Translate

Guide to Patagonia's Monsters & Mysterious beings

I have written a book on this intriguing subject which has just been published.
In this blog I will post excerpts and other interesting texts on this fascinating subject.

Austin Whittall


Showing posts with label modern human. Show all posts
Showing posts with label modern human. Show all posts

Thursday, April 2, 2026

Oldest Homo Sapiens Sites in the Old World


The map below caught my attention while reading a new article by Zhang et al., 2026 it shows the oldest sites where Homo sapiens remains have been found.


Two things surprised me: (1) Despite Africa being touted the "Cradle of Mankind", 40% of the sites over 100 ky are found in Eurasia. (2) Of the 50 to 30 ky sites, 3 are found in Africa, and the other 14 are in Eurasia and Australia. Of course, the map shows partial information, so there are more sites in Africa, but it is suprising to notice such a prevalence of sites outside of Africa.


Fig. 1. Examples of early H. sapiens fossils older than 100 ka (red circles) and younger specimens dating to 50–30 ka ago (yellow circles) in Africa, Eurasia and Oceania. Fig 1 from Zhang et al., 2026

The oldest H. sapiens fossil outside of Africa is from the Greek Cave of Apidima where Apidima 1 skull was found (210,000 years old); see Harvati et al. 2019.


The second oldest is the 190,000-year-old jawbone from the Misliya Cave in Israel, reported by Hershkovitz et al, 2018.


The oldest African site is the Irhoud, Morocco, reported by Hublin et al, 2017, and dated to 315±34 kya. However these hominins have a mix of archaic and modern features that make some scholars wonder if it is a human or another hominin: "[They] have a facial morphology very similar to extant H. sapiens, as well as endocranial volumes that fall within the contemporary range of variation. However, their braincase shapes are elongated rather than globular, suggesting that distinctive features of brain shape, and possibly brain function, evolved within H. sapiens." (Scerri et al., 2018).


The next two African specimens are equal to, or younger than the Eurasian specimens!: Both from Ethiopia, the 195,000-year-old remains from Omo Kibish, and 160,000-year-old bones from Herto. A 2022 paper pushes the dates further back in time to ~230 kya. However, note that they may not be modern humans at all: "The Herto hominids are morphologically and chronologically intermediate between archaic African fossils and later anatomically modern Late Pleistocene humans. They therefore represent the probable immediate ancestors of anatomically modern humans. Their anatomy and antiquity constitute strong evidence of modern-human emergence in Africa." (White et al., 2003).


What is Anatomically Modern Human?


The key issue in my (layman's) opinion is that there seems to be no clear definition of what an Anatomically Modern Human is. Someone who looks like us even though they may not yet have developed behaviors similar to ours.


With a handful of deformed and partial remains (a pice of jaw here, a skullcap there, a few teeth over there) it is impossible to decide if those people who differ from us, and also between themselves, are the norm, or probably outliers of populations that had large intra-population variability.


Does a globe-shaped skull imply more homo-sapiens-similarity than a human-like jaw? Where is the line? Does an oblong skull like the ones found in Morocco count as humans or not? A mossaic of features is human? or primitive? What do archaeologists think about this?


We know that brain size evolved in homo species, and this growth influenced the shape of the skull as different areas of the brain developed, pushed by genetic changes and natural selection. More complex cognitive abilities appeared, the stone tools used by homo individuals gradually changed, improving, becoming more efficient in the use of knapped stone. Acheulean tools of erectus were used for over 1.5 million years, unchanged. Then came Mousterian, Levallois and microblades in a faster sequence of improvement mirroring the changing behavior of our ancestors. The discovery of fire, clothing, use of bone, wood, complex tools, needles, fishooks, symbols engraved on small objects, rock art, burials, all reflect behavioural growth as brains developed.


This evolution led from small skulls, with slanted faces, massive jaws, no chins, heavy browridges, to current gracil, rounded skulls, chins, and high forehads over flat faces.


Is there a sharp line between Modern Humans and "the rest"?


