Archive for the ‘Genetics’ Category

Sherpas are genetically more efficient at using Oxygen

May 23, 2017

A new paper today confirms that Sherpas are genetically more efficient at using Oxygen. It is another example of an ethnic group where defining characteristics of the group are genetically inherited.

Horscroft, J et al. Metabolic basis to Sherpa altitude adaptation. PNAS; 22 May 2017; DOI: 10.1073/pnas.1700527114

EurekAlertSherpas have evolved to become superhuman mountain climbers, extremely efficient at producing the energy to power their bodies even when oxygen is scarce, suggests new research published today in the Proceedings of the National Academy of Sciences (PNAS). …..

When oxygen is scarce, the body is forced to work harder to ensure that the brain and muscles receive enough of this essential nutrient. One of the most commonly observed ways the body has of compensating for a lack of oxygen is to produce more red blood cells, which are responsible for carrying blood around the body to our organs. This makes the blood thicker, however, so it flows more slowly and is more likely to clog up blood vessels.

Mountain climbers are often exposed to low levels of oxygen, particularly at high altitudes. This is why they often have to take time during long ascents to acclimatise to their surroundings, giving the body enough time to adapt itself and prevent altitude sickness. In addition, they may take oxygen supplies to supplement the thin air.

Scientists have known for some time that people have different responses to high altitudes. While most climbers require additional oxygen to scale Mount Everest, whose peak is 8,848m above sea level, a handful of climbers have managed to do so without. Most notably, Sherpas, an ethnic group from the mountain regions of Nepal, are able to live at high altitude with no apparent consequences to their health – as a result, many act as guides to support expeditions in the Himalayas, and two Sherpas are known to have reached the summit of Everest an incredible 21 times.

Previous studies have suggested differences between Sherpas and people living in non-high altitude areas, known collectively as ‘lowlanders’, including fewer red blood cells in Sherpas at altitude, but higher levels of nitric oxide, a chemical that opens up blood vessels and keeps blood flowing.

Evidence suggests that the first humans were present on the Tibetan Plateau around 30,000 years ago, with the first permanent settlers appearing between 6,000-9,000 years ago. This raises the possibility that they have evolved to adapt to the extreme environment. This is supported by recent DNA studies, which have found clear genetic differences between Sherpa and Tibetan populations on the one hand and lowlanders on the other. Some of these differences were in their mitochondrial DNA – the genetic code that programmes mitochondria, the body’s ‘batteries’ that generate our energy.

To understand the biological differences between the Sherpas and lowlanders, a team of researchers led by scientists at the University of Cambridge followed two groups as they made a gradual ascent up to Everest Base Camp at an elevation of 5,300m.

The study was part of Xtreme Everest, a project that aims to improve outcomes for people who become critically ill by understanding how our bodies respond to the extreme altitude on the world’s highest mountain. This year marks 10 years since the group’s first expedition to Everest.

The lowlanders group comprised 10 investigators selected to operate the Everest Base Camp laboratory, where the mitochondrial studies were carried out by James Horscroft and Aleks Kotwica, two PhD students at the University of Cambridge. They took samples, including blood and muscle biopsies, in London to give a baseline measurement, then again when they first arrived at Base Camp and a third time after two months at Base Camp. These samples were compared with those taken from 15 Sherpas, all of whom were living in relatively low-lying areas, rather than being the ‘elite’ high altitude climbers. The Sherpas’ baseline measurements were taken at Kathmandu, Nepal.

The researchers found that even at baseline, the Sherpas’ mitochondria were more efficient at using oxygen to produce ATP, the energy that powers our bodies.

As predicted from genetic differences, they also found lower levels of fat oxidation in the Sherpas. Muscles have two ways to get energy – from sugars, such as glucose, or from burning fat (fat oxidation). The majority of the time we get our energy from the latter source; however, this is inefficient, so at times of physical stress, such as when exercising, we take our energy from sugars. The low levels of fat oxidation again suggest that the Sherpas are more efficient at generating energy.

The measurements taken at altitude rarely changed from the baseline measurement in the Sherpas, suggesting that they were born with such differences. However, for lowlanders, measurements tended to change after time spent at altitude, suggesting that their bodies were acclimatising and beginning to mimic the Sherpas’.

One of the key differences, however, was in phosphocreatine levels. Phosphocreatine is an energy reserve that acts as a buffer to help muscles contract when no ATP is present. In lowlanders, after two months at high altitude, phosphocreatine levels crash, whereas in Sherpas levels actually increase.

