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A mathematical approach to the demise of the Neanderthals.

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Pure mathematics is, in its way, the poetry of logical ideas. Albert Einstein.

I have never been proficient at mathematics. But that doesn’t mean that I am not fascinated by the field of maths.

Hold that in your thoughts as I mention the name of blogger: Patrice Ayme.  It’s a non-de-plume but so what!  What blows me away, to use the vernacular, is the depth of thought expressed through the keyboard of Mr. Ayme (even the gender is an assumption).  The sub-heading on the home page of his blog is “Intelligence at the core of humanism“.  Just run your eye down the list of Recent Posts to the right-hand side of the home page to get a feel for the topics covered in the last few months.  Impressive is an understatement!

Anyway, five days ago Patrice published a post proposing how the Neanderthals were outbred, under the title of Math Extinguished Neanderthals.  It fascinated me and Patrice was gracious in allowing me permission to republish it on Learning from Dogs.

oooOOOooo

Math Extinguished Neanderthals

HOW NEANDERTHALS WERE OUTBRED:

Zillions of theories about the “disappearance” of Neanderthals. The latest one, from Oxford University, claims that Neanderthals’ big, beautiful eyes, and their big muscles caused their demise. They were too busy looking at things, and flexing their muscles. The idea is that significantly larger eyes would have crowded the Neanderthal brain out, making them relatively stupid. In particular it made them incapable of having social groups as large as those of Homo Sapiens Sapiens.

Big Eyes Do Not Kill

Big Eyes Do Not Kill

Sapiens girl on the left, Neanderthal girl on the right (reconstitution published in Science Magazine a few years ago).

I have long argued that the strength of democracy came from having many brains working in parallel. There is little doubt that larger social groups bring a higher cultural intelligence, hence higher individual intelligence. So I agree about that bit of logic. Yet, ironically, to reach the conclusion that Neanderthals’ social group were less numerous, the simple fact that Neanderthals were bigger, is enough. There is no need for hazardous demeaning allegations about Neanderthals’ brains.

That big eyes made Neanderthals stupid contradicts some facts that were thought to be established:

1) Sapiens Neanderthalis’ brains were significantly larger to start with. See Wikipedia.

2) Many very clever Homo Sapiens Sapiens have small brains. Famously Anatole France, an intellectual, had only a 1,000 cubic centimeters brain. Homo Floresiensis, the “hobbit” species living on the island of Flores, Indonesia, until it was wiped out recently, was extremely intellectually capable, although it had really small (and completely different) brains.

3) In the Middle East, Neanderthals and Sapiens went back and forth through the same large caves over 50,000 years. So whatever happened, it was not in evidence for 50,000 years.

So, of course, I have my own theory. That’s what philosophy is all about: trying to guess what really matters most, and how that most significant data logically articulate. Then scientists, politicians and writers can swoop, figure out the details, and attribute themselves the glory.

What could have happened by around 28,000 years ago that caused the demise of Neanderthals? At the time, the last fierce glaciation was gaining ground. (It reached its maximum 25,000 years ago.) Some have argued, absurdly, that the Neanderthals could not take it. That’s beyond silly, as Neanderthals had evolved, from half a million years ago, precisely to handle extreme cold.

Neanderthals were stocky, powerful, and they had thrived through hundreds thousands years of glaciation, mostly on a meat diet, hunting big game. But they also knew how to cook plants, and eat them.

50,000 years ago, Neanderthals exterminated Cave Bears, a huge animal who lived in caves, prime real estate Neanderthals craved for. Could the disappearance of Cave Bears be logically linked to the disappearance of Neanderthals? Yes. That’s a consequence of my theory. More advanced technology played a direct role.

How did Neanderthals kill Cave Bears? With technology. We do not know exactly what weapons Neanderthals had at their disposal. However, technology had improved, and kept improving. Recently it was found that Sapiens Sapiens (Homo SS; I hope one gets the joke) in Africa had invented bows and arrows 80,000 Before Present (BP).  (About 60,000 years earlier than previously thought!) Before bows and arrows, the propeller had been invented, and was used in Europe. The propeller took advantage of angular momentum to send a sort of mini lance further and stronger than by hand.

Why did the Neanderthals and Denisovans (another human species from Central Eurasia) lose their edge? Advancing technology is the obvious answer. When technology of clothing and weapons was sufficiently advanced, the physiological advantage that the Neanderthals genetically had, disappeared. Homo Sapiens Sapiens could thrive just as well through winter.

