New Species of Homo Discovered: Homo naledi

It may not be the full skull but what is there is still provides a significant amount of information. For example the overall size of the brain cavity and the sloping of the skull from the pronounced brow ridge, lacking a discernible forehead and therefore a less developed frontal lobe. you could also point to the slope of the upper jaw as an indication of how far the jaw protrudes. I'm sure someone like Coyote who has studied this area of biology could get a great deal more information from this skull and how it compares with other hominin skulls.
Look again at the series of skulls that Dr Adequate posted. We see a series of 'microevolutionary' changes as the brain cavity increases in volume and other features of the skull becoming more gracile, and somewhere in that continuum lies H.naledi. If you disagree, can you point to two adjacent skulls that show what you would call a 'macroevolutionary' change?As for the hand not being convincingly human, what leads you to believe that? Like in humans the thumbs are quite large, extending as far as the proximal phalanges of the other fingers, whereas in the great apes the thumb is proportionally smaller since the metacarpals of the other fingers are elongated.

Sorry for not replying sooner, was working this weekend. Will reply to the issues on the hand the now, and discuss about the skulls in a later post. Apologies for any confusion, I realise now I should have included captions with the thumbnails I posted and been more clear in my description. The first picture is the bones of the human hand with the bones labelled which, I hoped, would make it easier to discuss the details, although I had been swithering over using the X-ray image Dr Adequate used showing the metacarpals embedded in the soft tissue of the palm. Second picture was obviously H.naledi and third was a Chimpanzee for comparison.Yes human thumbs are shorter than the rest of our fingers because of the lack of the intermediate phalanx. However, the point I was trying to make was the proportions of the bones in the hand of H.naledi is a lot closer to Humans than it is to chimps. The metacarpals of the Chimp are elongated making the overall size of their hand much longer, giving the impression that the thumb is shorter. With that in mind, can you say from those thumbnails which structures of the hand of H.naledi is more like that of Chimps than humans?

So I said I'd get to a reply on the skulls eventually... Well for the most part it is an artificial arrangement, since our current understanding of human evolution indicates that many of the species which these skulls represent branched off from our line of descent from a common ancestor we shared with Chimps. The reasoning we have for this common ancestor is the genetic evidence that Humans and Chimps are related, from simplistic DNA hybridisation to full genome sequencing, endogenous retroviruses, pseudogenes etc. Now to some, including yourself, a direct comparison between Humans and Chimps would suggest too many differences for the two species to be related, or to put it another way, for them to be related would require some ‘macroevolutionary’ change. The arrangement of hominin skulls illustrates the much smaller ‘microevolutionary’ changes that have occurred between populations leading up towards our own population. You did agree with this by stating that the skulls represented normal human variation, the only exception being skull A, the modern Chimp. However, when you look at skull B it has a lot more in common with skull A then it does with skull N.The example of the Pod Mrcaru lizards is interesting, and like you I find it impressive how much change can occur in a relatively short length of time. However, for me it increases the scope of what ‘microevolution’ is capable of accomplishing, watering down what can be described as ‘macroevolution’.I started by saying that the chart that Dr Adequate was, in one respect, an artificial arrangement. As you rightly pointed out, evolution is rarely a neat sequence of gradualism, and a more complete representation of ancestral species shows our descent to be far more complex. However, the arrangement shown was not arbitrary or chosen to support an evolutionist preconception. The ages of the skulls have already been mentioned, and although I accept you don’t accept the numerical values given, these methods do at least give an indication of the relative ages of the skulls. Also as mentioned above, study of the bones creates a catalogue of ancestral and derived features, allowing relationships between species to be identified. An example of the features which are examined can be found in RAZD’s Message 131. I also previously mentioned the size of the brain cavity, which you alluded to in mentioning nothing to indicate the relative sizes of the skulls. So here is a graph showing the transition in cranial capacity of different hominin species, with normal ranges of modern humans and chimps to the right for comparison. Edited by Malcolm, : No reason given.