GENETICS × HUMAN EVOLUTION

Reading the Dead

1984 to 2010 CE

Phanerozoic · Cenozoic · Quaternary · Holocene · Meghalayan

DNA survives in bones and skins for tens of thousands of years, but it comes out broken into short pieces and chemically scarred in a particular way at the ends. For a while that damage made the field unreliable, since a stray modern strand looks better than a genuine ancient one. Then the damage itself became the test: a sequence that shows none of it has no claim to be ancient. A draft Neanderthal genome followed in 2010.

Why it matters

Extinct species stopped being silent. Much of what is known here about Neanderthals and Denisovans, and about the Black Death and the first dogs, was read out of their own DNA rather than inferred from their bones.

Dating & uncertainty

The range runs from the first sequences of an extinct animal, obtained in 1984 from dried muscle on a museum specimen, to the draft Neanderthal genome of 2010. It is a span rather than a date because the early work was not yet trustworthy: what changed in between was not the age of the samples but the ability to tell a genuine ancient sequence from a modern one.

Sources

1. Higuchi et al. (1984), Nature · DNA sequences from the quagga, an extinct member of the horse family
2. Green et al. (2010), Science · A draft sequence of the Neandertal genome
3. Dabney, Meyer & Pääbo (2013), Cold Spring Harbor Perspectives in Biology · Ancient DNA damage

Earth history as one day

23:59:59.9992799 µs before midnight

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