Page 83 - The Restless Earth Fossils

2 Fossils

both imply that the continent of Africa served as home to many
of the species that would contribute to the human story.
Our species name, Homo sapiens, literally means “man, the
wise.” We admire ourselves for being new and quite unique, but
we really are an evolutionary patchwork. “The human we see in
today’s mirror,” says Christopher Sloan, author of Smithsonian

Watch Where You Step

In 1976, on an African field trip at a site called Laetoli, two young
scientists got bored and starting throwing elephant dung chips
at each other. (In his book Lucy: The Beginnings of Humankind,
paleontologist Donald Johanson explained that sometimes there
is not much to do on remote digs.) One fellow, Andrew Hill, while
ducking an elephant dung pie and looking for another, discovered
what appeared to be animal tracks in a volcanic ash layer in the
dry streambed on which he was standing. The pie fight stopped and
the tracks were confirmed, but the site could not be excavated until
the following year.
In 1977, Mary Leakey and members of her scientific team dis-
covered elephant and other animal tracks at the same site. Among
those tracks were a pair that looked like they might have been
made by a hominin, but it would take some effort to completely
expose the delicate layer of ash in which they were impressed. At
first Leakey gave fossil bone hunting priority over the track exca-
vation, but as paleontologist Tim White exposed more and more
tracks, excitement grew among the rest of the crew. Ultimately,
over several field seasons, 70 recognizable footprints emerged in a
path nearly 80 feet (24 meters) long. “Make no mistake about it,”
said White. “They are like modern human footprints. If one were
left in the sand of a California beach today, and a four-year-old
were asked what it was, he would instantly say that somebody had
walked there.”

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