- Category: Science & Technology
- Created on Sunday, 10 January 2010 09:00
- Written by Mike Ely
By Mike Ely
"New analyses reveal the mini human species to be even stranger than previously thought and hint that major tenets of human evolution need revision."
Scientific American November 2009
The hard evidence of human evolution has gathered over a century -- hundreds of skeletons, rooms full of early tools, a dozen or more hominid species, and detailed dating data that fixes our ancestors and cousins in time. It is a rich fossil record now augmented with increasingly sophisticated DNA evidence.
One important function of theory is to provide a bridge over the inevitable gaps in data (to connect the dots in ways that suggest a picture of causalities and interrelationships).
In other words, the overall picture we develop from existing evidence leads us to deduce where the missing evidence should be. The dots become narratives.And so, we had an emerging story of humanity -- evolving from apelike creatures in Africa, spreading out from the motherland as sophisticated big-brained, tool-making, wide-striding Homo erectus, and then again -- until Homo erectus, Neanderthal and Homo sapian species met at different points across Eurasia, and our own species emerged alone and triumphant 50,000 years ago.
It says something about the development of science, that the discovery of a new cave-full of fossils, one new "dot" in that record, can so upset that existing narrative.
If these small-brained, short "hobbit" humanoids had been found in Africa, if they had been found in soil that was 1.5 million years old, if they had been found surrounded by primitive chips of stone -- their bones would not have been AS remarkable. On close examination (of feet, wrist bones and brain cavity) they now clearly seem to be a distinctive species, yet not that different from the Australopithesines (made famous by Lucy).
But in fact, their bones were not found in Africa -- these bones were found in Indonesia (at the other extreme of the Eurasian land mass). They were found in soil that was 17,000 years old. And they were accompanied by relatively sophisticated stone tools.
This means (presumably) that the first hominids to leave Africa were creatures closer to Lucy than to Homo erectus -- without arches in their feet, and with small brains (about a third of modern humans). And it means that our species was not alone -- it had other hominids sharing the planet right into (relatively) modern times alongside us.
While our own species was starting to developing villages and agriculture in Turkey, domesticating dogs and developing bee-keeping , i.e. about 10-15,000 years ago, there may then well have been short human-like creatures living in Southeast Asia, hunting, thriving and perhaps even swapping culture with modern humans there.
One new dot of evidence -- one odd and unexpected cache of bones in a cave -- and new theoretical narratives have to emerge to encompass the new data. And this happens, naturally, amid great controversy -- as that new data is challenged: It is so unexpected that it is also suspect. Is the "hobbit" skull an aberration -- just one diseased individual? As the bones are closely studied, that seems less and less likely. The hobbits (it is now reported in a wonderful article from Scientific American) are not part of the Homo erectus family, they are more "primitive" in stark and distinctive ways.
Dogmatists -- including religious fundamentalists who oppose evolution -- seize on such eruptions within science. They use this to claim that such adjustments or discrepancies proof the unreliability of scientific theory (as if Genesis mythology is somehow validated each time human evolutionary narratives get refined!) But really, this is a glimpse of how human knowledge goes from less accurate to more accurate -- in jarring leaps, in painful adjustments, in shocking returns "to the drawing board."
As natural science grows and refines in front of us -- I take this as a lesson in how our social thinking too needs to be fluid and creative, craving the anomalous unexpected new data, tirelessly self-critical, eagerly changing and growing amid skeptical debate. Even our most well-worn narratives and well-tested assumptions can be (quickly, suddenly) upset by a new "dot" -- by a set of new dots, by a growing body of evidence gathered first in a fenced off void of suspicious anomalies. And, in fact, there is a growing mountain of new phenomena and experiences that are demanding a creative revolution within radical thinking.
I am always excited at every new development in the study of human evolution. It has been unfolding and deepening around us in ways crackling with diligence, creativity and the completely unexpected. And for those of us who are revolutionaries and communists, it is a living lesson -- of how real science and theory develop, and how nimbly we need to adjust our old theory. A narrative that defies new data is just a myth and a self-deception. A theory that has become entrenched orthodoxy is becoming brittle. And, to solve humanity's problems we all need to see things more and more clearly -- not clouded by our favorite myths and orthodoxies.
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From Scientific American November 2009 (note: the full article is available on their site, this is a synopsis)
Rethinking "Hobbits": What They Mean for Human Evolution
New analyses reveal the mini human species to be even stranger than previously thought and hint that major tenets of human evolution need revision
By Kate Wong
- In 2004 researchers working on the island of Flores in Indonesia found bones of a miniature human species—formally named Homo floresiensis and nicknamed the hobbit—that lived as recently as 17,000 years ago.
- Scientists initially postulated that H. floresiensis descended from H. erectus, a human ancestor with body proportions similar to our own.
- New investigations show that the hobbits were more primitive than researchers thought, however—a finding that could overturn key assumptions about human evolution.
In 2004 a team of Australian and Indonesian scientists who had been excavating a cave called Liang Bua on the Indonesian island of Flores announced that they had unearthed something extraordinary: a partial skeleton of an adult human female who would have stood just over a meter tall and who had a brain a third as large as our own. The specimen, known to scientists as LB1, quickly received a fanciful nickname—the hobbit, after writer J.R.R. Tolkien’s fictional creatures. The team proposed that LB1 and the other fragmentary remains they recovered represent a previously unknown human species, Homo floresiensis. Their best guess was that H. floresiensis was a descendant of H. erectus—the first species known to have colonized outside of Africa. The creature evolved its small size, they surmised, as a response to the limited resources available on its island home—a phenomenon that had previously been documented in other mammals, but never humans.
The finding jolted the paleoanthropological community. Not only was H. floresiensis being held up as the first example of a human following the so-called island rule, but it also seemed to reverse a trend toward ever larger brain size over the course of human evolution. Furthermore, the same deposits in which the small-bodied, small-brained individuals were found also yielded stone tools for hunting and butchering animals, as well as remainders of fires for cooking them—rather advanced behaviors for a creature with a brain the size of a chimpanzee’s. And astonishingly, LB1 lived just 18,000 years ago—thousands of years after our other late-surviving relatives, the Neandertals and H. erectus, disappeared [see “The Littlest Human,” by Kate Wong; Scientific American, February 2005].