Evolution, 4th Edition

554 CHAPTER 21

Starting about 600 Kya, a second wave of hominins spread out of Africa and

across Europe and Asia (FIGURE 21.9B). By about 500 Kya, that species (H. heidel-

bergensis) gave rise to the Neanderthals, named after the Neander Valley^3 of west-

ern Germany, where their fossils were first discovered. Neanderthals had dense

bones, a thick skull, and a projecting brow (FIGURE 21.10). Their brains were larger

than ours (up to 1500 cc), and they had an elaborate culture that included stone

tools, art, and burial of the dead [65].

In 2010, a research group led by Svante Pääbo published a remarkable paper.

They sequenced a Neanderthal genome using DNA extracted from fossils. They

confirmed that humans and Neanderthals are very closely related but genetically

distinct [22]. Pääbo’s group then sequenced DNA from a 50,000-year-old finger

bone found in a cave in Siberia. Astonishingly, its genome is sufficiently distinct

that it must have belonged to another group of hominins that diverged from

Neanderthals perhaps 400 Ky earlier [64]. Named for the cave where the fossil was

found, this group is called Denisovan. The phylogeny of the hominins, on which

humans are a leaf, more closely resembles a densely tangled bush than an erect

sequoia.

(^3) The German word Thal (“valley”) is pronounced “tal.” Today it is spelled Tal, and the name of
the hominin is sometimes spelled “Neandertal” in English.
Futuyma Kirkpatrick Evolution, 4e
Sinauer Associates
Troutt Visual Services
Evolution4e_21.09.ai Date 02-02-2017
Africa
(A) (B)
1900 Kya1900 Kya
Africa
600 Kya600 Kya
Neanderthals
Denisovans
Homo
erectus
Cranial
capacity
increases
Face becomes
more vertical and
jaw less projected
FIGURE 21.9 Before humans did so, other hominins spread out of Africa at least twice.
(A) Starting about 1900 Kya, H. erectus spread to the Middle East, Europe, and Asia. It
became extinct without contributing to human ancestry outside Africa. (B) The ancestor
of Neanderthals (H. heidelbergensis) left Africa about 600 Kya. It spread into Europe
and Asia, where it gave rise to the mysterious Denisovans. Later, both Neanderthals
and Denisovans hybridized with humans outside Africa.
Futuyma Kirkpatrick Evolution, 4e
Sinauer Associates
Troutt Visual Services
Evolution4e_2110.ai Date 11-02-2016
Human Neanderthal
FIGURE 21.10 Skulls of a human from 28 Kya
and a Neanderthal from 60 Kya. Neanderthals
had an even bigger brain than living humans,
but other features of their skull, such as the brow
ridge, were more like those of other apes.
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