At that point, Homo Sapiens Sapiens from Africa could be as successful as the Neanderthals through the freezing wastelands of Europe. OK.

But the Homo SS outbred the Neanderthals, so they became genetically more successful. How do I explain that?

Simple. However, the explanation involves the exponential function, the same function found all over, and that the mathematician Rudin called “the most important function in mathematics”. The exponential also explains the plutocratic phenomenon, and that is why it’s so dangerous. The exponential always rules extinction events, that’s why one day a species is all over, like the American Pigeon, or the Tasmanian Tiger, and the next day, it’s gone.

So visualize this. Neanderthals were bigger than Homo SS, just like the Polar Bear is bigger than the Black Bear. Bigness is an adaptation to cold. Southern Europe’s Brown Bears are smaller than those found in Kamchatka, or Alaska (also known as Grizzlies: the Grizzly is an emigrated European Brown Bear!) Bigger makes warmer inside. That’s why the most massive animal that ever was, the Blue Rorqual, at up to 180 tons, is nearly twice the mass of the largest dinosaur (it’s not just that it’s floating, but also that water is cooler than Jurassic air, I hold).

To simplify, let’s use a bit of exaggeration (that’s reasoning by exaggeration, one of my preferred tactic of thought; the one humor exploits, and why joking helps thinking). Let’s assume Neanderthals were twice more massive than Homo SS.

Now let’s consider an habitat where Homo SS and Neanderthal bands roamed. They will tend not to mix, for obvious racist reasons. The racial hatred between Neanderthals and Homo SS has got to have been colossal. People who look too different are not even sexually attracted to each other (and where Neanderthals and Homo SS were in contact in the Middle East, for 50,000 years, there is no evolution of an interbred species, an indirect proof that there was no love lost there!)

The density of human mass is going to be roughly the same all over, because that density depends only upon the resources available (mostly meat on the hoof, and fur in burrows in glaciating conditions).

Thus, there would have been apartheid. But the Homo SS would have been twice more numerous, where they reigned (from my assumption of twice the mass). So now graft on this a catastrophe; a drought, a flood, a very tough winter, a volcanic super disaster, whatever. The climate was highly variable, starting about 40,000 years ago, just when Homo SS appeared. Some have stupidly argued that Neanderthals were too stupid to adapt to this changing circumstances. Like this paralyzing stupidity struck them just when Homo SS were around. My explanation is more subtle.

After a catastrophe in said habitat, say one of these numerous habitat in Europe isolated by glacial mountain ranges, or seas and lakes, most of the human population would be wiped out, Homo SS, just as Neanderthals. There would tend to be always a small remaining population, because the greatest limit on man is man himself: as a population gets wiped out, resources rebound, and life of the survivors tend to get much easier (that’s what happened in Europe after the Black Death of 1348 CE; if nothing else, survivors could ask for higher salaries from their plutocratic masters, and they did).

So say 90% of the population of the habitat was wiped out. As suddenly resources are now not limited, the human population will rebound exponentially. The equation is: N(t) = N(0) exp(Rt). “R” is the “Malthusian” parameter, the rate of growth. Now it’s going to require twice the resources to feed a Neanderthal to sexual maturation (under our outrageously simplifying assumption that Neanderthals are twice the mass). Thus one may assume that R(Homo SS)/R(Neanderthal) is 2. The end result is that the quotient:

Number Homo SS/ Number Neanderthal = A exp(2t). (Where A is the ratio of the populations H SS/Neanderthal after the catastrophe.)

Thus the population of H SS would exponentially grow relative to that of the Neanderthals, resulting in a quick extinction. And in no way this is happening because Homo SS were superior. Just because they were more gracile.

Hence the mystery of the evolution of contemporary man is smoothly explained. Just a bit of math. QED.

Europeans & Asians: Not Just African

Europeans & Asians: Not Just African

***

Patrice Ayme

***

Note 1: what of the mentally deliquescent and racist article in the Proceedings of the Royal Society? First, they sank so low as tousing orbit size as a proxy, that Neanderthals had larger visual systems than contemporary AMH [Anatomically Modern Humans]. That’s about as intelligent as saying that, because special forces use night vision goggles, they have got to have bigger visual systems.

