360 Evolution? The Fossils Say YES!
case that humans had evolved and did so in Africa. Nevertheless, the hominin fossil record
(especially of our earlier ancestors, who all lived in Africa) was still quite poor for several
decades after 1924 because most anthropologists focused on very young European mate-
rial and could not accept Darwin’s insight that our closest ape relatives lived in Africa, and
therefore we probably originated there, too.
Contrary to what creationists say, the fossil record of humans is no longer as poor as
it was even 40 years ago. Decades of hard work in the field by hundreds of scientists has
turned up thousands of hominin fossils (fig. 15.2), including a few good skeletons and many
good skulls that show clearly how humans have evolved over 7 million years. This ava-
lanche of new discoveries every year has occurred despite the handicap that hominin fossils
are delicate and rare, and only one or two are found for every hundred fossil pig or fossil
horse specimen found in the same beds in eastern Africa. A tour through the bomb-proof
hominin vault in the Kenya National Museum in Nairobi is a revelation: a whole room full of
fossils that document our evolution, and whose existence the creationists must deny. Many
other museums in Africa, Europe, and Asia have similar large collections of our early ances-
tors, so there are lots of fossils to work with now (and even more ideas about how to inter-
pret them, which is a good thing in science). Fortunately, there are now books such as Eric
Delson’s (1985) Ancestors: The Hard Evidence, which was once part of a traveling museum
exhibit. These books and exhibits allowed the public to see these precious fossils up close for
the first time and realize that the creationist view of the human fossils record is a lie. Since
then, anthropologists have been much better at displaying and publicizing the quality of
the hominin record and demonstrating that they do not have any skeletons hiding in their
closets. Now there are a number of beautifully illustrated books with excellent full-color
photographs of the actual specimens published (listed at the end of the chapter), and there is
no longer any excuse for someone who wants to see what the fossils really look like.
The entire story of human evolution is too long and detailed to be discussed in a sin-
gle chapter, so we will just touch upon the highlights. The short version is this: dozens of
human species and genera are now known, forming a very bushy family tree that spans
almost 7 million years of human evolution, mostly in Africa (fig. 15.3). The exact details of
how all these fossils should be named or how they are interrelated is always controversial
because many of the specimens are incomplete, and anthropologists are famous for being
argumentative and contentious. But no matter how the arguments swing from year to year,
the amazing quality of the hominin fossil record is an objective fact, not someone’s inter-
pretation or guesswork.
First, let us place humans in a broader context. We are members of the order Primates,
the group that includes not only ourselves and the great apes but also the Old World mon-
keys (Cercopithecidae), New World monkeys (Cebidae), and lemurs, lorises, bush babies,
pottos, and many other archaic primates still alive today (fig. 15.4). We can trace the fossil
record of most of these lineages back to the Cretaceous and Paleocene primate Purgatorius,
whose name has interesting and ironic religious implications. (It was so named from Purga-
tory Hill in the Hell Creek Formation of Montana, where it was found). In the early Cenozoic,
the globe was much warmer and more densely vegetated, and there was a huge diversity
of different archaic primates distantly related to lemurs and other “prosimians,” including
the plesiadapids, adapids, omomyids, and many other groups (see Beard 2004, for an out-
standing account). If you collect fossils in Paleocene or early Eocene beds in places such as
the Bighorn Basin of Wyoming, primates are one of the most common fossils, and enormous