Showing posts with label paleontology. Show all posts
Showing posts with label paleontology. Show all posts

Sunday, October 20, 2013

Simplified story of our origins

Creationists and folk who believe in the truth of Genesis are trying constantly to invent arguments designed to reveal that Darwinian evolution cannot be true, and that God therefore exists. A few years ago, two of these fellows created a photo montage of an imaginary animal called a crocoduck.

They argued that, if evolution were a valid theory, then this kind of transitional animal—midway between a crocodile and a duck—should have existed at some time in the past. Insofar as nobody had ever found traces of such a beast, the fellows who imagined it concluded that evolution was false, and that God had created all living creatures. But their operation completely backfired when scientists actually found traces, in 2009, of an authentic reptile with a duck-like bill: the Anatosuchus minor.

A few days ago, paleontologists announced the existence of an extraordinary hominid skull, 1.8 million years old, uncovered in Georgia at a place named Dmanisi.

Here's an artist's impression of the physical appearance of this creature.

In a more subtle way than in the case of the crocoduck, this splendid Homo specimen—designated by scientists as "the world's first completely preserved adult hominid skull"—is an apparently hybrid fossil, in the sense that it combines features that have been associated, up until now, with what were thought to be separate hominid species. This means that paleontologists will probably get around to simplifying their categories, by considering that all the alleged hominid families are merely variants of a single species, Homo erectus, which originated in Africa.

Homo Erectus couple.

Saturday, February 9, 2013

Old family portrait

In my blog post of 22 October 2011 entitled What science is saying [display], I spoke of a fabulous book for young and old alike: The Magic of Reality by Richard Dawkins. And I borrowed a couple of Dave McKean's wonderful depictions of our prehistoric ancestors. Now, those illustrations were largely figments of the artist's imagination. Today, we are offered a considerably more authoritative portrait of an immensely archaic granddaddy:

Illustration by Carl Buell

This fellow is the outcome of a lengthy study of primeval mammalian genealogy some 66 million years ago. The creature in the portrait was about the size of a rat, and it weighed about a quarter of a kilogram. Like the dormice that I mentioned in my blog post of 31 December 2012 entitled Walnut war [display], it had a bushy tail. Its scientific name is Protungulatum donnae, but I'll refer to him here as Adam.

It's important to understand that the scientists at Stony Brook University (Long Island, New York) who've just presented a picture of Adam to his living descendants did not dig him up out of the ground, as if he were a run-of-the-mill monarch in search of a horse. Nobody has ever set eyes upon an actual fossil of this "first ungulate" (hoofed beast). Instead, Adam was created virtually on the basis of a whole set of fossil specimens and evolutionary facts.

Visual data in my blog post of the day before yesterday entitled Wolf territory [display] indicates the presence of a furry hoof attached to the extremity of the bone that Fitzroy was gnawing. I wondered for a moment or two whether my dog might have unearthed a specimen of a modern descendant of Adam, but I soon realized that Fitzroy's beast was much larger than a rat. So, I was obliged to rule out the likelihood that my dog had got involved in paleontology.

Adam is looked upon as humanity's most recent common ancestor with other mammals. The scientists say he ate insects. His long furry dormouse-like tail makes me wonder if he didn't appreciate walnuts, too. One thing about Adam's appetite for fruit is certain. As revealed in a celebrated book of archaic wisdom, he acquired a taste for apples. And that's where everything got totally screwed up for the rest of eternity.

Wednesday, August 15, 2012

What, no rock 'n' roll in the caves?

Svante Pääbo, 57, is a Swedish geneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig.

In my blog post of 26 December 2010 entitled Prehistoric encounters [display], I mentioned the existence in Siberia, 30 millennia ago, of humanoid creatures—on an evolutionary par with Neanderthals—known as Denisovans. It was Pääbo's team that revealed the existence of these people, in March 2010, using mtDNA [mitochondrial DNA] that was lurking in a single Denisovan finger bone.

Two months later, Pääbo's team published a draft sequence of the Neanderthal genome. Noticing that a certain quantity of DNA is common to both Neanderthals and modern humans whose ancestors had moved beyond Africa, Pääbo's team announced that it was likely that a certain degree of sexual promiscuity had characterized relationships between Neanderthals and humans in the course of their many millennia together, side by side, on the planet Earth.