The main woman author also found the same physiological feature, bigger eyes, in the past, about people presently living at high latitude. She contentedly asserted that, because light levels are lower in the north, people living in the north (40,000 years at least for Homo SS) have bigger eyes. Amusingly, she did not draw, in that case the conclusion that Norwegians and the English are therefore more stupid. Somehow, though, in her lack of smarts, she applies that controversial reasoning to Neanderthals. Does she have giant eyes?

Seriously the Oxford study rests on a central fact that contradicts one of established facts about Neanderthals. Indeed it claims Neanderthals’ brains were not any larger than Homo SS.

***

Note 2; what catastrophes am I talking about? Well the climate fluctuated wildly, to start with. Second, A Campanian ignimbritevolcanic super-eruption around 40,000 years ago, followed by a second one a few thousand years later, certainly crashed Neanderthal populations (based on logic, and evidence fromMezmaiskaya cave in the Caucasus. Mitochondrial DNA analysis of a specimen there is C14 dated 29,000 years BP, one of the latest living pure Neanderthals). After such a catastrophe, the exponential rebounds of populations would have advantaged Homo SS, as explained above.

***

Note 3: OK, I exaggerated with the mass ratio. (Mathematicians often do this, considering an exaggerated case to understand the mean, through the tails.) But the real mass ratio would be aggravated because, Neanderthal was built in such a way, relative to gracile Homo SS, that they consumed more calories per day (some paleontologists have come up with 300). So there is no doubt that the effect above will play a role, even if the mass ratios were not as bad. Notice the mechanism above would tend to extinguish the Neanderthal traits that were most characteristic of the subspecies.

***

Note 4: A preferred trick of Neanderthals’ haters is to exhibitArchaic Neanderthals‘skulls, and compare them to those of modern men. The skull of an Archaic Neanderthal of 400,000 years ago should not be compared to a modern human, less than 40,000 year old! All the more since Neanderthals’ brain size augmented faster than the brain size of Homo Sapiens Sapiens.

***

Note 5: Part of the mechanism above generalizes for other species in competition. It provides with a disappearance mechanism after ecological turbulence, according to species’ ecological footprint.

oooOOOooo

So hope that others shared my pleasure at reading the essay.

Going to close with another quotation from Mr. Albert Einstein: “As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality.”

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Written by Paul Handover

March 19, 2013 at 00:00

Toba

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An unbroken record for two million years!

I came across this previously unknown, well to me, volcanic eruption during my research on my Vesuvius article for last week.  In that article I mentioned that I would discuss this truly giant eruption at a later date.

If your general knowledge is sufficiently good to know exactly what I am referring to, both in the title, Toba, and the sub-heading, then well done!  So to those that do know about the Toba volcanic eruption, my apologies.  To all you others, read on.

The Toba volcano produced the largest known volcanic eruption on earth during the past 2 million years.

Here’s an extract from the website Articles Extra,

Toba almost wiped out mankind 73,000 years ago. Back then Neanderthal man inhabited our Earth alongside Homo sapiens in Europe, Homo erectus and the recently discovered Homo floresiensis in Asia. It was cold in Europe, the last ice age was in full swing and reindeer, wild horses and giant stag were hunted in our breadths. Alongside the herbivorous nourishment, mammouth and woolly rhinos were occasionally on the menu for humans when Toba, with a diameter of 90 kilometres on the island known today as Sumatra, in the truest sense of the word, “blew up”.

A volcanic eruption with a diameter of 90 kilometres!  Ouch!  Back to the article,

Alongside gigantic Tsunami waves, there was the unimaginable amount of 2800 cubic kilometres of ejected ash, which, evenly spread throughout our planet’s atmosphere, should have reduced the total number of humans to just 5000 to 10,000 survivors, as the Australian vulcanologist Prof. Ray Cas explains in an interview: “The suns rays only weakly reached the ground all around the globe, plants received too little light, the average temperature dropped to 5 degrees, so that summer turned to winter and winter became deadly in Verbindung.”

Two thousand, eight hundred cubic kilometres of ejected ash!  It’s practically impossible to get one’s mind around that figure.  OK, it’s easy enough to look up the volume of just one cubic kilometre – it’s 1,000,000,000 m3 or a trillion litres!  Or for those of you in old money, as 1 US Gallon is the equivalent of 3.785 litres, then a trillion litres is 264,200,792,602 US gallons!   Approximately 264 billion US gallons!   264 billion US gallons which, in case you missed it, is just one cubic kilometre.  Toba ejected 2,800 times that amount in ash!