Pearson, 2008 looked into this matter in a detailed paper that ponders the archaic and modern morphology, the reasons for variability (evolutionary adaptation, genetic drift, and the shortcomings of the statistical and biological approaches to the subject.


human and Neanderthal skull and brain

A very interesting research article by Simon Neubauer, Jean-Jacques Hublin, and Philipp Gunz, 2018, analyzed the shape of the skulls and brains, as well as their size. Contemporary human beings have globular (balloon-shaped) brains with an upright forehead and a prominent parietal, the area occupied by the cerebellum is larger and rounded. Or faces are flat. On the other hand, the homo people before us had slanting faces, and elongated brains. (see image comparing a Human and a Neanderthal skull and brain, from Fig. 1 in the 2018 paper above. The authors compared different parameters of brains and skulls of Homo erectus, Neanderthals, and "Humans" from three periods: (1) very early specimens (200-300 kya) from Morocco and Ethiopia, (2) later people from the Middle East and East Africa (100-130 kya), and (3) more recent humans 35-10 kya. The images below show how they align using Principal Component Analysis:


PC1 PC2 comparison homo skulls
Fig. 2 bgPCA of endocranial shape (top) and Fig. 4 bgPCA of endocranial form (bottom). Arrows show the Evolutionary trends of shape changes in archaic and modern individuals are shown as regressions on geologic age. Simon Neubauer, Jean-Jacques Hublin, and Philipp Gunz, 2018

Clearly, there is an evolution from primitive to modern features, with group (2), which included these samples: three from the Levant, Skhul V, Qafzeh 6 and Qafzeh 9 ages 115 ky, and one from Africa, the Ngaloba LH 18 skull from Laetoli, Tanzania (120 kya), closest to moderns and group (3), the latter aged 10 to 30 kya, have brains and skulls that are definitely modern.


Even Anatomically Modern Humans, as they dispersed across the globe following the OOA events carried different skull shapes that can still be identified in contemporary people, and have been used to suggest two migrations and two routes into Eurasia (the "two layer" hypothesis). One comprising Papuans and Oceanians following a South Asian route shares elongated skulls with Africans, the other across Central Asia into Siberia, Europe and East Asia has globular skulls, Europeans have compact jaws, Native Americans and NE Asians share large skulls, higher faces and cranial vaults with tighter foreheads (see Matsumura et al., 2022 and Matsumura et al., 2019).


Even modern humans carry introgressions that modified their skull shape (Neanderthals), as reported by Goovaerts et al., 2025, which has added diversity to non-Africans. Human chins are linked by genes to the flatter face of Homo sapiens. Reearch by Schuch et al., 2025 found that slower and shorter growth after birth, and bone reorption during childhood is a distinctivly human feature, found in all modern humans and absent in Neanderthals, that leads to gracile faces lacking Neanderthal prognathism (jaw protrusion).


Scerri et al., 2018, discusses and questions the orthodox notion that modern humans evolved and emerged within one single, specific population located in a particular region of Africa. The paper aruges that fossils from the early days of humans are very different, and the genetic evidence pointing at a very deep and ancient population structure within Africa (I have mentioned this in other posts, involving isolation, small groups, archaic interbreeding and mutation rates that are different to non-Africans) also supports a multiregional origin involving separate populations, an "African Multi-regionalism."


These isolated popualtions in different environments evolved separately at different paces, and this would explain why they show a combination of archaic and modern traits (they were boxed off in different regions of Africa by very dry deserts and dense tropical jungles —n mountains or glaciers in Africa— and faced different environmental challenges). This article also puts forward some unanswered questions and suggests directions for future research:


"Resolving the speciation of H. sapiens and the character of ancestral populations represents a crucial first step in understanding the emergence of the morphological features that diagnose our species during the later Middle Pleistocene
...
Finally, were some of our anatomical traits inherited from transitional African forms before they became extinct? The range of dates for H. naledi and H. heidelbergensis confirms the late survival of at least two archaic species in Africa. The size and environmental diversity of Africa, particularly the poorly investigated forested regions, may have permitted the late survival of more archaic species as well as of early forms of H. sapiens. These discoveries have fuelled speculations that H. sapiens may have interbred with archaic species in Africa itself. Distinguishing admixture between species from the reintegration of diverse H. sapiens lineages represents a major challenge, with significant taxonomic implications.
...
while a globular braincase does seem to represent a synapomorphy of extant H. sapiens, can it be effectively characterized for application to the fossil record? We emphasize that H. sapiens is a lineage with deep and likely diverse African roots that challenge our use of terms such as ‘archaic H. sapiens’ and ‘anatomically modern humans’. Unless they can be operationalized with more clearly defined traits, such categories will have declining value. Diagnostics of H. sapiens must reflect trajectories of evolution rather than static views of our species – which has changed, and continues to change, at various scales.
"


Into Africa


I believe that it is possible that the homo group leading to Modern humans probably evolved in the Middle East, and moved into Africa from there. However, this notion is contrary to what science believes is the correct approach to our ancestry, and outlined above by Scerri et al. I have the feeling that Chinese scholars will continue their push to have humans appear and evolve in Eastern Asia. Future publications and research will show us how these ideas develop.



Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2025by Austin Whittall © 

Sunday, April 5, 2020

Homo antecessor and its relationship with Neandethals, Denisovans and Humans


Covid-19 is disrupting the lives across the world with its path of sickness and death spreading globally. But science continues. Today I post about an article published in Nature this week: Welker, F., Ramos-Madrigal, J., Gutenbrunner, P. et al. The dental proteome of Homo antecessor Nature (2020). https://doi.org/10.1038/s41586-020-2153-8.


The authors studied proteins from the teeth enamel -which degrade slower than DNA. These proteins came from a specimen of Homo antecessor, a hominin that lived in Spain (Atapuerca) 800 kya, and Dmanisi Homo erectus (1.77 My old). They compared them to those of Modern Humans, Neanderthals and Denisovans.


Their abstract highlights the following (quote):

  • "H. antecessor is a close sister lineage to subsequent Middle and Late Pleistocene hominins, including modern humans, Neanderthals and Denisovans."
  • "The modern-like face of H. antecessor—that is, similar to that of modern humans—may have a considerably deep ancestry in the genus Homo, and that the cranial morphology of Neanderthals represents a derived form."


The trees built by the authors show that both Dmanisi and Antecessor are part of our tree, but both lie on branches that do not lead to us. We branched from them. More evidence is needed to find these homins who cover the gap between us and them.


Note that the protein from the Dmanisi erectus was too damaged to provide useful information.


Keep safe, wash your hands, wear a mask and practice social distancing.


Written in an Argentina in isolation and lockdown.


Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2014 by Austin Whittall © 

Wednesday, September 4, 2019

Denisovan finger bone differs from Neanderthals and is similar to modern humans


Today Science Advances published a paper (Morphology of the Denisovan phalanx closer to modern humans than to Neanderthals, E. Andrew Bennett et al., Science Advances 04 Sep 2019: Vol. 5, no. 9, eaaw3950 DOI: 10.1126/sciadv.aaw3950), which looked into the morphology of a Denisovan finger bone and compared it to that of modern humans and neanderthals.


Surprisingly it is more similar to ours than to the Neanderthals' finger bones even though Denisovan and Neanderthal DNA is closer to each other than to us.


The authors state: "Our morphometric analysis shows that its dimensions and shape are within the variability of Homo sapiens and distinct from the Neanderthal fifth finger phalanges. Thus, unlike Denisovan molars, which display archaic characteristics not found in modern humans, the only morphologically informative Denisovan postcranial bone identified to date is suggested here to be plesiomorphic and shared between Denisovans and modern humans.".


Neanderthals had fingers with wider ends (or tufts), which were also longer -in proportion- than ours. The Denisovan finger bone falls within the dimensions and proportions of modern human fingers and is very different to that of their relatives, the Neanderthals.


The paper concludes:
" The nuclear genomes of Neanderthals and Denisovans are closer to each other than to modern humans, and it has been estimated that the population split time between Denisovans and Neanderthals is about 410 ka ago, whereas the population split time between these archaic humans and the ancestors of AMHs is about 580 ka ago ... Despite being evolutionary sister groups, the Denisova 3 DP5 does not exhibit any of the features seen in Neanderthals. Its morphology is indistinguishable from that of modern humans and located within modern human variation, which likely represents the plesiomorphic morphology of nonpollical DPs within the genus Homo as seen in both the Olduvai Hominin OH 7 and the Dmanisi hominins. This suggests that the Neanderthal-specific characters of the phalanx evolved after the divergence of Denisovans and Neanderthals. The only Neanderthal DP5 that falls in the middle of the modern human variation is from Moula-Guercy, one of the earliest members of the Neanderthal lineage from our sample dating to around 100 ka ago. This observation raises the possibility that the derived properties of the Neanderthal phalanx occurred rather late during the evolution of the Neanderthals. The similarity between the Denisovan phalanx and those of AMHs contrasts with the morphology of the molars of the Denisova individuals that are morphologically closer to more archaic humans from the Middle Pleistocene to the Late Pleistocene... This finding calls for caution when identifying potential Denisovan postcranial skeletal remains beyond Denisova, as their morphology might be ambiguous or more similar to modern humans than to Neanderthals."



Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2019 by Austin Whittall © 

Wednesday, August 1, 2018

45 KY old African teeth from Magubike with Neanderthal and H. erectus traits...


This paper Middle Stone Age human teeth from Magubike rockshelter, Iringa Region, Tanzania, by Pamela R. Willoughby, Tim Compton, Silvia M. Bello, Pastory M. Bushozi, Anne R. Skinner and Chris B. Stringer. Published: July 31, 2018https://doi.org/10.1371/journal.pone.0200530, discusses human teeth found in Africa:


They are significant because they come from Tanzania (the Magubike rockshelter) and are apparently fom Middle Stone Age (MSA) deposits dated and a "conservative estimate of their minimum age is 45,000 years" according to the paper.


As we all know, finding human remains in this part of Africa, especially those from the Middle Stone Age (which took place between 320,000 and 30,000 years ago) is a very rare event.


The authors try to find similarities between these ancient teeth and the San people (the San are always mentioned because they are assumed to be a "relict" of the original Homo sapiens that left Africa, the "oldest" extant humans, the "most diversified" members of our species.


And they say so, albeit cautiously, in this paper: "... a number of characteristics in the Magubike teeth suggest possible San affinities.".


But as we go into the details, it seems that these teeth are indeed quite unique, and, in my opinion, not at all like those of the San people:


Quoting the authors: (bold is mine)


"In summary, the Magubike teeth have the characteristics typical of African sub-Saharan Homo sapiens Holocene teeth, but aspects of the morphology of the upper canine and third premolar are atypical for the African mid/late Pleistocene sample. However, this may be at least partly due to its North African bias. Certain traits present ― e.g. the root shape of the lateral incisor and canine, and the presence of a cingulum pit on the lateral incisor ― are rare or absent in the comparative samples. Traits specific to Homo heidelbergensis / archaic Homo sapiens and Aterian teeth are not present. Despite their large size, there is some suggestion of San affinities, though this interpretation must be very tentative, being based on a single individual."


The interesting part is the similarity with Neanderthal and Homo erectus features: (again bold is mine)


"... The pronounced buccal vertical curvature of the canine root found at Magubike is seen in early teeth, Homo erectus and Neanderthal [22, 47], but not in samples of early modern Homo sapiens (Skhūl and Qafzeh) or European Upper Palaeolithic Homo sapiens[48].
In recent teeth, the buccal surface is usually straight or has a mild curvature [49]. The few canine roots that could be observed in the Kenyan early Holocene sample, and the two in the Gwisho sample, are straight, and in the mid/late Pleistocene sample only the Broken Hill canine has similar curvature to that of the Magubike canine.
"


In other words it is not found among early modern Homo sapiens, only in Neanderthals and H. erectus. The authors continue, finding some examples of curvature in recent African samples (7% of them - a low figure) which may have come from out of African migrants in more recent times...:


"However, four instances were found in the recent sub-Saharan East/South African sample (7%). Similarly, the incomplete root of the Magubike lateral incisor has pronounced buccal vertical curvature in contrast to the more evenly tapered form of recent teeth [50]. A lateral incisor of this form occurs at the Klasies River Main site [51] and in one of four in the Gwisho sample, but in just one out of seventy-five in the recent East/South African sample."


As we see in the preceden paragraph, there are yet more morphological traits that are not at all related to modern African samples.


And the authors admit the teeth's unusual uniqueness very clearly:


"The six Magubike teeth are differentiated from African archaic Homo sapiens / Homo heidelbergensis and Aterian teeth in terms of size and the lack of morphological traits that could be associated with these groups. They are also differentiated from the Kenyan early Holocene and Gwisho samples and more recent teeth in terms of the relative size of the incisors, the incisor crown heights, the relative crown heights of the two premolars, and the long premolar roots. However, the morphological evidence is contradictory, principally in relation to the canine having traits that are rare or absent in the African mid/late Pleistocene sample, though this may be partly due to the small size of this sample and its North African bias."


They attribute this to the small sample size and its "North African bias"


But why try to find them similar to San teeth? Well, orthodoxy requires it: oldest African remains of a Homo sapiens and "oldest" extant humans (SAN) "must" be related:


"Small bodied individuals recovered from East African LSA sites have often been described as having “Khoisanoid affinities”, implying an assumed connection with the small bodied people of South Africa, including the San [75]. There are also still people in northern Tanzania today whose languages are often related to Khoisan (the Hadzabe and Sandawe), implying some possible past connections with southern African peoples [78]."


