Archive for the ‘Anthropology’ Category

The one or the many

October 31, 2017

It is the classic dilemma of our age which shows up everywhere.

I nearly always tend towards prioritising the one primarily because without the one there cannot be the many, without the local you cannot get to global, without the national there is no international and without the excellence of the few you cannot get the good of the herd. I prefer the highest multiple possible to the lowest common factor. It colours my politics. I prefer the search for excellence rather than the common mediocrity of socialism. I prefer the the internationalism which comes as a consequence of strong nationalism to the bullying of the UN or the EU.

I side with “to each as he deserves” rather than to “each as he desires”. Freedoms flow bottom up from the individual to the group rather than privileges and sanctions flowing from the group down to the oppressed individual.


 

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Early hominins left Africa 6 million years ago

September 3, 2017

A foot print found in Crete is probably that of an early hominid and was made 5.7 million years ago.

The single Out-of-Africa theory sometime around 70,000 years ago is already obsolete. It was more likely to have been multiple hominin crossings out of Africa into both Europe and Asia. The expansion of homo sapiens sapiens is more likely to have been in  at least two waves out of Africarabia.  Homo erectus appeared around 2 million years ago while homo sapiens appeared about 1 million years ago.  Homo sapiens sapiens then split from homo sapiens neanderthalensis around 600,000 years ago. So the footprint found is that of a human ancestor after the split with chimpanzees (c. 8-9 million years ago), after the beginning of bipedalism but well before homo erectus appeared.

image from physorg

The paper is

Gerard D. Gierlińskia et al., Possible hominin footprints from the late Miocene (c. 5.7 Ma) of Crete? Proceedings of the Geologists’ Association, 2017 DOI: 10.1016/j.pgeola.2017.07.006

As the Uppsala University  press release puts it:

….. Ever since the discovery of fossils of Australopithecus in South and East Africa during the middle years of the 20th century, the origin of the human lineage has been thought to lie in Africa. More recent fossil discoveries in the same region, including the iconic 3.7 million year old Laetoli footprints from Tanzania which show human-like feet and upright locomotion, have cemented the idea that hominins (early members of the human lineage) not only originated in Africa but remained isolated there for several million years before dispersing to Europe and Asia. The discovery of approximately 5.7 million year old human-like footprints from Crete, published online this week by an international team of researchers, overthrows this simple picture and suggests a more complex reality. …….

The new footprints, from Trachilos in western Crete, have an unmistakably human-like form. This is especially true of the toes. The big toe is similar to our own in shape, size and position; it is also associated with a distinct ‘ball’ on the sole, which is never present in apes. The sole of the foot is proportionately shorter than in the Laetoli prints, but it has the same general form. In short, the shape of the Trachilos prints indicates unambiguously that they belong to an early hominin, somewhat more primitive than the Laetoli trackmaker. They were made on a sandy seashore, possibly a small river delta, whereas the Laetoli tracks were made in volcanic ash. …….

…… During the time when the Trachilos footprints were made, a period known as the late Miocene, the Sahara Desert did not exist; savannah-like environments extended from North Africa up around the eastern Mediterranean. Furthermore, Crete had not yet detached from the Greek mainland. It is thus not difficult to see how early hominins could have ranged across south-east Europe and well as Africa, and left their footprints on a Mediterranean shore that would one day form part of the island of Crete.

‘This discovery challenges the established narrative of early human evolution head-on and is likely to generate a lot of debate. Whether the human origins research community will accept fossil footprints as conclusive evidence of the presence of hominins in the Miocene of Crete remains to be seen,’ says Per Ahlberg.