Back to the article,

Today we know that humans and their near relatives survived this global Armageddon of nature in small groups, mainly in Africa. It is incredible how scientists found all of that out with the help of thousands of DNA studies of today’s humans. Mag. Bence Viola from the Anthropological Institute of Vienna University: “We examined the DNA in human mitochondria, the powerhouse of cells, and thereby observed that the genetic composition in samples from humans from all over the world had to have been much more different if Homo sapiens were able to have developed in all parts of the Earth without problems.”

Actually today’s humans originate from a few thousand survivors and we can attribute the cause to the eruption of the super volcano Toba around 73,000 years ago. So it is a sort of genetic bottleneck, through which not only Homo sapiens had to have been forced, but also all of his relatives that were still living at that time but who died out later on due to other reasons.

Therefore a volcano in the region of Indonesia was responsible for the near destruction of mankind. From the 60 to 70 volcanoes that are to be found in the area today, a remarkable number have become active again in the weeks and months after the seaquake in December. Yet Toba is dozing today deep and safe under a huge sea bearing the same name in Northern Sumatra. Many people fear that if the suddenly active volcano of Talang that lies 300 kilometres south erupts, it could awaken the deadly giant.

Vulcanologist Prof. Ray Cas

Vulcanologist Prof. Ray Cas: “That could actually happen, but only if Toba were ready to erupt and at the moment there is not the slightest indication of that.” The expert does think that it is probable that one day another huge eruption will take place: “But that can only happen in 10,000 or even 100,000 years. The Earth is despite all efforts not predictable.”

It remains furthermore open to know what would happen to us in the face of such a devastating natural disaster, if a volcanic eruption similar to Toba were imminent. The way things stand today we cannot do anything against it.

Let’s close this reflection on a truly earth-changing event by looking at a picture of Toba today,

The Toba volcanic caldera as of today.

Written by Paul Handover

August 30, 2011 at 00:00

Two years today!

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Learning from Dogs first saw the light of day two years ago.

It all started on July 15th, 2009, during a very hot summer down in San Carlos, Mexico where I was first living with Jean.

Now, some 1,000 posts later life is very different.  Jean and I are now married and living incredibly happily, with our twelve dogs and six cats, in Payson, Arizona, some 80 miles NE of Phoenix, up at 5,000 feet on the fringe of the world’s largest Ponderosa Pine forest.

Ponderosa pine forest

So apologies if today’s Post is partly reflective on the last two years.  It also seems appropriate to revisit the reasons why so many articles on the Blog aren’t about dogs.

I feel the need to do that because the number of new readers now is just staggering.

The first full month was August 2009.  Wordpress stats reveal that there were 1,172 unique viewers of the Blog.  The last full month was, of course, June 2011.  Wordpress figures were 31,664 unique viewers!  That’s over a 1,000 viewers a day, and the trend is still upwards!

I am, of course, deeply moved by this response.  Thank you, one and all!

In writing Learning from Dogs, I have tried to stay close to the theme that dogs are a metaphor for change for mankind.  But that doesn’t mean that this is a doggy Blog.

As I wrote on the Welcome page, “Dogs live in the present – they just are!  Dogs make the best of each moment uncluttered by the sorts of complex fears and feelings that we humans have. They don’t judge, they simply take the world around them at face value.”

Learning from Dogs is a Blog about the fundamental truths that we need to be reminded of, for our long-term survival. Dogs teach us the importance of integrity, of faith and loyalty and of unconditional love.

But just as importantly, dogs are a reminder that our evolution to Neolithic man may have been an evolutionary mistake.  Stay with me for just a while.

Dogs were domesticated a mind-numbing number of years ago.  There is good evidence that dogs were co-operating with man 30,000 years ago.  However, one might speculate why the DNA of the dog separated from the grey wolf approximately 100,000 years ago.  Was it because they evolved even that far back as domesticated companions to man?  Science can’t tell us that yet.

But 30,000 years ago man was most definitely a hunter-gatherer.  Archaeologists have pondered whether the domesticated dog allowed man to be so successful as a hunter-gatherer that, in time, man was able to evolve into farming which, of course, we describe more accurately as the Neolithic Revolution.

