Scientific Methods

Saturday, March 11, 2006

IS TURKANA BOY HOMO ERECTUS OR HOMO ERGASTER?

"Turkana Boy was found by Kamoya Kimeu in 1984 at Nariokotome near Lake Turkana, Kenya. The skeleton was almost complete and represented an 11-12 year old boy – the only skeletal parts missing were hands and feet. The skeleton was 160 cm tall with a brain (cranial capacity) of 880 cc reach 910 cc when adult indicating that skull was fairly different to modern humans but the body was surprisingly tall and modern for a fossil 1.6 million years old. small differences. The most striking differences in the skeleton between Turkana Boy and ourselves is that the holes in his vertebrae, through which the spinal cord goes, have only about half the cross-sectional area of ours. This has interpreted as modern humans need for fine motor control in the thorax to control speech and consequently he would probably not have been fluent in speech. His classification into either Homo erectus or H. ergaster depends on whether you recognise the difference between the Asian and African members. This is what Wikipedia has to say
Homo ergaster ("working man") is an extinct hominid species (or subspecies, according to some authorities) which lived throughout eastern and southern Africa between 1.9 to 1.4 million years ago with the advent of the lower Pleistocene and the cooling of the global climate.


Homo ergaster is sometimes categorized as a subspecies of Homo erectus. It is currently in contention whether H. ergaster or the later, Asian H. erectus was the direct ancestor of modern humans. H. ergaster may be distinguished from H. erectus by its thinner skull bones and lack of an obvious sulcus. Derived features include reduced sexual dimorphism, a smaller more orthognathic face, a smaller dental arcade, and a larger (700 and 850cc) brain. It is estimated that H. ergaster stood at 1.9m (6ft) tall with relatively less sexual dimorphism in comparison to earlier hominins. Remains have been found in Tanzania, Ethiopia, Kenya, South Africa.”


If you looked at the notes posted previously on this Weblog you will see that there is debate on this issue and it revolves around how do we define what a species is when we only have the fossil evidence? We will debate the species concept in the Biodiversity Course (BCB705), but even with living material and access to analysis of the genetic material it can be difficult. We need to realize that Science is not absolute, it changes depending on new evidence and personal interpretation. This is one of our intentions of this course to help you become informed and to construct your own opinions based on scientific evidence.

Finally thank you for raising this issue, and I hope this helps, if you have more comments please add these to the Weblog so we can all share in the questions and the responses.


A very useful reference to Turkana Boy is
http://jan.ucc.nau.edu/evc/Bahn_Turkana%20Boy.pdf


To add a bit more confusion – here is an interesting article about Homo erectus or H. ergaster and some other fossils both in Africa and Europe.
http://www.sciencemag.org/cgi/reprint/300/5621/893b.pdf


Finally a resource you might find use its a sort of FAQ for "Human Origins"
http://www.talkorigins.org/pdf/fossil-hominids.pdf

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