A hint of the social behavior of early Homo erectus comes from the earliest known #hominin to survive with near total loss of teeth, 1.8 million years ago. Some wild primates also survive years with little functional dentition. #paleoanthropology#FossilFriday
For years, anthropologists have looked at the survival of older people with tooth loss as a possible indication of social caring, empathy, and value of tradition and knowledge to social groups—once with Neandertals, more recently with H. erectus. #paleoanthropology
Some have criticized inferences about social care in these human relatives, by pointing out other primates that sometimes survive. This wild chimpanzee skull in the collection of the @goCMNH is a great example, with loss of all but one molar and premolars.
But all this does is show that sociality is important to survival with disability outside of hominins. Our lineage is not uniquely social—many elements of hominin social life are shared more broadly across social mammals including primates.
We do learn about humanity by working to understand the lives of exceptional individuals in the past. Sometimes the humanity we learn about is that part we share with other species.
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Out of yesterday's Neandertal ancestry-oriented papers, I am more focused on the Zlatý kůň analysis. The history of thinking about this partial skeleton and the way this paper changes that thinking has much to reveal about this moment in the science. doi.org/10.1038/s41559…
The Zlatý kůň skeleton was discovered in 1950 when a nearby limestone quarry blasted an opening into a previously unknown cave system. The skeletal remains and many artifacts were within a debris cone from a chimney going higher into the cave. doi.org/10.1007/978-1-…
From the beginning, it was unclear whether the skeleton and artifacts were associated. All appeared to have entered accidentally, falling from chambers above. This was not an occupation site. The human remains emerged over several excavation seasons.
The MH2 #hominin mandible is still being built, fragment by fragment, as pieces are recovered from Malapa and prepared in the lab. The skull of this adult Australopithecus sediba individual may be found within the breccia as well. #paleoanthropology
If you're following this series of illustrations, you may recognize that MH2 is my first repeat, as I earlier featured the MH2 pelvis. The Malapa skeletons are amazing examples of discovery, as each piece emerges from the site, it allows us to test new hypotheses.
Some scientists claimed that the difference between MH1 and MH2 mandibular ramus shape must mean that one is Australopithecus and one Homo. Ritzman and coworkers (2016) examined this, finding them compatible with normal within-species variation. dx.doi.org/10.1016/j.jhev…
Some say MSA/Middle Paleolithic hominins used ochre for sun protection, blocking any conclusions about marking or other symbolic uses. I say traditions of processing and using mineral pigments for sun protection are more complex and less universal than cosmetic uses.
Some archaeologists have focused on cosmetic uses of pigments, but it remains much more common to see ochre and other pigments framed in terms of "symbolic marking" or "marking".
Of course, cosmetics are used for symbolic marking, and also other kinds of marking, and much use of cosmetics across cultures is directed toward mimicry, enhancing the visual impact of features, or reducing the visual impact of features, not "symbolic" in a strict sense.
So, I've started tracking down the citations in this Magnetodeth paper. It will be a surprise to no one that the papers on genetic bottlenecks do not support the 42,000-year-ago event that the new paper says they do.
For example, the paper claims that thylacines underwent a bottleneck 42,000 years ago, citing Lauren White et al. 2018 doi.org/10.1111/jbi.13… That paper actually says 20,400 years.
In the Australian case, the cited papers note that extinctions had a regional pattern that began by 48,000 years ago, the number 42,000 refers to a particular Bayesian analysis and not actual last appearance dates (which are more dispersed) doi.org/10.1038/s41467…
One way of casting this lack of knowledge is to say maybe there was no "origin", that we are looking backward through a cloudy lens at a gradual mixing process that never had a beginning. This idea comports with what we know about continued Neandertal-African mixing.
Yet with Neandertals we intently focus on mechanism: "How much mixing happened, on how many occasions, and how much did it matter?" Surely this must factor into the way we look at evolution within Middle Pleistocene Africa also. With more data, we will focus on those questions.
Lactase persistence and dairying on the surface seem to be a simple and compelling example of gene-culture coevolution in humans. And yet there are patterns that confound the simplistic story. I appreciate that @Maddy_Bleasdale et al discuss some of those. nature.com/articles/s4146…
Several aspects of lactase persistence genetics are not being covered well by press accounts of this paper. Journalists have gone with a pretty simple "counterintuitive lede", i.e., people were drinking milk before lactase persistence mutations were common.
A look at the great frequency maps in the paper is enough to remind folks of the reality that most lactase persistence-associated alleles *still* aren't very common. They have frequency maxima of 2-5% today and are highly localized.