Here’s an extract from WikiPedia,

The ”Neolithic” Revolution is the first agricultural revolution—the transition from hunting and gathering to agriculture and settlement. Archaeological data indicate that various forms of domestication of plants and animals arose independently in six separate locales worldwide ca. 10,000–7000 years BP (8,000–5000 BC), with the earliest known evidence found throughout the tropical and subtropical areas of southwestern and southern Asia, northern and central Africa and Central America.

However, the Neolithic Revolution involved far more than the adoption of a limited set of food-producing techniques. During the next millennia it would transform the small and mobile groups of hunter-gatherers that had hitherto dominated human history, into sedentary societies based in built-up villages and towns, which radically modified their natural environment by means of specialized food-crop cultivation (e.g., irrigation and food storage technologies) that allowed extensive surplus food production.

These developments provided the basis for concentrated high population densities settlements, specialized and complex labor diversification, trading economies, the development of non-portable art, architecture, and culture, centralized administrations and political structures, hierarchical ideologies and depersonalized systems of knowledge (e.g., property regimes and writing).

There’s one sentence that just jumps off the ‘page’.  It’s this one. “During the next millennia it would transform the small and mobile groups of hunter-gatherers that had hitherto dominated human history

Here’s a quick bit of history about Homo Sapiens, from here,

Neanderthal man: from 230,000 years ago

Around 250,000 years ago Homo erectus disappears from the fossil record, to be followed in the Middle Palaeolithic period by humans with brains which again have increased in size. They are the first to be placed within the same genus as ourselves, as Homo sapiens(‘knowing man’).

By far the best known of them is Neanderthal man — named from the first fossil remains to be discovered, in 1856, in the Neander valley near Dusseldorf, in Germany. The scientific name of this subspecies is Homo sapiens neanderthalensis. The Neanderthals are widely spread through Europe and the Middle East, and they thrive for an extremely long period (from about 230,000 to 35,000 years ago). Bones of animals of all sizes, up to bison and mammoth, and sophisticated stone tools are found with their remains.

Thus as a species we, as in H. sapiens, survived for approximately 200,000 years as hunter-gatherers!

Now after just 12,000 years, give or take, as ‘farmers’ we are facing the real risk of extinction. Go back to that WikiPedia extract above and re-read “concentrated high population densities settlements, specialized and complex labor diversification, trading economies, the development of non-portable art, architecture, and culture, centralized administrations and political structures, hierarchical ideologies and depersonalized systems of knowledge (e.g., property regimes and writing)“.

If you want to fully comprehend the mess we, as in man, have got ourselves into, then watch the stunning movie What a Way To Go: life at the end of the empire.  That movie website is here or you can watch it from here.  (I will be reviewing the film on Learning from Dogs in the next couple of weeks.)

The filmmakers, Tim Bennett and Sally Erickson, towards the end of the film muse if mankind must go back to some form of hunter-gatherer society, not literally, of course, but ‘back’ to a form of society that is fundamentally sustainable with the world upon which we live.  As successful as Neanderthal man.  Here’s where dogs may have critically important lessons for mankind.

  • Dogs form small packs, up to a maximum of 50 animals
  • They have a simple hierarchy within the pack; the alpha female (who has first choice of breeding male and makes the very big decisions about whether the pack should move to a better territory), the beta male (always a dominant male that teaches the young pups their social skills and breaks up fights within the pack – my Pharaoh, as seen on the home page, is a beta GSD), and the omega dog (the clown dog, male or female. whose role is to keep the pack happy through play).
  • They survive through an extraordinary relationship with humans but if they have to revert to the ‘wild’ they survive as hunter-gatherers.

Maybe humans, at heart, also share certain similar characteristics:

  • We are happiest in social groups of less than 50
  • We much prefer simple methods of group order, where rules and discipline are managed within the group.  (Think about how easily we form all sorts of local clubs and groups.)
  • A ‘local’ approach to survival through deep and extensive group co-operation would be so much more effective than what most of us presently experience in our societies.

That’s why so many of the articles that appear on Learning from Dogs focus on the madness of what we experience so often in our present enormous, faceless, distant societies.

Back to Sally Erickson, one of the film makers mentioned earlier.  Here’s what she wrote in her Blog

Our world is in need of healing at every level. We as a species aren’t going to survive, the way we are going. If we don’t heal ourselves, evolve a new consciousness, and fundamentally change the way we live, human beings won’t make it.

