Tag Archives: Origin of Modern Humans

Masters of the Planet

Yesterday I wrote about Chris Stringer’s modified version of human evolution. Today, let’s have a look at Ian Tattersall’s new book, Masters of the Planet: The Search for Our Human Origins (Macsci). Tatersall’s boo, like Sringer’s, is a good overview of the newer evidence in the constantly changing field, but he goes back earlier and provides a much broader context for human evolution. His main thesis is that the features that made modern humans unique have two main characteristics: 1) they were sufficient and causal in the process of making that one species “master of the planet” and 2) the transition to fully modern form, with respect to those features, is relatively late. Tattersall argues for a late and rather sudden development of symbolic abilities and language (I disagree with this) and seems to agree with Klein in something like a “single gene” theory describing this transition as sudden and dramatic. So, I basically disagree with his thesis, but if you want a good source to find out about the “symbolic explosion” version of modern humans, this is accessible and the documentation is pretty thorough.

Framing the Language Gene: FOXP2

You can now read the Krause et al (2007) paper from Current Biology regarding the FOXP2 variant found in Neanderthals in an open-access on-line form at Current Biology Online. Here is the summary of the article:

Although many animals communicate vocally, no extant creature rivals modern humans in language ability. Therefore, knowing when and under what evolutionary pressures our capacity for language evolved is of great interest. Here, we find that our closest extinct relatives, the Neandertals, share with modern humans two evolutionary changes in FOXP2, a gene that has been implicated in the development of speech and language. We furthermore find that in Neandertals, these changes lie on the common modern human haplotype, which previously was shown to have been subject to a selective sweep. These results suggest that these genetic changes and the selective sweep predate the common ancestor (which existed about 300,000-400,000 years ago) of modern human and Neandertal populations. This is in contrast to more recent age estimates of the selective sweep based on extant human diversity data. Thus, these results illustrate the usefulness of retrieving direct genetic information from ancient remains for understanding recent human evolution.

The authors actually get more specific regarding the role of FOXP2 in language:

Although language and speech are clearly genetically complex phenomena, the only gene currently known that has a specific role in the development of language and speech is FOXP2. The inactivation of one FOXP2 copy leads primarily to deficits in orofacial movements and linguistic processing similar to those in individuals with adult-onset Broca’s aphasia

While the paper by Krause et al is an important contribution because it involves allele-level comparison of nucleic genetic material between hominid groups and across living and extinct forms, the role of FOXP2 and the characterization of the genetics of language may be misleading, if not simply very very wrong. Continue reading Framing the Language Gene: FOXP2

British Colonialist Archaeology: More of the same?

[A repost from gregladen.com, unmodified]There is a ceremonial burial in Britain .. ceremonial because it has some red stuff smeared on bone … that has now bee dated to a few thousand years earlier than previously thought (to ca 25,000 years old).

Age of earliest human burial in Britain pinpointed from PhysOrg.com
The oldest known buried remains in Britain are 29,000 years old, archaeologists have found – 4,000 years older than previously thought. The findings show that ceremonial burials were taking place in western Europe much earlier than researchers had believed.[]

Some have suggested that this is evidence that ceremonial burial may have been invented in Western Europe rather than elsewhere. Let me tell you why that is an overstatement.1) “Ceremonial burial” is redundant. Never mind those absurd theories that for the first several tens of thousands of years people buried their dead to get rid of the smell, and not for ritual reasons. It is reasonable to assume that those that buried their dead did so for “ceremonial” or “symbolic” (whatever term you like) reasons. Today, there are people who have “ritual” behavior but who do not bury their dead. Thus, the link between burial and ritual behavior or symbolic capacity is arbitrary and not very useful. In other words, I question the premise of the question: “When did ritual behavior begin” in relation to burial per se.2) There is nothing special to separate any “gracile” population from another with respect to brains and behavior. So, if we find several instances of ritual activity associated with gracile Homo sapiens, the best guess for the minimum age for the beginning of that activity may be the beginning of the visible evidence of that species. This is highly conjectural. Archaeological evidence for a particular behavior that is concentrated in the later period of Homo sapiens would not suffice for such a conjecture. For example, the earliest evidence for the practice of agriculture is about 10,000 years old, so it would not be reasonable to argue that agriculture was a common practice before that. But, if there is evidence of a behavior linked to “ritual” scattered throughout the paleolithic. This evidence is expected to be rare to begin with, so a scattering with no clear demarcation in time could be reasonably thought of as evidence for this behavior being a species typical trait for gracile Homo sapiens. The question then arises: Do we see this behavior emerge at the origin of this species/subspecies, or does it develop shortly thereafter, or is it a behavior that existed in some for prior?3) There is specific evidence of ritual behavior some connected to burial prior to 25,000 years ago. Kebara has a Neanderthal skeleton that is a burial. Yes, it is true that some researchers have suggested that this is not a burial, but they are in my opinion wrong about this. We can discuss this at another time if you like. For now, I’ll just say that Kebara is a nearly complete skeleton, with only a few bones missing some of which (the lower legs/feet) were clearly removed by previous excavators using crappy excavation techniques, and the head removed probably in antiquity, some years after the burial itself happened. (One mastoid process of the skull is intact, the rest of the cranium gone). This burial is about 65,000 years old.In Southern Africa and elsewhere there are a number of other objects with red stuff (ocher) spread on them, or that otherwise suggest symbolic/ritual behavior, dated to roughly the same age (at least in terms of order of magnitude) as Kebara.There is evidence that gracile Homo sapiens existed at just under 120,000 years ago in Southern Africa, and there is evidence of other “modern” behaviors, in terms of food gathering and lithic technology, dating back much farther in time.So, in my opinion, the new British date is cool, but it is primarily a moderate yet important adjustment to the existing data set. It does not change our thinking about anything except the local sequence for Britain.