But what if... the teeth resemble Homo erectus and Neanderthal teeth because these migrated INTO AFRICA? As we can see they don't resemble the African teeth of that time or those of early Modern Homo Sapiens...



Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2018 by Austin Whittall © 

Friday, May 11, 2018

Haplogroups of Humans and Neanderthals and Denisovans: mtDNA and Y chromosomes)


I have just read a paper that refutes my closing comments of this 2014 post: A shared Y chromosome lineage Neanderthals and Modern Humans but it does support the image I posted in it, pictured below:


Neanderthal and human Y chromosome tree
Hypothetical Y chromosome phylogenetic tree for humans and Neanderthal. Copyright © 2014 by Austin Whittall

I explained the image as follows: "the ancestral population of both humans and Neanderthals, split into two groups: one that would later evolve into modern humans, and another that would evolve into Neanderthals. Each would carry, in the beginning, the "original" archaic Y chromosome of the ancestral population, which, as each lineage accumulated mutations due to chance and positive selection would begin to grow in different directions, forming two distinct branches, which then in turn would continue branching as more mutations appeared."


And that is what the paper states (Reconstructing the genetic history of late Neanderthals by Mateja Hajdinjak et al., 652 NATURE VOL 555 29 march 2018, doi:10.1038/nature26151.) Figure 2 in the article is shown below, and it agrees with the Y chromosome tree that I proposed back in 2014:


Phylogenetic trees for mtDNA, autosomal DNA and Y-chromosome of humans, Neanderthals, Denisovans and Sima de los Huesos hominin. From Hajdinjak et al.

The Human haplogroups are on distinct branches, well away from those of the older hominins.


See this Sept. 2020 update.



Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2018 by Austin Whittall © 

Tuesday, May 27, 2014

A shared Y chromosome lineage Neanderthals and Modern Humans



I am following up on some (there were quite a few) of the subjects that appeared while writing my most recent posts on the human Y chromosome.


Among them, are my very serious doubts regarding the markers used in classifying Y-chromosome haplogroups, the ages of the different sub-clades or haplotypes within them, and the different dates for common ancestors based on the estimated mutation rates for the human Y chromosome. As expressed in my previous posts, the methods, assumptions and convoluted statistical calculations seem far fetched and very uncertain. The fact that some confidence intervals are too large in my opinion invalidate the logic behind them, but then, I am a mere engineer not a geneticist.


The Y chromosomes of the Neanderthal


It is in this context that I read an interesting paper (Musaddeque Ahmed and Ping Lian, 2013) [1], from which I quote the following regarding Neanderthal Y chromosomes ... (bold font is mine):


"...the Y-chromosome of Neanderthals or paternal inheritance has yet to be examined. Comparisons of the Y chromosome sequence of Neanderthals with currently established Y-haplogroups for modern humans should provide some insights into the admixture hypothesis.
With respect to the recent finding of admixture of Neanderthals with non-African populations, the Neanderthal Y chromosome should not match the Y haplogroups A or B, as these haplogroups are the oldest of the clades and almost restricted to Africans and their descendants. Since haplogroup E is found in Africa, the Middle East, Southern Europe, and Asia, the Neanderthal Y chromosome may match this haplogroup, but it should not match the haplogroups E1b1a*, E2b1, or B2a1a, as they are specifically treated as Bantu expansion markers, while Neanderthals interbred only with non-Africans.
" [1]


I was very surprised by this paragraph, as I expected something similar to what we see in mtDNA, where the ancestral population of both humans and Neanderthals, split into two groups: one that would later evolve into modern humans, and another that would evolve into Neanderthals. Each would carry, in the beginning, the "original" archaic Y chromosome of the ancestral population, which, as each lineage accumulated mutations due to chance and positive selection would begin to grow in different directions, forming two distinct branches, which then in turn would continue branching as more mutations appeared.


So, the oldest human Y-chromosome haplogroups "A" and "B" found exclusively in Africa, were born from the branch leading to modern humans (the "root" of mankind), while, on a separate branch, (Neanderthals), the Y chromosome haplogroups of Neanderthals appeared.


However, towards the end of this post we will see that this reasoning may not be correct.


Nevertheless, mainstream science considers it to be the correct interpretation. According to Krause et al. (2007), [2] since the oldest common ancestor with human Y chromosomes dates back to 90 kya, and as Neanderthals and humans split long before that date, they "expect[ed] Neandertal Y chromosomes to fall outside the variation of modern human Y chromosomes unless there was male gene flow from modern humans into Neandertals"; in other words: Neanderthals would have their own peculiar Y chromosome haplogroups unless H. sapiens men mated with Neanderthal women and passed on their Y chromosomes to their human-neanderthal mixed male sons. But then these would not be pure Neanderthals but admixed ones, with 50% human genome in them and their Neander mom's mtDNA.



