Homo floresiensis News

According to Yahoo News a new study is being published in Biology Letters that performs a meta analysis of all studies of primates in relation to island dwarfing:

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A New Human: A Book Review

A New Human: The Startling Discovery and Strange Story of the “Hobbits” of Flores, Indonesia by Mike Morwood and Penny van Oosterzee is scheduled to come out in May, 2007. Through the miracle of internet blogging I have a review copy.

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Tis a Puzzlement: More on Homo floresiensis

Like Carl Zimmer, I think I have come down with a case of Homo floresiensisitis. The more I hear about it the more puzzled I become. Let’s start at the beggining of my current befuddlement with the issue. Some of you may remember This post of Carl’s, about Gert van den Bergh’s theory that the hobbit was quadrupedal. The argument was based on the amount of humeral torsion present on the fossil. What is humeral torsion you ask?

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Homo floresiensis: More Pieces of the Puzzle

The past week has seen a flurry of activity concerning Homo floresiensis. Starting with an article in the letters section of Nature (kindly sent to me by Aydin at Snail’s Tales)and continuing with articles in Nature’s News and News and Views Sections. Several bloggers have posted on it as well. Carl Zimmer at Corante has an interesting post on the subject. Orbis Quintus has some interesting thoughts as well. Perhaps, the most interesting though, is Hawks here, here and most importantly here.

My first thought on seeing the pictures of some of the other bones discovered was “Wow, they are really robust” but I’ll get to that later. The main article (“Further Evidence for Small-Bodied Hominims from Late Pleistocene of Flores, Indonesia”) gives some details on the stratigraphy of the cave where the fossils where found – including spots where samples for thermoluminescence were taken, talks about the tools and faunal remains and provides a table listing the remains that have been recovered so far. There is a new mandible (LB6/1) that is slightly smaller in size than the original. More importantly, there is some post cranial material. Which is were things really get interesting. As I mentioned above, the post cranial material is robust. The pictured bones are compared with similar bones from a human pygmy and the differences are noticable. For example, the humerus has a greater (midshaft circumference wise) as does the recovered tibia. The humerofemoral index (a ratio comparing the lengths of the humerus and femur) is the same as for AL-288-1 (Lucy) and the blades of the pelvis are flared antero-laterally which implies an australopithicine shaped thorax (and hence indicates some climbing behavior). Because of this the authors of the paper have moved away from intepreting H. floresiensis as a dwarf H. erectus. After reading the paper and seeing the pictures I would have to agree. For example, the trochlea and capitulum of the humerus look a lot like Australopithecus robustus – TM 1517 or KNM-ER 739 for example. One other interesting feature was the humeral torsion (rotation of the head of the humerus relative to the plane of the distal end) which is in the range of gibbons and macaques. Humeral torsion occurs mainly when there is a laterally facing shoulder joint and it is necessary for the elbow to flex and extend in an anteroposterior plane. Humans and the great apes have a large degree of humeral torsion (although gorillas, the most ground dwelling, have the least amount of the three). Overall, what the morphology says to me is that this is something new and we need to interpret it in it’s own right rather than trying to force it into current species.

Perhaps, the saddest part is that the researchers have been denied permission to return to Liang Bua.

Cave Bear DNA and Homo floresiensis

Cave Bear Skull Posted by Hello

In a previous post I mentioned that a large segment of the Cave bear genome had been sequenced. I also mentioned that the researchers responsible for sequencing the cave bear DNA were planning on trying the same techniques on neanderthal DNA. Well, there is a new wrinkle:
Homo floresiensis Posted by Hello

Another possibility is to apply these techniques to the remains of Homo floresiensis, found recently in Indonesia. Researchers nicknamed this human ancestor “the hobbit” because of its tiny stature. (See pictures of the hobbit.)

H. floresiensis is believed to have diverged from modern humans two million years ago. Neandertals may have diverged from humans 500,000 years ago.

The successful DNA sequencing of the two human-ancestor species could help scientists describe the evolutionary events that led to modern humans.

afarensis doesn’t think this will happen soon, neanderthals will be first and if the techniques are successful then it will be extended to Homo floresiensis (which is actually within the correct time range).

Homo floresiensis

The April issue of National Geographic has an interesting article on Homo floresiensis. The article is written by Mike Morwood, Thomas Sutikna and Richard Roberts. The basics of the find are covered (who, what, when, where, etc)and brief mention is made of the microsephaly issue, but the find is presented as legitimate. They cover other issues such as island dimorphism and provide some interesting info concerning the archaeology of the site. This may be intersting.
A second article, by Josh Fischman, covers finds of Homo erctus at Dmanisi, Georga. The main emphasis of the article is on one of specimens that was toothless. More importantly, the mandible shows signs of bone resorption – indicating the individual survived after loosing his teeth. In this respect this find is similar to finds of later neanderthals. The author also discuss the spread of H. erectus out of Africa, and of course, links it to the H. floresiensis finds. One of the more interesting pieces of information in the article is that the Dmanisi fossils were smaller than the african or asian erectus specimens (excepting H. floresiensis). Height is around four and a half feet and cranial capacity averaged 650 cc’s. Some traits displayed by the four skulls are similar to H. habilis and one of the discovers, David Lordkianidze, is quoted as saying “… this is something between habilus and erectus, and maybe it’s the founder of erectus”.

Interesting, I really need to get to a library and catch up on whats been happening in the world of Paleoanthropology.