Abstract

We describe late Miocene tetrapod footprints (tracks) from the Trachilos locality in western Crete (Greece), which show hominin-like characteristics. They occur in an emergent horizon within an otherwise marginal marine succession of Messinian age (latest Miocene), dated to approximately 5.7 Ma (million years), just prior to the Messinian Salinity Crisis. The tracks indicate that the trackmaker lacked claws, and was bipedal, plantigrade, pentadactyl and strongly entaxonic. The impression of the large and non-divergent first digit (hallux) has a narrow neck and bulbous asymmetrical distal pad. The lateral digit impressions become progressively smaller so that the digital region as a whole is strongly asymmetrical. A large, rounded ball impression is associated with the hallux. Morphometric analysis shows the footprints to have outlines that are distinct from modern non-hominin primates and resemble those of hominins. The interpretation of these footprints is potentially controversial. The print morphology suggests that the trackmaker was a basal member of the clade Hominini, but as Crete is some distance outside the known geographical range of pre-Pleistocene hominins we must also entertain the possibility that they represent a hitherto unknown late Miocene primate that convergently evolved human-like foot anatomy.


 

Fantasy or just bad science — “humans in North America 130,000 years ago”

April 27, 2017

Nothing wrong with fantasy of course. It just makes for bad science. The real problem here is that it is very bad science being encouraged by the journal Nature. The whole paper is based on analysing some crushed Mastodon bones which were found 25 years ago, a doubtful application of a dating technique and then the assertion that it was impossible for the bones to have been crushed by anything other than human activity. They made some experiments to crush bones and then they leap to their fantastic conclusion that the crushing was (was and not might have been) by stone tools (of which there are no traces) made by unknown humans (who also have left no other trace).

This is not just fantasy. It is borderline rubbish.

Controversial study claims humans reached Americas 100,000 years earlier than thought

The “science” is quite sophisticated —–

“Scientific” bone crushing

Even the staid BBC is driven to report:

Prof Michael R Waters, from Texas A&M University in College Station, described the new paper as “provocative”. He told BBC News the study “purports to provide evidence of human occupation of the Americas some 115,000 years before the earliest well established evidence”.

Prof Waters explained: “I have no issues with the geological information – although I would like to know more about the broader geological context – and the likely age of the locality. However, I am sceptical of the evidence presented that humans interacted with the mastodon at the Cerutti Mastodon site.  …… To demonstrate such early occupation of the Americas requires the presence of unequivocal stone artefacts. There are no unequivocal stone tools associated with the bones… this site is likely just an interesting paleontological locality.”

Prof Tom Dillehay, from Vanderbilt University in Nashville, Tennessee, told BBC News the claim was not plausible. Another authority on early American archaeology, Prof David Meltzer from Southern Methodist University in Dallas, Texas, said: “Nature is mischievous and can break bones and modify stones in a myriad of ways. ……. With evidence as inherently ambiguous as the broken bones and non-descript broken stones described in the paper, it is not enough to demonstrate they could have been broken/modified by humans; one has to demonstrate they could not have been broken by nature. ….. This is an equifinality problem: multiple processes can cause the same product.”


 

Why I am an optimist

March 16, 2017

From a talk I gave on 15th March

Sometimes, I’ve noticed, I irritate people around me who would rather be sad. I wondered why I was an optimist and always saw the glass half full. 

This example came to mind. 

It is perhaps not widely known that the world is facing a new crisis. It is an inescapable conclusion if two assumptions are correct. First, that intelligence – however it is defined – is hereditary. Second, that more intelligent people have fewer children. If intelligence is inherited and the intelligent have fewer children, it does not take an Einstein to realise that the world is getting dumber every day. 

We know that intelligence is at least partly hereditary. Furthermore, all over the world, the number of children the intelligent have has fallen sharply. It is simple arithmetic that generation after generation, the world must be dumbing down. Or rather, generation after generation, children of the world must have dumber parents. 

This reasoning has a few  flaws. Intelligence is not just hereditary. It also depends on nutrition, education and the environment the child grows up in. Knowledge is also not the same as intelligence, and measurement of intelligence cannot avoid including some influence of knowledge. It has been calculated that even if we do know that knowledge is increasing, and has increased continuously, human intelligence peaked when we were still hunter-gatherers about 15,000 years ago. So although human intelligence has probably reduced, it has done so very slowly and is partly compensated for by the increase of knowledge. What is clear, however, is that intelligence is not increasing at the rate it would if it were a survival factor for natural selection. 