In addition, the team found that while levels of free radicals increase rapidly at high altitude, at least initially, levels in Sherpas are very low. Free radicals are molecules created by a lack of oxygen that can be potentially damaging to cells and tissue.

“Sherpas have spent thousands of years living at high altitudes, so it should be unsurprising that they have adapted to become more efficient at using oxygen and generating energy,” says Dr Andrew Murray from the University of Cambridge, the study’s senior author. “When those of us from lower-lying countries spend time at high altitude, our bodies adapt to some extent to become more ‘Sherpa-like’, but we are no match for their efficiency.” ……

Race is not a social construct as the politically correct would have me believe. Race is real and is a consequence of ancestry. Racial classification is fluid and changes but only over generational time. Sherpa genes help high-altitude living. There are West African genes which help sprinters, East African genes which are beneficial for long-distance runners, Scandinavian genes which predispose to diabetes 1 and Indian genes which predispose to diabetes 2.

And there are genes which predispose to high performance in IQ testing.


Inheritance rules

March 8, 2017

Genes surely define the behavioural envelope within which an individual can operate. This envelope, though, is quite wide. Nevertheless, one would think that after some 10,000 generations of evolution as anatomically modern humans, living in societies where cooperation is primal, that all those beneficial behavioural traits which had a genetic component, would have by now been selected. But psychopaths are not extinct, anti-social behaviour is very common and compassion is not a survival trait to be selected for. Barbarism has not been deselected by evolution. It could be that the same genes which give religious fanaticism also give rise to artistic creativity.

One would also have expected that the intelligence we credit humans with, and see as a key differentiating factor from other creatures, would also have been selected as a trait. Of course intelligence is not so easily defined and it certainly is not just the result of an IQ test. There are suggestions, from brain size measurements, that intelligence, as given by brain size, peaked when we were still hunter gatherers, possibly because that was when individuals needed to be very autonomous and – by inference – quite selfish to survive.  IQ tests today are not a good predictor of the success of an individual in society, probably because the test does not capture those aspects of intelligence that have to do with leadership, team work or entrepreneurial ability.

There was a time when light and dark were outside human control. So far we have left evolution to take its slow, natural, wasteful, trial and error course. But the speed of natural selection is now completely out of sync with the speed of change. The few attempts to guide evolution have been discredited by the manner in which they have been applied. They have been based on the principles we have used to breed livestock and dogs by terminating unwanted characteristics and only allowing individuals with desired characteristics to have progeny. The Nazi experiments with eugenics and even Margaret Sanger’s objectives of controlling the black population in the US (by making abortions freely available) were horrible (still are in some instances), in their manner of execution. But the idea of guiding our own evolution is still sound and an idea whose time has still to come. We are already tinkering with eugenics – though in a very amateurish way – when foetuses are aborted, or IVF is used, or when sperm banks are drawn upon, or fertility drugs or surrogacy are employed. Now, we have a sort of eugenics by default. When foetuses are screened genetically as a matter of course, and when genetic manipulation and correction becomes possible then eugenics will have properly arrived.


The Patriarch

September 8, 2016

Circa 1915




The Patriarch (probably born between 1860-1870), with

  • his two sons seated to his right,
  • their wives standing behind them
  • his two daughters standing behind him and
  • his four grandchildren



Natural selection is obsolete and the compassionate society needs non-coercive eugenics

March 20, 2016

Natural selection is about being “good enough” and never about excellence. It has been sufficient to the purpose to cope with the slow change of prevailing environment. It has been effective but remarkably inefficient. But now that homo sapiens has developed to the point of influencing – even if not yet controlling – the prevailing environment, the trial and error process of “natural selection” can no longer cope with the pace of change. Compassionate societies take care of their physically unfit and natural selection is effectively bypassed.

Natural selection is about “good enough”, but artificial selection could be about excellence

Natural selection has no direction. In fact it is unintended selection. It just allows for the survival and the reproduction of the “just good enough” individuals (not of the best individuals). “Evolution” is then just the resulting changes in species, where some individuals have had the genetic variation (errors or abnormalities) to be able to survive in a changed environment (habitat and/or competing species). Paradoxically, species which display a wide genetic variation in individuals (large errors), have a greater chance of surviving change. Of course, many abnormal individuals fail to survive, which is the price paid for the survival of the species. In that sense, “natural selection” sacrifices individuals for the sake of the species. The unplanned, unintended “selection” occurs primarily by the deselection of the unfit individuals. You could say it was unethical, since the end (species survival), justifies the means (deselection of unfit individuals). There is no compassion for deselected individuals in natural selection.