Where’s it all heading?  Who knows?  I am reminded of that wonderful quote attributed to Niels Bohr but, more likely, from an unknown author (although Mark Twain is often suggested), “Prediction is very difficult, especially about the future.

Happy Birthday, Learning from Dogs.  Thank you to all of you that have supported this venture over the last two years.

What is the dog?

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Time to attempt an answer to this fundamental, well for this Blog, question!

 

Like wolves, the Dingo is smarter than pet dogs.

(The above photograph comes from an article on ImpactLab – see foot of Post for more details.)

When putting together the Blog ahead of the publication of the very first Post on July 15th, 2009, some 820 Posts ago, I prepared some additional material that set out to justify the Raison d’être for the venture.  Included was a piece regarding Dogs and integrity.  There I wrote:

Dogs are part of the Canidae, a family including wolves, coyotes and foxes, thought to have evolved 60 million years ago.  There is no hard evidence about when dogs and man came together but dogs were certainly around when man developed speech and set out from Africa, about 50,000 years ago.  See an interesting article by Dr. George Johnson.

Anyway, I revisited the article written by Dr Johnson and thought it worthy of being published in full, as a separate article in Learning from Dogs.  I requested permission to reproduce the article in full and Dr. George Johnson was very gracious in quickly coming back to me giving his agreement.  Thank you.  The original article can be read here, the ONSCIENCE home page is here and Dr. Johnson’s details are here.

Evolution of the family dog

I first suspected that Boswell would have a short life when he bit my wife on our nuptial bed.

Boswell was my dog, a feisty Toto-like terrier who shared my bachelor bed and resented the intrusion of a woman where he felt a dog — Boswell — ought to be. As it turns out, my suspicion was correct, and he did not live out the year, which was 1982. Staying with others while I and my bride were overseas, Boswell resented being denied chicken bones, ate them anyway, and died of the consequences. To this day I miss him.

This week I found myself wondering about Boswell’s origins. From what creature did the domestic dog arise? Darwin suggested that wolves, coyotes, and jackals — all of which can interbreed and produce fertile offspring– may all have played a role, producing a complex dog ancestry that would be impossible to unravel. In the 1950s, Nobel Prize-winning behaviorist Konrad Lorenz suggested some dog breeds derive from jackals, others from wolves.

Based on anatomy, most biologists have put their money on the wolf, but until recently there was little hard evidence, and, as you might expect if you know scientists, lots of opinions.

The issue was finally settled in 1997 by an international team of scientists led by Robert Wayne of the University of California, Los Angeles. To sort out the evolutionary origin of the family dog, Wayne and his colleagues used the techniques of molecular biology to compare the genes of dogs with those of wolves, coyotes and jackals.

Wayne’s team collected blood, tissue, or hair from 140 dogs of sixty-seven breeds, and 162 wolves from North America, Europe, Asia, and Arabia. From each sample they extracted DNA from the tiny organelles within cells called mitochondria.

While the chromosome DNA of an animal cell derives from both parents, the mitochondrial DNA comes entirely from the mother. Biologists love to study mitochondrial DNA because of this simple line of descent, female-to-female-to-female. As changes called mutations occur due to copying mistakes or DNA damage, the mitochondrial DNA of two diverging lines becomes more and more different. Ancestors can be clearly identified when you are studying mitochondrial DNA, because clusters of mutations are not shuffled into new combinations like the genes on chromosomes are. They remain together as a particular sequence, a signature of that line of descent.

When Wayne looked at his canine mitochondrial DNA samples, he found that wolves and coyotes differ by about 6% in their mitochondrial DNA, while wolves and dogs differ by only 1%. Already it smelled like the wolf was the ancestor.

Wayne’s team then focused their attention on one small portion of the mitochondrial DNA called the control region, because it was known to vary a lot among mammals. Among the sixty seven breeds of dogs, Wayne’s team found a total of 26 different sequences in the control region, each differing from the others at one or a few sites. No one breed had a characteristic sequence — rather, the breeds of dogs share a common pool of genetic diversity.Wolves had 27 different sequences in the control region, none of them exactly the same as any dog sequence, but all very similar to the dog sequences, differing from them at most at 12 sites along the DNA, and usually fewer.

Coyote and jackal were a lot more different from dogs than wolves were. Every coyote and jackal sequence differed from any dog sequence by at least 20 sites, and many by far more.

