Shedding Light on Early Homo

This week, the news of new fossil finds northern Kenya hit the anthropological scene.  You can find a good summary by Kate Wong here, and at Hominid Hunting here.  For further, bloggy, but knowledgeable commentary, check out Adam Van Ardsdale's post.  These fossils have special importance because they fit into the time period just around two million years ago, which marks the beginning of our genus, Homo, and has been characterized by a relatively fragmentary fossil record.

Toddlers, Tarsiers and Teeth

I just returned from taking my two small sons to the dentist.  By the way, if I had known the costs of something like dentistry before having kids...I don't know if they'd be here now. 

This visit marked the first time my four year old had x-rays taken. When we viewed the images, I was struck by how much his mandibular incisors (bottom front teeth) looked like that of a prosimian dental comb. Primates are noted for their lack of dental specialization (to take advantage of varied and flexible food sources), but the dental comb is a classic example of some specialized dentition that does occur in non-human primates.

Despite the adaptive specialization found in dental combs, I still found the common ancestry apparent.  My son and a lemur may look very different now, but that x-ray reminded me in a visceral way how they do share grandparents from about 50 million years ago.

My oldest son

Human Mandibular Incisors, not my son (disregard B and C)

Lemur Dental Comb (also mandibular incisors, plus modified canines)

Not my son