Excellence of a particular attribute is never selected for. Survivors are those just good enough, to live long enough, to reproduce. Evolution by this “natural selection” clearly works, but it is not intentional, is not very efficient and can only cope with slow, small changes to the environment. Rapid or large changes cannot be matched by the available genetic variation. When the genetic variation (errors) among individuals does not throw up some which can survive some external change, species go extinct. It is the selection not by a pro-active choice but by whatever is left surviving after a multitude of trials of the errors.

We are getting to the point where we are beginning to be able to discern the genetic components which, partially or wholly, determine health, disease, intelligence and behaviour of the individual. We no longer allow the sick and unintelligent to be deselected. The “compassionate society” has effectively short-circuited the natural selection process which depended on the physically “unfit” dying off. However we take no similar actions about those who are mentally or behaviourally unfit. We have started changing the environment and we have cancelled the death of the physically unfit. But we still allow the mentally or behaviourally unfit to survive and reproduce.

It is time then to also take charge of genetic selection.

We see nothing wrong in genetic intervention in preventing debilitating disease. We even allow capital punishment (abortion) where the genetic fault in a foetus is considered very large. We practice artificial selection – of a sort – with IVF and surrogate motherhood. “Genetic engineering”, and “artificial selection” are nothing but eugenics where no coercion is involved. The Nazi search for “racial purity” involved massive coercion and tried to achieve the goal of a particular physical appearance and external attributes which defined their “master race”.

But without coercion, eugenics is unexceptionable as a method to seek genetic excellence.

Eugenics:The Problem Is Coercion

Razib Khan in The Unz Review

…… the issue with nics is simple: the problem is coercion, and the rest is commentary. I understand that the public is wary and skeptical of CRISPR technology and preimplanation genetic diagnosis. The problem is that the public is also suspicious of food which has DNA in it. Genes are not magic, but that is hard to convince the person on the street. Whereof one does not know, thereof one must be suspicious.

I believe for there to be a clear discussion, one needs to take coercion off the table, and abolish its specter by stating that it just isn’t an option. Then we can have a real dialogue that gets beyond the superficiality induced by the shadow of genocide. For example, consider sentences such as the following from the op-ed above “editing genes for frivolous purposes such as increasing intelligence.” There are many technical reasons that it may not be possible to increase intelligence in the near future through genetic engineering. But would increasing one’s intelligence be frivolous? I don’t think so. Whether you agree with this project or not, it is a serious matter, and gets to the heart of what we value as human beings (or at least some of us). But the specter of genocide casts a pall on exploring these nuanced questions, and that is because of the past record of coercion in eugenics.

Natural selection together with the compassionate society results in an increase in the proportion of “unfit” individuals (physical, mental or behavioural) in the population. But we take no measures to compensate for this by increasing the genetic excellence of succeeding generations.

Natural selection is just not good enough. It can no longer keep up with the pace of change and it is not compatible with a compassionate society. Non-coercive eugenics seeking excellence, not just to compensate for the increasing number of the unfit, but mainly to improve the human condition, is necessary.



Breeding for intelligence?

Is human intelligence declining?


Political correctness is based on fear and a lack of values

January 5, 2016

Offense is ultimately in the minds of those who take offense.

A female (but far from androgynous) MP in the UK wants passports and driving licences to exclude the gender of the holder. “Gender – neutral” is apparently the politically correct term. I suppose a photograph which could be taken as an unflattering or gender-defining image could also be banned.

Maria Miller (Getty)

Maria Miller (Getty)

Passports and driving licences should not state if the holder is male or female to avoid causing issues for transgender people, a former Tory cabinet minister has said. Maria Miller, the former culture secretary and chair of the new women and equalities committee, said the Government should “strip back” talking about gender unless it was necessary.