In any case, if and when an intelligence problem becomes a crisis, we can always solve it with the right choice of  tax system. As you all and every politician knows, no problem exists that cannot be solved by an appropriate tax system. So, in the event of a crisis, my solution would be very simple. Income tax would be scrapped and replaced by a tax on intelligence. The tax would increase with intelligence, but those with higher intelligence than the average would have their tax rate reduced for each child, while those who were below average would have their rate increased with every child. 

The world would be a very boring place without problems to solve. 

Perhaps it is so that fiddling with the tax system is not the solution to every problem, but in my worldview, problems exist to be solved. Not a problem in every challenge, but a challenge in every problem.

And that is why I am an optimist.

source unknown


 

Deciphering the Harappan script – probably proto-Dravidian

October 21, 2015

The Indus-Saraswati Valley civilisation reached its peak around 1,900 BCE. It had been flourishing there for over a millennium from about 3300 BCE. But various proto-Harappan cultures had existed in those fertile plains for almost 4,000 years before that (from about 7,000BCE). At their peak they occupied the entire Indus -Saraswati Valley and stretched as far as the Indo-Gangetic plain. At its peak there were some 1,000 settlements and at least 5 “great” cities that we now know of; Mohenjo-Daro, Harappa, Ganweriwala, Rakhigarhi and Dholavira. None of these are truly coastal and it is not improbable that one or perhaps two “great” coastal cities are now submerged and waiting to be discovered. Only about 10% of the known sites have been investigated and the Indus Valley script – which I call Harappan for convenience – has yet to deciphered.

Where Unicorns roamed - graphic by Nature

Where Unicorns roamed – graphic by Nature

But by about 1,000 BCE the glories of the civilisation had disappeared; not swept away in one fell swoop by some marauding invaders or by some great pestilence or some cataclysmic natural catastrophe, but gradually as cities and settlements were abandoned and the population gradually thinned out and reduced to a shadow of its heyday. Coming out of the ice-age around 20,000 years ago, sea-levels were almost 100m lower than today. By 7,000 BCE (9,000 years ago) sea levels were already about 30m lower than at present and were rising fast at around 8-10 m/millennium. The settlements in the region were either on the coast or followed the course of the great rivers. It was a 300 – 500 year process of desertification which saw the Saraswati dry up and the creation of the Thar desert.

Saraswati and Thar Desert

Saraswati and Thar Desert

Where they all went is mainly conjecture but it is likely that they “followed the water”. Some of the sources of the Saraswati would have diverted to flow into the Ganges. That would have taken some people westwards, back along the coast towards the then fertile Persian Gulf, some eastwards across the Indo-Gangetic plain and some southwards along the coast of the Indian subcontinent. Quite possibly some reached the Bay of Bengal and others reached south India and the Indian Ocean. But they did not move into empty spaces. The Indian subcontinent had been continuously settled from the times of homo erectus but by the time of the Toba eruption 74,000 years ago homo erectus had already been replaced by homo sapiens. So when the Harappans moved in, modern humans were already there, but not in large numbers. The earlier settlers probably included the few survivors of a pre-Toba wave of expansion who were then absorbed by later settlers – probably many arrival instances – over some 50,000 years.

Where the Harappans probably went

Where the Harappans probably went

In my narrative it is the Harappans and their language which provided the nucleus for, and eventually became, the family of Dravidian languages. In fact it is probable that some of the roots of what became Hinduism came also with them. I would even suggest that the specialisation of functions (administrators, priests, traders, craftsmen and labour) that must have existed in the meticulously planned, water-resourceful, trading cities of the Indus-Saraswati Valley led to the foundation of guilds and a stratified society. That probably laid the foundations of the caste system which, in its perverted form, currently disgraces the subcontinent.

Andrew Robinson looks at the state of the decipherment of the Harappan script in Nature.

Nature 526, 499–501 (22 October 2015) doi:10.1038/526499a.