The following image shows what I expressed above, two branches: red for Neanderthals and black for us, humans, both splitting from our common ancestor:


Neanderthal and human Y chromosome tree
Hypothetical Y chromosome phylogenetic tree for humans and Neanderthal. Copyright © 2014 by Austin Whittall

Actually, we have not yet found Neanderthal Y chromosomes among modern human genomes and this is indeed curious since we have admixed with them. It could be due to several reasons:


(a) They are present in such low frequencies that they have not yet been sampled. Imagine a 0.001% frequency, that is, only 1 in 100,000 men would carry it (35,000 in the whole world, a very small number indeed).
(b) They are very similar to modern haplogroups (as suggested by Musaddeque and Ping, 2013. [1]) and we see them but have not yet realized that they are Neanderthal.... (More on this below, because it seems to be a very interesting possibility).


While studying the Neanderthal genome, Krause et al., (2007) [2] found that two of their Sidrón Neanderthal specimens (Sidrón 1253 and Sidrón 1351c) were males. They then tested them at the five positions that mark the main nodes of Human branches (i.e. the splitting points of our Y chromosome haplogroups) in both Eurasia and Africa. They noticed that "all 15 Y chromosomal products for the five assayed positions show the ancestral allele" [2]. In other words, the ancestral or chimpanzee-like state was found. They did not find any specifically Neanderthal-like state. This is odd, considering that 7 million years separate chimps from Neanders, why would they both share the markers in their Y chromosomes and humans, a mere 300 ky away don't. It may be an error in their sequencing.


Admitting the paucity in their sampling and that these Y-chromosomes may appear in extremely low frequencies among modern human populations, the authors conclude:"These [Neanderthal] Y chromosome results must derive, then, either from Y chromosomes that fall outside the variation of modern humans or from the very rare African lineages not covered by the assay..." [2], in other words, the Neanderthal Y chromosomes may be similar to those of modern humans that were not screened for.


I must point however, that according to Figure S1, the "markers" chosen by Krause et al., screened only certain branches of the Y chromosome tree: (i) and (ii) the split that leads to all haplogroups downstream from the A clade. (B, C,.... R2). (iii), The one leading to B. (iv) The one leading to P, (and therefore Q), R1, R2. And (iv) the one leading to A2.


So the Neanderthal Y chromosomes could belong to Haplogroups A1 and A3, which were not screened for. Or, an option that is evident, but they did not consider it at all: Neanderthal Y chromosomes are identical to those of Modern Humans and cannot be told apart from them.


Actually, isn't it surprising that not one Neanderthal Y (or X with its mtDNA) chromosome survived until our days? We have a considerable amount of autosomal genetic content introgressed from our relatives, the Neanderthals, but their mithocondria and their sex determining chromosomes did not survive. Why?



An extremely old Y chromosome lineage


Mendez et al., (2013) [3] , discovered a Y chromosome haplogroup (named A00) which shares its most recent common ancestor with the rest of mankind 338 kya, of course (as usual!) the confidence interval is 237 to 581 kya. So this is a very old and wide time frame which goes back well beyond the oldest known fossils of anatomically modern human (AMH) beings.


This haplogroup was found in the genes of an African American and later identified in the chromosomes of Mbo individuals from Cameroon, at very low frequencies: 0.19% [CI = 0.11%–0.35%].


They would predate the oldest modern human fossils, which are only 195 ky old. So the Mbo lineage should have split from humanity at least 40 ky before our species even appeared.


The paper also looked at the rest of our Y chromosome lineages, working up the other branches of the tree, finding that the African A0 hg diverged from the other branches 202 kya (CI = 125 - 382 kya), which is much older than previous estimates of 142 kya.


This in turn moves the split between African and non-African branches (hg C to T) backwards in time, making them older: 63 kya vs. the previous 39 kya date.


Orthodoxy strikes back
Of course, such an ancient root for modern humans is inconsistent with mainstream genetic beliefs so a rebuttal appeared (Eran Elhaik et al., 2014)[4], pointing out that it: "contradicts all previous estimates in the literature and is over 100,000 years older than the earliest fossils of anatomically modern humans.".
E. Elhaik et al believe that Mendez et al.'s paper overestimated mutation rates resulting in an artificially older age. Their analyisis "indicates that the A00 lineage was derived from all the other lineages 208300 (95% CI= 163900 - 260200) years ago." [4] Which as can be seen, falls suitably close to the oldest dated AMH fossils.