Even the Washington Post actually finds something half-good to say about Donald Trump

Why Trump may be winning the war on ‘political correctness’
Cathy Cuthbertson once worked at what might be thought of as a command post of political correctness — the campus of a prestigious liberal arts college in Ohio.
“You know, I couldn’t say ‘Merry Christmas.’ And when we wrote things, we couldn’t even say ‘he’ or ‘she,’ because we had transgender. People of color. I mean, we had to watch every word that came out of our mouth, because we were afraid of offending someone, but nobody’s afraid of offending me,” the former administrator said. ……. One thing is clear: Trump is channeling a very mainstream frustration.In an October poll by Fairleigh Dickinson University, 68 percent agreed with the proposition that “a big problem this country has is being politically correct.” It was a sentiment felt strongly across the political spectrum, by 62 percent of Democrats, 68 percent of independents and 81 percent of Republicans. Among whites, 72 percent said they felt that way, but so did 61 percent of nonwhites.

“People feel tremendous cultural condescension directed at them,” and that their values are being “smirked at, laughed at” by the political and media elite, said GOP strategist Steve Schmidt.

In Stockholm, the Managing Director of the Kulturhuset City Theatre overruled his Cultural Director to ban the title of a work by an artist (Makode Linde) called “The Return of the Negro King”. 
The gender axis of the human species may be a continuum but it is bimodal. Gender is part of an individual’s identity – like it or not.
Bimodal gender Blackless et al

Bimodal gender Blackless et al

I find nothing wrong in using “negro” as an adjective or in stating that women are attractive (mostly). No doubt that is sexist. “Mongolian” and “Eskimo” and “Chinese” or “Indian” are descriptive. The word gora (pink) is used in Hindi to describe white people and is primarily descriptive. Tall people remain tall and pink people remain pink whether the adjective is politically correct or not. Adjectives describe. As long as the description is not false, offense can only be taken in the minds of those offended. I am not supposed to express my convictions that while most religions can be twisted to give support to the use of violence, Islam today does that better than most. Feminism is (or should be) about combating the unfairness of prejudice not about denying femininity. Gender difference exists and cannot be legislated away. “Affirmative action” and “reservations” try to use unfair practices to try and compensate for some other unfair practice. (In actuality they only entrench either the original unfair practice or the compensating one). It is not correct to admit that intelligence is affected by genes (race) but it is perfectly acceptable to state that running the 100m is.

Political correctness is colourless, sexless, emotionless and without values. Not referring to race and gender and religion may avoid thin-skinned and frightened people from taking offense, but it does not remove the realities of race and gender and religion. The point of having values is to use them to make judgements. Political correctness is mindless. It is censure. It displays fear not courage.


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.

Europe’s refugees just follow the ancient routes for the peopling of Europe in the Neolithic

September 17, 2015

Compared to the population of Europe of 740 million (500 million in the EU), the total refugee numbers of some 400,000 are not large enough to talk about “invasions” or being “over-run”. (In the short-term numbers may, of course, be locally overwhelming). But the routes being travelled now are the same routes that were used for the peopling of Europe in the neolithic. Neanderthals probably retreated westwards as the hunter gatherers from central Asia arrived. They had been absorbed and were long gone as a separate “race” by the time the 2 main agricultural waves arrived.

And now the refugee numbers are beginning to be large enough to be a not insignificant impact on the populations of Europe. It could well be a new “peopling of Europe”. Or it could turn out to be not so large or important. But history will probably show that the migrations of peoples into Europe in the early 22nd century was of similar importance to the neolithic migrations. History will probably show that this  migration is what stemmed the downward population spiral that was troubling Europe.

In ancient times –

First came the movement of peoples westwards into Europe. This was during the paleolithic some 40,000 – 20,000 years ago with hunter-gatherers coming from the east. The “admixture” events between the Neanderthals and modern humans could have been along the westward moving front.

Then came the advent of agriculture, starting earlier but in earnest perhaps about 10,000 years ago. Genetic evidence indicates 2 waves of farmers from the east who then mixed with the hunter-gatherers already there.

So it would seem that hunter-gatherers mixed with farmers from the east who spread across Europe about 9,000 years ago. They formed the first agricultural settlements. Then came the invasion of the nomadic Yamnaya culture around 5,000 years ago. The Yamnayans were much more individualistic than the peoples they replaced and gave rise to the prominence of the nuclear family and the development of large family holdings of cleared lands, rather than the clusters of people in village settlements. They came on horses and brought livestock. But by about 4,000 years ago they too were overrun by the warlike Sintashta.

peopling of europe in the neolithic - via daily mail

peopling of europe in the neolithic – via daily mail

and now the current refugee crisis has about 400,000 people moving north westwards –

Business InsiderAccording to the United Nations Human Rights Council (UNHRC), EU countries received 437,384 asylum applications from January to July. The UNHRC also reports that during that time, Germany was by far the country that received the most asylum applications, with 188,486. Hungary came second in place with 65,415 applications, and Sweden took third with 33,234 applications. Italy was fourth with 30,223, and France was fifth with 29,832 demands. Many refugees fleeing the Syrian civil war and ISIS have been entering the European Union through Greece — 258,365 refugees entered Greece by boat so far this year — after going through Turkey.

europe's refugee crisis - business insider graphics

europe’s refugee crisis – business insider graphics

Nothing new under the sun.