Cracking the Indus script

Indus unicorn on a roughly 4,000-year-old sealstone, found at the Mohenjo-daro site. photo – Robert Harding/Corbis

The Indus civilization flourished for half a millennium from about 2600 bc to 1900 bc. Then it mysteriously declined and vanished from view. It remained invisible for almost 4,000 years until its ruins were discovered by accident in the 1920s by British and Indian archaeologists. Following almost a century of excavation, it is today regarded as a civilization worthy of comparison with those of ancient Egypt and Mesopotamia, as the beginning of Indian civilization and possibly as the origin of Hinduism. 

More than a thousand Indus settlements covered at least 800,000 square kilometres of what is now Pakistan and northwestern India. It was the most extensive urban culture of its period, with a population of perhaps 1 million and a vigorous maritime export trade to the Gulf and cities such as Ur in Mesopotamia, where objects inscribed with Indus signs have been discovered. Astonishingly, the culture has left no archaeological evidence of armies or warfare.

Most Indus settlements were villages; some were towns, and at least five were substantial cities …  boasted street planning and house drainage worthy of the twentieth century ad. They hosted the world’s first known toilets, along with complex stone weights, elaborately drilled gemstone necklaces and exquisitely carved seal stones featuring one of the world’s stubbornly undeciphered scripts. …

The Indus script is made up of partially pictographic signs and human and animal motifs including a puzzling ‘unicorn’. ….. 

Whatever their differences, all Indus researchers agree that there is no consensus on the meaning of the script. There are three main problems. First, no firm information is available about its underlying language. Was this an ancestor of Sanskrit or Dravidian, or of some other Indian language family, such as Munda, or was it a language that has disappeared? Linear B was deciphered because the tablets turned out to be in an archaic form of Greek; Mayan glyphs because Mayan languages are still spoken. Second, no names of Indus rulers or personages are known from myths or historical records: no equivalents of Rameses or Ptolemy, who were known to hieroglyphic decipherers from records of ancient Egypt available in Greek. ……

……. Nevertheless, almost every researcher accepts that the script contains too many signs to be either an alphabet or a syllabary (in which signs represent syllables), like Linear B. It is probably a logo-syllabic script — such as Sumerian cuneiform or Mayan glyphs — that is, a mixture of hundreds of logographic signs representing words and concepts, such as &, £ and %, and a much smaller subset representing syllables.

As for the language, the balance of evidence favours a proto-Dravidian language, not Sanskrit. Many scholars have proposed plausible Dravidian meanings for a few groups of characters based on Old Tamil, although none of these ‘translations’ has gained universal acceptance. ……… A minority of researchers query whether the Indus script was capable of expressing a spoken language, mainly because of the brevity of inscriptions. ……. This theory seems unlikely, for various reasons. Notably, sequential ordering and an agreed direction of writing are universal features of writing systems. Such rules are not crucial in symbolic systems. Moreover, the Indus civilization must have been well aware through its trade links of how cuneiform functioned as a full writing system. ……….

What the Harappans wrote and spoke was not Dravidian itself, but it was very likely a proto-Dravidian language, which, with many other influences from what already existed in the South Indian regions they moved into, became the family of Dravidian languages existing today. And it could explain why a Dravidian language can be found today in what is Afghanistan.

Dravidian language subgroups - map Wikipedia

Dravidian language subgroups – map Wikipedia

 

Ancient Chinese teeth confirm many and older Out of Africa events

October 15, 2015

Over at 6,000 generations I post about the new paper about the 47 human teeth found in Fuyan Cave, Daoxian, China which are between 80,000 and 120,000 years old.

The 47 human teeth found in Fuyan Cave, Daoxian, China. photo S. XING AND X-J. WU via DiscoveryNews

There were clearly many Out of Africa or Africarabia events starting from 130,000 years ago both before and after the Toba explosion.

80,000-120,000 year old modern humans in S China confirm many and older Out of Africa events

The single Out of Africa event for modern humans is clearly far too simplistic. It is also clear that there were many back to Africa movements as well. Humans expanded sometimes because their old habitats were no longer viable. But, it seems, humans also explored and expanded into new territories from regions of plenty and where they maintained some contact with where they had come from. Probably, just because they could.

