:59:59.99683.2 ms before midnight

if Earth’s 4.54 billion years were compressed into a single day