Close your eyes and imagine Africa as it would have been 1.6 million years ago. The sun radiating in the sky, the fish swimming in the marshes, the-

wait, whoa, huh? marshes?

That's right. Marshes. An examination of sediments at Nariokotome in Kenya show that the area was a floodplain. For quite a while. It wasn't always the dry, dusty image with coke bottles falling from the sky we see in the movies. Rather, it was humid. It supported lush green life which sheltered lizards and young fish among reeds in shallow water. When the Omo River overflowed, Nariokotome sprang with life.

It was then, in that lush setting teeming with aquatic life that a young boy lived and died. He was much like the Masai people that inhabit Kenya today, with long, slender limbs that helped him survive in the African heat. He had a bone structure that allowed him to walk and run with a grace that would make Olympic Gold Medallists weep. He also had an infection from gum disease that led to his death at the young age of 9 or 10.

His body came to rest in a place near Lake Turkana amongst greenery, so it's fitting that 1.6 million years later it would be the growth of life that reintroduced him to the world. A mesquite tree took to seed and began to grow from the fossilized cranium of the boy, slowly bringing fragments of bone to the surface. In 1984 those fragments were found.


-The discovery-
In the 70s Africa was at the center of the world's stage as the Leakey family made one discovery after another at Olduvai Gorge. Then things trickled to a stop. By the 80s it was believed Africa had been picked dry, that nothing of significance would be found there. But Richard Leakey along with wife Meave and their friend Alan Walker believed otherwise. In 1984 they assembled a team of experienced fossil hunters and sought out the fragments that only their trained eyes would see. The leader of the hunters, Kamoya Kimue, was the first to make a discovery.

Kimue found small pieces of a hominid skull. This was all that was needed to put the rest on the scent, carefully scouring the area in search of the remaining fragments and bones. What they ended up with - after four years of excavation - was the nearly complete skeleton of what appeared to be a 12 year-old boy.

wait. didn't you say he was 9 or 10?

The most complete Homo erectus skeleton ever found, Turkana Boy (as he was dubbed) was only missing the hands and feet along with one humerus. A quick look at his mandible showed he'd just received his second molars. This is consistent with a human around the age of 12. However, when they looked at the growth lines on his teeth they saw that Turkana Boy was actually only 9 or 10. This meant that he matured quickly.


-What else do the bones say?-
Turkana Boy's skeleton tells an interesting story. His small molars indicate he was omnivorous, no longer needing the large teeth to grind plants and nuts. Coupled with his long limbs and a height that would have put him at 6' as an adult, we can surmise that he probably scavanged meat after traveling long distances. The neck of his femur is longer than in modern man, providing a better range of mobility. He also had extra vertebrae and thicker femur bones which provided more support for his frame than we experience today.

why is that?

The pelvis of Turkana Boy is quite narrow, which suggests that infants were born with small brains that grew rapidly after birth. In order for our species to evolve from the 900cc brain that Turkana Boy had to the 1350cc brain we now have, the pelvis had to widen. We lost the extra vertebrae and thicker femurs with their long necks to make room for babies with a larger capacity to learn and the ability to speak (something it's thought Turkana Boy may not have been able to do since the opening his spinal chord would have occupied in the vertebrae is small). In short, for bigger brains we have to endure some limits in our bipedalism as well as lower back pain.


-The ramifications-
Turkana Boy's discovery came at the height of the creation vs evolution battle. Before he was found many people sat on the fence concerning the matter for a lack of evidence. When the first nearly complete skeleton of what is clearly a human was discovered, and then was dated to 1.6 million years in age, many people fell off the fence.

At the same time some scientists were unsure of whether it should be classified as Homo erectus or not. It had all the right developments and characteristics to be classified as such, but it had some differences as well. The unusual extra vertebrae, the thick femurs with their long necks, made some think perhaps it should be considered a new species. Despite his firm belief that Turkana Boy is, in fact, Homo erectus, Rickard Leakey eventually went with the classification Homo ergaster. To this day Turkana Boy is referred to as Homo erectus/Homo ergaster as the line between the two is pretty thin.


References:
Talk Origins, www.talkorigins.org/faqs/homs/15000.html
Searching for Our Origins, www25.brinkster.com/jmcginn/homo_erectus/ knm_wt_15000/knm_wt_15000.asp
The Lake Turkana Boy, www.mc.maricopa.edu/dept/d10/asb/learning/ origins/hominid_journey/turkana.html
What Bones Tell Us About Human Evolution,
www.saitama-kenpaku.com/jinrui/special/ english/number/07_E/factor05_02.htm
Africa, www.homepages.hetnet.nl/~krocat/english/afr_cont.htm

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