Genetic mutations among the Inuit demonstrate the reality of “race”

September 23, 2015

It is politically correct to claim that “race” is just an artificial social construct. But of course “race” is real. It is about ancestry and about genetic differences that are quite real. It is about the groupings of peoples exhibiting the same genetic variations. Genetic studies are increasingly confirming the genetic differences that are distinguishable among the many ethnic groups of humans. Genetic groupings exist and are real but they are dynamic, not static. The genetic groupings (colloquially “race”) were different 1,000 generations ago and they will be different again in the future.

A new study shows that

“the Inuit and their Siberian ancestors have special mutations in genes involved in fat metabolism. The mutations help them partly counteract the effects of a diet high in marine mammal fat, mostly from seals and whales that eat fish with high levels of omega-3 polyunsaturated fatty acids.

Those genetic mutations, found in nearly 100 percent of the Inuit, are found in a mere 2 percent of Europeans and 15 percent of Han Chinese, which means that these groups would synthesize omega-3 polyunsaturated fatty acids differently from the Inuit. ….

The mutations seem to be at least 20,000 years old, and may have helped many groups of humans adapt to high-meat, high-fat, hunter-gatherer diets from large land and marine mammals high in certain types of omega-3 and omega-6 fatty acids, ……. They may have arisen among the original Siberians, who have lived in the Arctic for more than 20,000 years and arrived in Greenland when Inuit settled there about 1,000 years ago.”

Matteo Fumagalli et al,  Greenlandic Inuit show genetic signatures of diet and climate adaptation. Science, 18 September 2015 DOI:10.1126/science.aab2319

NewsBerkeley: ……. “The original focus on fish oil and omega-3s came from studies of Inuit. On their traditional diet, rich in fat from marine mammals, Inuit seemed quite healthy with a low incidence of cardiovascular disease, so fish oil must be protective,” said project leader Rasmus Nielsen, a UC Berkeley professor of integrative biology. “We’ve now found that they have unique genetic adaptations to this diet, so you cannot extrapolate from them to other populations. A diet that is healthy for the Inuit may not necessarily be good for the rest of us.”

These genetic mutations in the Inuit have more widespread effects. They lower “bad” LDL cholesterol and fasting insulin levels, presumably protecting against cardiovascular disease and diabetes. They also have a significant effect on height, because growth is in part regulated by a person’s fatty acid profile. The researchers found that the mutations causing shorter height in the Inuit are also associated with shorter height in Europeans.

Seals and walruses were part of the traditional diet of the Inuit, as seen in this illustration of a native village on Canada’s Baffin Island, from the book Arctic Researches and Life Among the Esquimaux (1865) by Charles Francis Hall.

“The mutations we found in the Inuit have profound physiological effects, changing the whole profile of fatty acids in the body, plus it reduces their height by 2 centimeters: nearly an inch,” said Ida Moltke, a University of Copenhagen associate professor of bioinformatics who is joint first author on the study. “Height is controlled by many genes, but this mutation has one of the strongest effects on height ever found by geneticists.”

Nielsen noted that this is some of the clearest evidence to date that human populations are actually adapted to particular diets; that is, they differ in the way they physiologically respond to diets. Just as genome sequencing can lead to personalized medicine tailored to an individual’s specific set of genes, so too may a person’s genome dictate a personalized diet. 

Nielsen and his colleagues at UC Berkeley and in Greenland and Denmark came to their conclusions after analyzing the genomes of 191 Greenlanders with a low admixture of European genes (less than 5 percent) and comparing them to the genomes of 60 Europeans and 44 Han Chinese. They looked for mutations occurring in a large percentage of Inuit individuals but in few or no other groups, which indicates that the mutation spread throughout the Inuit because it was somehow useful to their survival while not essential in other groups.