Gene mixing promotes height and intelligence – but is this an evolutionary benefit?

July 2, 2015

A new international study of the genetic make up and physical characteristics of 350,000 people indicates that greater genetic diversity leads to an increase of height and cognitive skills. But – somewhat surprisingly – lower genetic diversity did not lead to any visible increase in complex diseases. Genetic diversity was found to have no effect on blood pressure or cholesterol levels.

But I question the assumption that increased height and faster thinking are of “evolutionary advantage”. Evolutionary advantage must lead to an individual having a greater number of offspring than one without the advantage. Previous work has indicated that both child nourishment and genetics determine height.

And so I wonder what evolutionary advantage height may have in modern society? Does the ability to think faster lead to a greater number of surviving descendants? Richer and “more intelligent” groups tend to have much lower fertility rates than poorer, “less intelligent” groups.

Using the criterion of greatest surviving descendants indicating evolutionary advantage, leads to the conclusion that populations in Africa with the highest population increase rates must also have the greatest evolutionary advantages!

Peter K. Joshi et al. Directional dominance on stature and cognition in diverse human populations. Nature, 2015 DOI: 10.1038/nature14618

Abstract: Homozygosity has long been associated with rare, often devastating, Mendelian disorders, and Darwin was one of the first to recognize that inbreeding reduces evolutionary fitness. However, the effect of the more distant parental relatedness that is common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power. Here we use runs of homozygosity to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts, and find statistically significant associations between summed runs of homozygosity and four complex traits: height, forced expiratory lung volume in one second, general cognitive ability and educational attainment (P < 1 × 10−300, 2.1 × 10−6, 2.5 × 10−10 and 1.8 × 10−10, respectively).

University of Edinburgh Press Release:

People have evolved to be smarter and taller than their predecessors, a study of populations around the world suggests. Those who are born to parents from diverse genetic backgrounds tend to be taller and have sharper thinking skills than others, the major international study has found. Researchers analysed health and genetic information from more than 100 studies carried out around the world. These included details on more than 350,000 people from urban and rural communities.

The team found that greater genetic diversity is linked to increased height. It is also associated with better cognitive skills, as well as higher levels of education. However, genetic diversity had no effect on factors such as high blood pressure or cholesterol levels, which affect a person’s chances of developing heart disease, diabetes and other complex conditions.

Researchers from the University of Edinburgh examined individuals’ entire genetic make-up.

They pinpointed instances in which people had inherited identical copies of genes from both their mother and their father – an indicator that their ancestors were related. Where few instances of this occur in a person’s genes, it indicates greater genetic diversity in their heritage and the two sides of their family are unlikely to be distantly related. It had been thought that close family ties would raise a person’s risk of complex diseases but the researchers found this not to be the case.

The only traits they found to be affected by genetic diversity are height and the ability to think quickly.


Boozy chimps, Hanuman and the “drunken monkey” hypothesis

June 11, 2015

A new paper reports on chimpanzees in Guinea exhibiting long-term and recurrent ingestion of ethanol. The study was carried out over 17 years and found chimpanzees using leaves to drink fermented palm sap. Many consumed sufficient to produce “visible signs of inebriation”. Local humans also tap the sap of the raffia palm trees to make a palm wine.

The human trait of imbibing intentionally fermented drinks is at least as old as the oldest known archaeological records of ancient civilizations. Stone jugs for alcoholic drinks have been found which date back to at least 10,000 BCE . It is quite likely that the origin of alcoholic drinks predates the arrival of agriculture some 15,000 years ago. And that would suggest that the origin lies with the accidental (and fortuitous?) consumption of over-ripe and partially fermented fruits and berries leading eventually to an intentional fermentation. But that takes the origin back to the time before modern humans had even arrived on the scene and when their primate ancestors relied on fruits and berries for their diet.

