WATCH:
Is The Human Race In Danger Of Becoming Extinct Soon?
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Louise
Leakey
5
July, 2013
In
the rush of today's world, and with more than half of us now living
in cities, the majority of people are less and less connected with
the spectacle of Nature. How many of us stop to think about our place
on the planet, and how close we came as a species to going extinct
just 75,000 years ago? How many of us appreciate that all our roots
are African, as Homo sapiens left the continent only some 75,000
years ago to populate the globe?
The
fossil record presents an opportunity to contemplate how this human
story unfolded, although we will never find the fossils that
represent the complete record, as preservational events are in
themselves very rare. With the discovery of Zinjanthropus at Olduvai
Gorge in 1959, my grandmother Mary Leakey pioneered the research in
East Africa, with my grandfather Louis. Many more spectacular fossil
finds have since been made both in Africa and elsewhere, by many
researchers driven to understand our past. These are exciting times,
and new and often unexpected finds are announced quite regularly.
Since I presented this TEDTalk in 2008, we now know of several new
species of hominins from different places in Africa, including
additional fossil material from Lake Turkana, helping us to
understand our own genus Homo.
Technology
has furnished us with a fascinating genetic story as well, allowing
us to map the migration of early humans in more intricate detail than
ever before. The work of Spencer Wells, a National Geographic
Explorer in Residence, allows us to participate in his study by
providing a cheek swab to discover how we fit in to this incredible
journey of humanity. In addition, genetic research has confirmed that
there was gene flow between Homo sapiens and Neanderthals. Perhaps
even more surprising was the further discovery that we humans also
shared genes with a totally different hominid species, only known
from DNA extracted from a finger bone found in a cave in Denisova in
southern Siberia.
To
put the history of life on planet earth into a time perspective,
imagine unrolling a toilet roll down a hillside. If there are 400
sheets of tissue paper in the roll, then the very first life in the
oceans is seen at sheet 240. The age of the dinosaurs begins at sheet
19. Dinosaurs in their many forms and great diversity are around for
14 and a half sheets. Dinosaurs are extinct by the end of the
Cretaceous, 5 squares from the end, making way for the mammals. Our
story and place on the timeline as upright walking apes begins only
in the last half of the very last sheet. The human story as Homo
sapiens, is represented by less than 2 millimeters of this, some
200,000 years.
Our
own individual lifetimes cannot be depicted on this final sheet of
the toilet roll as it would be too thin a line, yet we have been
witness to more change to the planet, to the diversity of life,
global climate and natural habitats in this same time period. We are
undoubtedly the cause of the sixth mass extinction event that the
planet has seen in its history.
The
last 50 years has shown an enormous increase in human population, but
also extraordinary leaps in technological innovation. The question
that needs to be asked is if we can rise to the opportunity, to use
our technology to better understand our impact, to stem the tide of
extinction on land and in the oceans, to preserve what we have left,
and to discover and understand more about our past. What the fossil
record does do is to force us to contemplate our place on the planet.
We are but one species of several hominids that inhabited planet
earth and like our distant cousins who went extinct fairly recently,
our time on planet earth is also finite. It won't take much to tip
the balance against us.
Follow
me on Twitter @louiseleakey, and at africanfossils.org
For
a digital and interactive look at some of the showcase finds from
Africa you can see www.africanfossils.org and follow on Twitter for
updates to this digital collection. In a few months downloadable
files will be available here for 3Dprinting
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