One cluster of mutations — in genes that code for enzymes that desaturate carbon-carbon bonds in fatty acids — stood out strongly, said Anders Albrechtsen, an associate professor of bioinformatics at the University of Copenhagen and a joint project leader. Fatty acids are the fat in our diet, and occur in saturated, polyunsaturated and unsaturated forms, depending on whether the molecules’ carbon atoms are linked together with no, some or all double bonds. Saturated fats are considered bad because they raise levels of cholesterol in the blood and lower the “good” high-density lipoproteins (HDL), all of which leads to plaque formation and clogged arteries. Diets rich in polyunsaturated and unsaturated fats are linked to lower heart disease. Desaturase enzymes convert dietary fatty acids into fatty acids stored and metabolized by the body.

The mutations common in the Inuit, once known as Eskimos, decrease the production of both omega-3 and omega-6 polyunsaturated fatty acids, presumably to account for the high amount of these fatty acids coming from the diet. Changing production of one fatty acid affects all fatty acids, however, since they regulate one another in a complex way, Albrechtsen said.

Thus, while it’s not clear which specific gene or genes within the cluster is responsible for the alteration in fatty acid metabolism, he said that “when you change the genes that are involved in fatty acid synthesis, you change the whole conversation among fatty acids, and that has a lot of downstream effects.” …… The researchers discovered another common mutation in a gene that is involved in the differentiation of brown, subcutaneous fat cells and brite fat cells, the latter of which generate heat. This may also have helped the Inuit adapt to a cold environment.

Race is real but it is dynamic. The genetically distinguishable race of Inuits goes back about 1,000+ generations. And some other genetic groupings of humans will be observable 1,000 generations on. But those groupings (races) will still be there. As I observed some time ago

We have no difficulty in accepting that different populations (effectively different races in colloquial usage) have differences of physical characteristics due to their genetic ancestry. There is no great outrage now that recent studies point to some genetic differences that Tibetans have which may give them an advantage in absorbing oxygen at high altitudes. Similarly there are no screams when other genetic studies suggest that East Africans (Kenyans and Ethiopians in the main) have some genes – or combination of genes – which give them better endurance and therefore – given good nourishment – lead to better performance as long distance runners. West Africans, or those of West African descent, it seems may have some genetic advantages which make them the fastest sprinters over short distances. African genes also seem to give a lower fat content in body mass – which is genetic – and may be one explanation why their performance as swimmers is less than exceptional. That Indians are more prone to Type 2 diabetes than other “races” is not indignantly opposed but just taken for the observation it is. Indian-Americans (3 generations) are already exhibiting lower rates than their Indian ancestry would indicate. Japanese have very low rates of heart disease but already (in less than 6 generations) Japanese-Hawaiians have heart disease rates that are 2 -3 times higher.

It is illogical to assume that these genetic variations between different geographic populations ( colloquially “races”) have only manifested themselves as physical variations. It is highly probable and probably inevitable that these genetic developments will also have affected the brain, its functioning and behaviour. And intelligence.

If it is acceptable – and not racist – to observe that there are genetic differences in physical characteristics between the “races” of today, then it is just as acceptable and no more racist to observe that there are genetic differences of intelligence between the “races” of today.

The taboo against even discussing genetic groupings (race) and physical and mental characteristics (intelligence) and behaviour is illogical.

A jawbone with a Neanderthal for a great-great-grandmother

May 30, 2015

That humans today have genes from Neanderthals, Denisovans and some other ancient cousin species seems to be quite clear from the genetic evidence (though I am always quite amazed at the wondrous ability to extract DNA from ancient bones). In fact, it seems that the mainstream of AMH had various breeding encounters with these other species at many different times and (presumably) at many geographic locations. These encounters could not have been rare isolated events suggesting that there was more than a little promiscuity in the pleistocene.

Gene flow in the late pleistocene (Kay Prüfer et al)

It has been thought that most of the Neanderthal/AMH interactions must have taken place in the Middle East or central Asia, but new work indicates that these interactions took place in Europe as well. DNA analysis of a jawbone from a Romanian cave from about 40,000 years ago had a Neanderthal for a great-great- grandparent.