Kimberly J Hockings, et al, Tools to tipple: ethanol ingestion by wild chimpanzees using leaf-sponges, Royal Society of Open Science

AbstractAfrican apes and humans share a genetic mutation that enables them to effectively metabolize ethanol. However, voluntary ethanol consumption in this evolutionary radiation is documented only in modern humans. Here, we report evidence of the long-term and recurrent ingestion of ethanol from the raffia palm (Raphia hookeri, Arecaceae) by wild chimpanzees (Pan troglodytes verus) at Bossou in Guinea, West Africa, from 1995 to 2012. Chimpanzees at Bossou ingest this alcoholic beverage, often in large quantities, despite an average presence of ethanol of 3.1% alcohol by volume (ABV) and up to 6.9% ABV. Local people tap raffia palms and the sap collects in plastic containers, and chimpanzees use elementary technology—a leafy tool—to obtain this fermenting sap. These data show that ethanol does not act as a deterrent to feeding in this community of wild apes, supporting the idea that the last common ancestor of living African apes and modern humans was not averse to ingesting foods containing ethanol.

The study provides support for the “drunken monkey” hypothesis which “proposes that human attraction to ethanol may derive from dependence of the primate ancestors of Homo sapiens on ripe and fermenting fruit as a dominant food source. Ethanol naturally occurs in ripe and overripe fruit when yeasts ferment sugars, and consequently early primates (and many other fruit-eating animals) have evolved a genetically based behavioral attraction to the molecule”.

In fact there were natural selection benefits in being “drunken monkeys”. The chimpanzee paper begins:

The ‘drunken monkey hypothesis’ states that natural selection favoured those primates with an attraction to ethanol (commonly referred to as alcohol) because it was associated with proximate benefits (e.g. acting as an appetite stimulant or a cue to finding fruit, or as an unavoidable consequence of a frugivorous diet, etc.), consequently increasing caloric gains.

Hanuman chasing the Sun — image Wikipedia

It is a short mental step from monkey-ancestors to ancient civilizations and mythology. The Indian monkey-god, Hanuman was supposed to be both celibate and teetotal. But his depiction as a “monkey” is probably a later invention. Ancient texts suggest that the young Hanuman was so enamoured of red fruit that he tried to eat the Sun, thinking it was just another ripe fruit. Quite possibly his red fruit were over-ripe, partially fermented and intoxicating. The resulting disfigurement to his jaw and face (burnt and swollen) is what may have given him his appearance. There is a hint that he was of an ancient people (species), half-human and half-monkey, which has become extinct. An ancient ancestor perhaps, and one addicted to intoxicating fruit. Clearly he was put off alcohol for ever. Interestingly, mythology and ancient ayurvedic medicine agree that alcohol in moderation is medicinal and good but taken in excess is a poison and bad. Of course in the Ramayana, all the good guys are vegetarians and teetotal while all the bad guys eat meat and consume an excess of alcohol. The Mahabharata is much more equivocal. Here even the good guys are allowed to drink.

Indian-American domination of the Spelling Bee – by the numbers

May 29, 2015

The domination of the Spelling Bee by Indian-Americans continues. It resembles the domination of long distance running events by East Africans. It is highly unlikely that a genetic component is not involved.

Vanya Shivashankar of Olathe, Kansas, and Gokul Venkatachalam, St. Louis, Missouri lift the trophy after becoming co-champions after the final round of the 88th annual Scripps National Spelling Bee at National Harbour, Maryland on Thursday.

  1. Vanya Shivashankar and Gokul Venkatachalam, both 8th graders, jointly won the 88th Scripps Spelling Bee.
  2. Vanya is the first sibling of a past champion to win, with her sister, Kavya, winning in 2009.
  3. 285 spellers took part in the 88th US Scripps Spelling Bee competition.
  4. They came from the 50 U.S. states, American Samoa, Guam, Puerto Rico, the U.S. Virgin Islands, and Department of Defense Schools in Europe, the Bahamas, Canada, China, Ghana, Jamaica, Japan and South Korea.
  5. Though Indian-Americans make up just 1% of the nations population, they (64 or 65) constituted more than 20% of the Spelling Bee contestants .
  6. Three contestants, all of Indian origin, Vanya Shivashankar, Jairam Hathwar, and Srinath Mahankali, had siblings who have previously won the Scripps National Spelling Bee.
  7. Indian Americans have won for seven years in a row and all but four of the last 15 years.
  8. At the semi-final stage 29 of the 50 contestants were Americans of Indian origin.
  9. Seven of the ten finalists were Indian Americans.

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