So, Homo longi. It's such a good name. Dragon people. And an amazing skull discovery. Adds to our knowledge of the Middle Pleistocene in China. But it's sad that the name is not going to stay.… Harbin skull viewed from the front. Photo by Wei Gao, from T
The boring reason why we can't use the Homo longi name is technical. The research puts the Harbin skull together with the Dali skull, and Xinzhi Wu gave that the name Homo sapiens daliensis more than 40 years ago. So IF there's a species, it has to be H. daliensis. Phylogenetic morphology analysis of Harbin skull, showing it
In case you wonder how close Harbin looks to Dali, here is Harbin on the left and Dali (which has some crushing to the maxilla) on the right. As Weidenreich might have said, they resemble each other as closely as one egg resembles another. Harbin skull (left) compared with Dali skull (right)
But technical problems are unsatisfying. The real question is whether the Chinese later Middle Pleistocene record represents a lineage, and whether we should consider such lineages, like Neandertals, as species. Are Homo daliensis and Homo neanderthalensis the right way to talk? Museum reconstruction of a Neanderthal male adult with a wom
This is a deep problem upon which scientists have diverse opinions. I think that this new research on the Harbin fossil offers a window to a clearer future. Let's take a close look at that phylogeny, the one that places the Chinese MP fossils close to African H. sapiens... Phylogenetic hypothesis presented by Ni et al. 2021, showing
The actual branch patterns are fascinating. H. antecessor groups with the Jinniushan-Dali-Harbin-Xiahe clade. Neandertals are an outgroup to these and moderns. Modern humans and H. antecessor are sister clades to the exclusion of Neandertals! It's nuts! Phylogenetic hypothesis in Ni et al. 2021, same repeated thr
Now, we have learned a few things from DNA and ancient proteins. H. antecessor is a sister of the Neandertal-Denisovan-modern clade. Neandertals, today's humans, and Denisovans share common ancestors around 700,000 years ago. Neandertals and Denisovans were related. Tree showing relationships of Denisovan, Neanderthal, modern
All known archaic groups with ancient DNA evidence interbred. Repeatedly. Seemingly every time they came into contact. Three distinct groups of Denisovans, all known from their ancient interbreeding with modern people. So. Much. Interbreeding. Timeline showing archaic human lineages together with depict
We have the interesting question of whether the Harbin skull is a Denisovan. Dali, Jinniushan, Hualongdong, all Denisovans. Good hypothesis. Could be true. Knowing the answer, though, is not essential to the basic problem, which is: Morphology and DNA here are inconsistent. The Harbin phylogeny tree once again, from Ni et al. 2021. I
There is no way to make this tree match what we know from DNA and protein. Neandertals are in the wrong place. H. antecessor is in the wrong place. Heck, even Liujiang and ZKD Upper Cave seem like they're in the wrong places. Morphology and DNA are inconsistent. Harbin phylogenetic analysis once more, from Ni et al. 2021
It's not a question of DNA being right and morphology being wrong. They just tell us about different things. Morphology tells us about adaptation, convergence, and retained features from deep ancestors. DNA tells us about phylogeny, incomplete lineage sorting, and introgression. Neanderthal in suit, at Neanderthal Museum.
So are they species? I think that the appearance of morphological distinctiveness between these human groups is mostly a result of poor sampling. This new research shows that as we increase the sample, our picture gets blurrier and less likely to match DNA evidence of phylogeny. Blurry Neandertals
We still have much to do to understand why lineages retained some genetic differentiation for hundreds of thousands of years, and we may yet find that speciation mechanisms such as fitness costs of hybridization may be a part of the explanation. But we're not there yet. Neanderthal skulls in red. Wired

• • •

Missing some Tweet in this thread? You can try to force a refresh

Keep Current with John Hawks

John Hawks Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!


Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @johnhawks

24 Jun
The new report of fossil material from Nesher Ramla, Israel, claims a "previously unknown archaic Homo population" some 140,000 years ago. It's a big claim in an area where most scientists have thought that early modern humans and Neandertals interacted.… Mandible from Nesher Ramla. From Hershkovitz et al. 2021 htt
Looking at the morphology of the mandible NR-2, it falls within the variation of fossils attributed to Neandertals, and is similar to Krapina, which is around the same age, and Sima, which are early Neandertals. This seems like a basic early Neandertal jaw. PC plot showing position of Nesher Ramla 2 next to Neanderta
The other fossil NR-1 is a complete right parietal bone and fragments of the left parietal. The analysis of shape places is near late Neandertals and early Neandertals, but a bit less "barrel-shaped", thereby similar to generalized H. erectus and African Middle Pleistocene Homo. PC plot of Nesher Ramla 1 parietal bone showing its position
Read 11 tweets
23 Jun
Today, I'm reflecting on how this reporter was betrayed by her @nytimes editors. The reporting turned up so many newsworthy ledes, and instead they let it tailspin into a tuna Zoomer fluff story that spreads basic science misinformation.…
@nytimes For instance, "a handful" of commercial food testing labs refused to take the @nytimes samples. They all said (accurately!!) that the technology wouldn't give an answer. Why is this not the lede in a story that is really about the challenges in sourcing food ingredients?
@nytimes We have just gone through a year in which PCR testing has been a major news story. Understanding what it is, its strengths and limits, why it was so hard to get right, is pretty important. COVID testing brought down a President. So why does this story fumble PCR so badly?
Read 8 tweets
19 May
Classic paper: "Biology and Body Size in Human Evolution: Statistical Inference Misapplied" Richard Smith (1996, Current Anthropology) works through examples to show how mistaken ideas about extinct species can arise through estimation of body mass.
"[A]s of today, many inferences about fossil hominids are being made on the basis of body mass alone, and the range of uncertainty is being mostly ignored." This problem remains 25 years later.
"Finally it must be reemphasized that all of this discussion does not apply only to body mass. With the growing interest in life-history, the potential misuse of traits such as molar eruption age, sex dimorphism, and cranial capacity is clearly on the horizon."
Read 4 tweets
19 May
"A new dating program using the isochron method for burial dating has established an absolute age of 2.22 ± 0.09 Ma for a large portion of the Lower Bank, containing the earliest Oldowan stone tools and fossils of Paranthropus robustus in South Africa."… SKW 12 maxilla, from Kaszyc...
If this date is accurate, it places a good Oldowan assemblage into a temporal context where it's not clear Homo was present at all. These are Paranthropus or Australopithecus tools. Swartkrans quartz cores fro...
Only 2 fossils from Swartkrans Lower Bank can be excluded from Paranthropus: an isolated molar fragment and a juvenile mandible fragment, SKX 21204. The unerupted premolars of this otherwise super fragmented specimen are interesting. SAHRIS image of SKX 21204 m...
Read 9 tweets
7 May
Anthropologists of the 1990s often did pygmy marmoset-to-gorilla regressions across primates to "predict" all kinds of things about extinct hominins. We don't teach this anymore, but the resulting myths are tenacious. One of those is "Dunbar's number".…
The idea was that brain size limits the number of social relationships you can have. Dunbar took a cross-primate regression of group size and brain size, and plotted humans. He surmised that the human brain should max out at around 150 social relationships. This isn't right.
Psychologists ran with this idea, trying to find all kinds of ways that 150 might make sense. But people are pretty variable in how they apportion their social lives. That didn't stop Silicon Valley types from encoding "Dunbar's number" into their social media worldview.
Read 6 tweets
6 May
I'm concerned about the narrative I've been seeing about burial. All current and recent cultures have had some form of mortuary practice. To dig a hole, place a single intact body, and cover it up is only one pathway among a wide spectrum.
There is nothing about this burial pathway that is more "human", or more demonstrative of "symbolic culture", or "higher" than others. Communal burials, catacombs, creches, skull curation, sky burial, ritual cannibalism, and mummification are all human.
Single body burial is presently widespread around the world, and this owes much to traditions rooted in Islamic, Christian, and Jewish heritage, coupled with colonial and industrial economies. Burial marks status even in geographic regions where it was not historically practiced.
Read 7 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!

Follow Us on Twitter!