I take this grandparent to be a Neanderthal grandmother who was abducted by some marauding group of promiscuous humans only because the ensuing child survived to give rise to us and it is the human environment which has continued. The picture I have is that our Neanderthal genes today are due mostly to the Neanderthal females who were “impressed” into service by an aggressive and expanding human population. There may well have been Neanderthal male – human female offspring but they would more likely have been brought up in a Neanderthal environment, which – along with them -has not survived.

Ewen Callaway reports in Nature News:

Early European may have had Neanderthal great-great-grandparent

One of Europe’s earliest known humans had a close Neanderthal ancestor: perhaps as close as a great-great-grandparent.

The finding, announced on 8 May at the Biology of Genomes meeting in Cold Spring Harbor, New York, questions the idea that humans and Neanderthals interbred only in the Middle East, more than 50,000 years ago.

Qiaomei Fu, a palaeogenomicist at Harvard Medical School in Boston, Massachusetts, told the meeting how she and her colleagues had sequenced DNA from a 40,000-year-old jawbone that represents some of the earliest modern-human remains in Europe. They estimate that 5–11% of the bone’s genome is Neanderthal, including large chunks of several chromosomes. (The genetic analysis also shows that the individual was a man). By analysing how lengths of DNA inherited from any one ancestor shorten with each generation, the team estimated that the man had a Neanderthal ancestor in the previous 4–6 generations. (The researchers declined to comment on the work because it has not yet been published in a journal).

……. All humans who trace their ancestry beyond sub-Saharan Africa carry a sliver of Neanderthal DNA — around 1–4% of their genomes. Researchers have long thought it most likely that early humans exiting Africa interbred with resident Neanderthals somewhere in the Middle East around 50,000—60,000 years ago, before travelling on to Asia, Europe and the rest of the world.

That possibility has gained support in the past year. Last year, a team that included Fu used the genome of a 45,000-year-old human from Siberia to date his Neanderthal ancestors to between 50,000 and 60,000 years ago (when modern humans were probably starting to leave Africa)2. Another reported finding the 55,000-year-old partial skull of a human in an Israeli cave not far from sites at which Neanderthals lived around the same time3.

But radiocarbon dating of remains from sites across the continent suggests that humans and Neanderthals lived together in Europe for up to 5,000 years in some areas — plenty of time for them to have met and interbred there, too.

But the AMH / Neanderthal co-existence was not a short-lived thing.

Encounters between AMH and Neanderthals probably took place at different times in different places to leave the genetic signal of some 3% Neanderthal genes in non-African AMH. Early encounters would have taken place in central Asia (perhaps 50,000 years ago) with later encounters in Europe (c. 30,000 years ago). Now new methods of radiocarbon dating at archaeological sites is providing evidence which indicates that Neanderthals and AMH overlapped for many hundreds of generations.

 

 

The Anthropocene began 400,000 years ago when fire was “controlled”

March 13, 2015

A new paper tries to address when the “age of man” – the Anthropocene – bagan. The authors argue for 1610 when “an unusual drop in atmospheric carbon dioxide and the irreversible exchange of species between the New and Old Worlds” began.

I find this a rather arrogant Eurocentric fantasy which is less than convincing. Animal species – and humans – reached the Americas and Australia and Europe long before that.  The Norsemen took rats over to the Americas 500 years before that. Dog species from India crossed to Australia somehow 10,000 years ago. Darwin did not take wild-life to the Galapagos – they were already there. That the ancient civilizations of Egypt and China and the Mohenjo-Daro Valley were not part of the “Age of Man” seems to me to be just arrogance. That the Greeks or the Romans came before the “Age of Man” borders on stupidity. The Age of Man must begin when the dominance of the species Homo becomes established and sustainable.  While there is no other species which uses tools  as widely as Humans some other species do use tools. But there is no other species at all which can start a fire let alone control it.