New May 2018: Recent findings have pushed back both the earliest H. sapiens remains' datings in Africa and in Asia. This means that an older origin for AMH is indeed possible.


But let's get back to the very ancient A00 and the "unorthodox" point of view:


What are the implications of this finding? There are several possible scenarios:


1. Archaic admixture. These Mbo people inherited their A00 haplogroup from an achaic human population. These ancient African humans carried the A00 lineage in them, mated with AMH (within the last 195 ky) and passed on their Y chromosomes to their male offspring, their A00 passed from father to son in these AMH, which survived until now (Mbo's are their youngest descent). In the meantime, the archaic group became extinct.


Mendez et al. support this view: "Interestingly, the Mbo live less than 800 km away from a Nigerian site known as Iwo Eleru, where human skeletal remains with both archaic and modern features were found and dated to ~13 kya." [3]


2. Deeper time line. Maybe the depth of modern humans into the past is greater than the current (spotty) fossil record shows (roughly 200 kya).


The Confidence intervals given by Mendez et al., span from 237,000 to 581,000 years ago, this is well into the dark past of mankind, a time frame which encompasses many hominids in Eurasia and Africa: H. erectus (from 1.8 Mya until roughly 300 kya); Denisovans (until 30 kya), Homo heidelbergensis (600 to 400 kya), Neanderthals (600 to 25 kya) and H. rhodesiensis (300 to 125 kya).


Could this Y chromosome lineage belong to one of these hominids? Before answering let's just consider one additional piece of information.


Chuan-Chao Wang et al., [5] noticed that Y-chromosome STR haplotypes from different haplogroups converge; they looked for "possible haplotype similarities among haplogroups [and found] similar haplotypes between haplogroups B and I2, C1 and E1b1b1, C2 and E1b1a1, H1 and J, L and O3a2c1, O1a and N, O3a1c and O3a2b, and M1 and O3a2 ..." [5] .


In other words identical Short Tandem Repeat (STR) markers crop up among the different Y chromosome haplogroups indicating that the same mutations arise time and time again, unlike the markers of haplogroups which are much more sporadic and unique.


Making sense of this muddle


Above, I asked why didn't Neanderthal Y chromosomes survive among their descent (albeit admixed with modern humans)? Probably there were too few of them and too many of us, and their Y chromosomes got watered down, in successive admixtures, diluted until their frequencies are so low that they have not yet been detected.


Another option is that "Haldane's rule'' kicked in; the rule declares that if hybrids of one sex only are sterile, the afflicted sex is much more likely to be the male (XY) than the female (XX). Of course, why would hominds so close to each other bear sterile offspring? It is not like horses and donkeys, this is humans and Neanderthal, and we have their genes in us, so we did interbreed and the offspring survived (but Haldane's rule may mean that the girls survived but the boys were sterile).


A paper (Sankararaman et al., 2014) [6] supports the "Haldane's rule" notion: "...interbreeding of Neanderthals and modern humans introduced alleles onto the modern human genetic background that were not tolerated, which probably resulted in part from their contributing to male hybrid sterility".


The Neanderthal-deficient regions in modern humans are found in genes that "are specifically expressed in the testes, and in the female sex X chromosome. "This suggests that some Neanderthal-modern human hybrids had reduced fertility and in some cases were sterile. An unexpected finding is that regions with reduced Neanderthal ancestry are enriched in genes, implying selection to remove genetic material derived from Neanderthals. Genes that are more highly expressed in testes than in any other tissue are especially reduced in Neanderthal ancestry, and there is an approximately fivefold reduction of Neanderthal ancestry on the X chromosome." [6]


But, this does not mean a total extinction of their sex chromosomes; not all of their offspring were sterile after all, we still carry their genes mixed with ours, why shouldn't their Y chromosomes survive too?