That settled it. Dogs are domesticated wolves.

Using statistical methods to compare the relative similarity of the sequences, Wayne found that all the dog sequences fell into four distinct groups. The largest, containing 19 of the 26 sequences and representing 3/4 of modern dogs, resulted from a single female wolf lineage. The three smaller groups seem to represent later events when other wolves mated with the now-domesticated dogs. Domestication, it seems, didn’t happen very often, and perhaps only once.

The large number of different dog sequences, and the fact that no wolf sequences are found among them, suggests that dogs must have been separated from wolves for a long time. The oldest clear fossil evidence for dogs is 12,000 – 14,000 years ago, about when farming arose. But that’s not enough time to accumulate such a large amount of mitochondrial DNA difference. Perhaps dogs before then just didn’t look much different from wolves, and so didn’t leave dog-like fossils. Our species first developed speech and left Africa about 50,000 years ago. I bet that’s when dogs came aboard, when our hunter-gatherer ancestors first encountered them. They would have been great hunting companions.

I think Boswell would be happy to know his ancestor was a wolf. I doubt, however, I will ever be able to get my wife to overlook the biting as “wolf genetic baggage” inherited from nobel ancestors. In my house, science only stretches so far. © Txtwriter Inc

As so often happens, for reasons quite beyond me, when I am pursuing an article idea something else crops up that is highly relevant to my musings.  This was no exception.

A recent article in the Christian Science Monitor describes finding a fragment of dog bone in North America dating back some 9,400 years.  Here’s a flavour of that article.

By Associated Press / January 19, 2011

PORTLAND, MaineNearly 10,000 years ago, man’s best friend provided protection and companionship — and an occasional meal.

That’s what researchers are saying after finding a bone fragment from what they are calling the earliest confirmed domesticated dog in the Americas.

University of Maine graduate student Samuel Belknap III came across the fragment while analyzing a dried-out sample of human waste unearthed in southwest Texas in the 1970s. A carbon-dating test put the age of the bone at 9,400 years, and a DNA analysis confirmed it came from a dog — not a wolf, coyote or fox, Belknap said.

Because it was found deep inside a pile of human excrement and was the characteristic orange-brown color that bone turns when it has passed through the digestive tract, the fragment provides the earliest direct evidence that dogs — besides being used for company, security and hunting — were eaten by humans and may even have been bred as a food source, he said.

Belknap wasn’t researching dogs when he found the bone. Rather, he was looking into the diet and nutrition of the people who lived in the Lower Pecos region of Texas between 1,000 and 10,000 years ago.

The article then, a little later, goes on to say:

Dogs have played an important role in human culture for thousands of years.

There are archaeological records of dogs going back 31,000 years from a site in Belgium, 26,000 years in the Czech Republic and 15,000 years in Siberia, said Robert Wayne, a professor of evolutionary biology at UCLA and a dog evolution expert. But canine records in the New World aren’t as detailed or go back nearly as far.

Darcy Morey, a faculty member at Radford University who has studied dog evolution for decades, said a study from the 1980s dated a dog found at Danger Cave, Utah, at between 9,000 and 10,000 years old. Those dates were based not on carbon-dating or DNA tests, but on an analysis of the surrounding rock layers.

“So 9,400 years old may be the oldest, but maybe not,” Morey said in an e-mail.

Morey, whose 2010 book, “Dogs: Domestication and the Development of a Social Bond,” traces the evolution of dogs, said he is skeptical about DNA testing on a single bone fragment because dogs and wolves are so similar genetically.

My last extract is as follows:

Darcy Morey, a faculty member at Radford University who has studied dog evolution for decades, said a study from the 1980s dated a dog found at Danger Cave, Utah, at between 9,000 and 10,000 years old. Those dates were based not on carbon-dating or DNA tests, but on an analysis of the surrounding rock layers.

“So 9,400 years old may be the oldest, but maybe not,” Morey said in an e-mail.

Morey, whose 2010 book, “Dogs: Domestication and the Development of a Social Bond,” traces the evolution of dogs, said he is skeptical about DNA testing on a single bone fragment because dogs and wolves are so similar genetically.

Fascinating.

Finally, going back to the photograph at the top of the page, this came from an article here in ImpactLab.  It’s well worth a read.

Written by Paul Handover

January 24, 2011 at 00:00

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