The press is running some mouth watering news on an upcoming Nature paper that provides ‘a new, simplified family tree of humanity.’ I’m really interested in this topic, especially figuring out just how bushy our phylogeny is. See, there has been what I consider misguided movement growing within hominin systematics. One where features from a small sample size of fossils has lead researchers to consider them unique enough name lots of new species, all under the guise of diversity. The only ‘success’ this movement has had has been in complicating the evolutionary history of humanity.
I’m extremely concerned about this problem because not only does it make teaching and explaining human evolution more challenging, but also raises ethical concerns if people are just naming new species to make a name for themselves. Often times that stuff gets weeded out in critiques and reanalysis, but there are so many different species names floating around that it is hard for anyone not verbose in hominin nomenclature to figure out who’s who.
All that being said, I hope you realize that reading any new approach to simplifying human evolutionary history will be extremely refreshing. I’ve tried to track down the paper in Nature‘s advanced issue section, but it ain’t there yet. Soon, I hope. In the meantime, all we have to review is the AFP release on the topic.
The lead author is Rolando Gonzalez-Jose, from the Patagonian National Centre at Puerto Madryn, Argentina. It seems like the thesis of this paper is that facial traits do not appear out of the blue but result from continuous change. Ahh, sounds like a punctuated equilibrium debate. He argues that, specimen that have relatively minor changes in features as compared to others should not be automatically held up as representing a new species. Well, no duh.
In order to establish this, Gonzalez-Jose used a new analytical approach on 3D images of 17 hominid species, with a gorilla, chimp and modern human thrown in. The approach focused in on measuring the similarities and differences on a particular set of fundamental yet long-term changes in skull shape. Using computational methods, the skulls were compared on four variables,
- The roundness of the skull
- The base of the skull
- The protrusion of the jaw
- The facial retraction, or in other words the position of the face relative to the cranial base
Organizing the outcome of the measurements into a phylogenetic tree, reportedly reveals a clearer view on the evolutionary history of humans and their ancestors. Some conclusion reported are messages we’ve read time and time again, such as this one result: Neandertals are declared “chronological variants inside a single biological heritage.” Again, I don’t have the paper, so I’m going on what was said in the press release.
It should be noted that the source can’t spell ‘phylotogenic’ correctly. I don’t know if that’s any indication on how trustworthy this report is because I know I have a lot of typos and grammatical mistakes here, but I’m not full time reporter. As a professional news outlet, I expect them to catch mistakes like that when reporting science.