In my opinion, we actuall carry their Y chromosomes in us (in the men of course), but long before we admixed with them in Eurasia some 60 kya. The mutation rates that are used to date our Y lineages are wrong, allow me to explain why:


We look at populations (say Amerindians) and jot down their haplogroup markers, and we assume that they mutated when they reached America and then, we guess the date they entered America (say 15 kya). With this we calibrate our clock. We again look at the humans closest to Africa and jot down their haplogroups markers, and once again guess the date these people's ancestors left Africa (say 70 kya), and again calibrate our clock. We take another look at the oldest fossils of AMH in Africa (195 kya) and jot down the most divergent African haplogroups' markers, we recalibrate our clock again. But, as you can see, there are many assumptions in all of this (the dates and, above all, the assumption that these haplogroups are specifically human and mutated recently < 200 ky!).


But, What if they are not specific to us, but archaic? What if we carry slowly mutating Y chromosomes. The mutations found in certain haplogroups are valid, but they reflect ancient migrations. Maybe even the Out Of Africa (OOA) migration of H. erectus or, within the time range given by Mendez et al., the Y chromosomes of H. heidelbergensis or Neanderthals?


This would explain why there are no Neanderthal specific branches to be found (the red ones in the image above). We all have the same tree our and their lineages coincide.


So what the date should we consider for the makers at the "non-African" CT groups (the OOA split)? Not the date modern humans left Africa. Instead it may be the date Neanderthals left Africa.


The split in Altai, with a Western route for our "R" hg and East for the "Q" hg may indicate divergence among the Neanderthals that lived there while AMH began to move out of Africa.


The archaic humans of China and even Lake Mungo people in Australia may be the branches of the South East Asian and Austronesian Y chromosome haplogroups, instead of modern humans that reached those regions much later.


The Q hg in America may not reflect a recent peoping of America at all, but an ancient one by Neanderthals.


The pan African E hg, may reflect the recent dispersal of AMH in the continent as well as in the Middle East, Southern Europe, and Asia after their OOA movement.


The dispersal of Q hg across the Arctic regions of America and Eurasia or the presence of the very old C hg in Asia and America may reflect the ancient migrations of primitive humans and not the recent (<20 kya) dispersal of modern humans.


See This post for an update. May 2018 and this Sept. 2020 update


Sources


[1] Musaddeque Ahmed and Ping Lian, (2013). Study of Modern Human Evolution via Comparative Analysis with the Neanderthal Genome. Genomics Inform. Dec 2013; 11(4): 230–238. Published online Dec 31, 2013. doi: 10.5808/GI.2013.11.4.230
[2] Johannes Krause, et al., (2007). The Derived FOXP2 Variant of Modern Humans Was Shared with Neandertals. Current Biology 17, 1–5, November 6, 2007 ª2007 Elsevier Ltd All rights reserved DOI 10.1016/j.cub.2007.10.008
[3] Fernando L. Mendez et. al., (2013). An African American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree. The American Journal of Human Genetics 92, 454–459, March 7, 2013. http://dx.doi.org/10.1016/j.ajhg.2013.02.002.
[4] Eran Elhaik, T. Tatarinova, A. Klyosov and D. Graur, (2014). The 'extremely ancient' chromosome that isn't: a forensic bioinformatic investigation of Albert Perry's X-degenerate portion of the Y chromosome. European Journal of Human Genetics (2014) 1-6. doi:19.1038/ejhg.2013.303
[5] Chuan-Chao Wang et al., (2013). Convergence of Y chromosome STR haplotypes from different SNP haplogroups compromises accuracy of haplogroup prediction. pre-print Arxiv server on 21 October 2013.
[6] Sriram Sankararaman et al., (2014). The genomic landscape of Neanderthal ancestry in present-day humans. Nature 507, 354–357 (20 March 2014) doi:10.1038/nature12961



Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2018 by Austin Whittall © 
Hits since Sept. 2009:
Copyright © 2009-2025 by Austin Victor Whittall.
Todos los derechos reservados por Austin Whittall para esta edición en idioma español y / o inglés. No se permite la reproducción parcial o total, el almacenamiento, el alquiler, la transmisión o la transformación de este libro, en cualquier forma o por cualquier medio, sea electrónico o mecánico, mediante fotocopias, digitalización u otros métodos, sin el permiso previo y escrito del autor, excepto por un periodista, quien puede tomar cortos pasajes para ser usados en un comentario sobre esta obra para ser publicado en una revista o periódico. Su infracción está penada por las leyes 11.723 y 25.446.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means - electronic, mechanical, photocopy, recording, or any other - except for brief quotations in printed reviews, without prior written permission from the author, except for the inclusion of brief quotations in a review.

Please read our Terms and Conditions and Privacy Policy before accessing this blog.

Terms & Conditions | Privacy Policy

Patagonian Monsters - https://patagoniamonsters.blogspot.com/