Simon L. Lewis, Mark A. Maslin. Defining the Anthropocene. Nature, 2015; 519 (7542): 171 DOI: 10.1038/nature14258

Summary: Time is divided by geologists according to marked shifts in Earth’s state. Recent global environmental changes suggest that Earth may have entered a new human-dominated geological epoch, the Anthropocene. Here we review the historical genesis of the idea and assess anthropogenic signatures in the geological record against the formal requirements for the recognition of a new epoch. The evidence suggests that of the various proposed dates two do appear to conform to the criteria to mark the beginning of the Anthropocene: 1610 and 1964. The formal establishment of an Anthropocene Epoch would mark a fundamental change in the relationship between humans and the Earth system.

The advent and control of fire led – eventually but inevitably –  to the Stone Age transforming into the Bronze Age and the Iron Age. And in due course it has given the Machine Age, the Electrical Age, the Plastics Age and the current Semiconductors Age. All these “Ages” are surely part of the Anthropocene. There is a case to be made for the advent of stone tools defining Man but I think there is a much stronger case to be made for the advent and control of fire being what defines and distinguishes “Man” from all other animals.

Once fire was harnessed, the dominance of Homo Sapiens not just over other species but also over the environment became inevitable. Fire saw humans through the Ice Ages. The Stone Age plus fire gave the Bronze Age. The Bronze Age + fire led to the Iron Age. It was fire in its various avatars (hearths to ovens to smelters, or energy to steam to electricity) which helped transform one Age to the next.

The one single capability which initiated the divergence of humans from all other animals and which has resulted in the inevitable development and domination of modern humans is the control of fire. And that was around 400,000 years ago. The Age of Man began when Homo Erectus learned to produce fire at will and to contain fire in a hearth. I would even speculate that without fire Homo Erectus would not have survived to evolve into Homo Sapiens. Without fire Homo Sapiens would not have thrived through the ice ages or left the tropics to colonise more northern climes.

The Age of Man started long before 1610. Perhaps 1610 is a date of great significance – but that was not the start of the Age of Man. The Anthropocene started with fire 400,000 years ago.

 

In Norway, more sun correlates to reduced inherited fertlity and greater infant mortality

January 10, 2015

There is a new intriguing paper from The Norwegian University of Science and Technology (NTNU):

G. R. Skjaervo, F. Fossoy, E. Roskaft. Solar activity at birth predicted infant survival and women’s fertility in historical Norway. Proceedings of the Royal Society B: Biological Sciences, 2015; 282 (1801): 20142032 DOI:10.1098/rspb.2014.2032

Researchers studied Norwegian church records of 9,000 people from the period 1750-1900 and looked at life history variables and compared them with environmental factors including solar activity.

NTNU Press Release: Skjærvø and her colleagues found that children born in the years with lots of solar activity had a higher probability of dying compared to children who were born in the years with less solar activity.

On average, the lifespan of children born in years that had a great deal of solar activity was 5.2 years shorter than other children. The largest difference was in the probability of dying during the first two years of life.

Children who were born in years with lots of sunshine and who survived were also more likely to have fewer children, who in turn gave birth to fewer children than others. This finding shows that increased UV radiation during years of high solar activity had an effect across generations.

Skjærvø used information on the number of sunspots as an indication of the amount of UV radiation in a given year. The number of sunspots reaches a maximum every 11 years on average, which results in more UV radiation on Earth during years with high sunspot and solar activity.

UV radiation can have positive effects on human vitamin D levels, but it can also result in a reduction of vitamin B9 (folate). It is known that low folate levels during pregnancy are linked to higher child mortality.

The NTNU study showed that families from the lowest socio-economic groups were most affected by UV radiation. This is probably related to the time period Skjærvø studied, which was a time of clear class distinctions in Norway, especially in rural areas. Women who worked in the fields were more exposed to the sun than other women. In many cases they also had a poorer diet.

If the primary mechanism for such connections is through UV radiation, then it presumably does not have the same impact on those with darker skin. But I suppose that the records from tropical or equatorial regions are not as comprehensive or reliable as old Norwegian church records.


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