                          — photo Jochen Tack/Alamy

That idea doesn't surprise me at all. On the contrary. I can well imagine a randy Cro-Magnon gentleman running into a horny Neanderthal lady, on his way home from the hunt at the end of a wintry afternoon, and paraphrasing in his imagination the well-known Canada Dry words: "It looks like whisky, smells like whisky, and tastes like whisky."

I imagine myself in the Cro-Magnon's place, on the horns of a dilemma. Regardless of the respective species (or races, or whatever) of the Neanderthal wench and me, I would have surely decided, there and then, that a little bit of Guinness would be good for me... and for her, too, no doubt.

Now, I learn today from The Guardian [access] that certain sourpuss scientists are abandoning this delightful idea of intertribal rock 'n' roll. They suggest that the DNA stuff shared by Neanderthals and us humans was surely a remnant of code that existed already in our most recent common ancestor, half a million years ago, before we had differentiated into Neanderthals and humans. Their reasoning is perfectly plausible, but it strikes me as somewhat puritanical. I far prefer the friendly idea of a whole lotta prehistoric shakin' goin' on.

Friday, December 30, 2011

Baby mammoth

Last night on French TV, I watched a fascinating 95-minute documentary about the discovery in Siberia, in 2007, of an intact carcass of a baby woolly mammoth named Lyuba, who died at the age of a month or two—probably by drowning or being suffocated by mud— some 40,000 years ago.

The video I saw was a compilation of documentary fragments from several sources, but it tells the story of Lyuba in a complete and constantly interesting fashion. As far as I can tell, it was a French-language version of a product made by National Geographic whose title is Waking the Baby Mammoth. In any case, this afternoon, I was able to order a copy of the French version from Amazon.

Some viewers might be shocked by a cute gimmick of a Disney kind exploited haphazardly throughout the documentary. A highly-realistic virtual representation of little Lyuba is seen scampering around, from time to time, in the real world context of modern scientists who have been examining the unique carcass. Personally, I was never annoyed by these brilliantly-created excursions into fantasy, which seemed to reflect dreamlike visions that might indeed have been present in the minds of the scientists. At times, though, it was weird in the sense that the lovely little beast seemed to be invited along to participate in her own autopsy.

I appreciated greatly the performance of the US paleontologist Daniel Fisher of the University of Michigan, who appeared to have a deep philosophical empathy both with the scientific phenomenon of mammoths and with the traditions of the Nenets herders who survive today in the icy Arctic world that was once the lush domain of Lyuba and her kin.

Tuesday, February 1, 2011

Famous book for sale

The problem, if I don't manage to sell this book—which I bought out in Australia in 1961, shortly before leaving for Europe—is that I might end up tearing it apart in a fit of rage… which would be a pity, in a way. You see, I'm convinced that there are many people, out there in the wide world, who would love to own an old copy of the English translation of this celebrated essay by the French Jesuit priest Pierre Teilhard de Chardin. I myself, at the age of 20, was convinced a priori that this would surely be one of the greatest works of scientific literature I had ever met up with, because of the planetary reputation of this paleontologist who had attempted to blend together Darwin's theory of evolution and a belief in the existence of a divine creator. But then I made an attempt to actually read the book, and I was rather discouraged. In fact, huge sections of The Phenomenon of Man are no more than strings of words (including weird French neologisms such as hominisation) thrown together in an unexpected manner, forming heaps of unintelligible garbage. Interspersed with all this muck, there are small sections of technical stuff about various hominoid fossils, designed to trick you into imagining that the entire thing is a work of science. Appalling…

In France, during the first half of the 20th century, the prestige of Abbé Breuil [1877-1961] had accustomed people to imagining that a good dose of Catholic faith was a fine attribute for researchers in paleontology. Soon after meeting up with my future wife, I was intrigued to learn that Christine's maternal grandmother—an intelligent and artistic woman from Provence, whom I admired immensely—was a profound disciple of Teilhard de Chardin. But that merely proves something we knew already: that the Holy Spirit works in devious ways…

Today, with the Internet, Teilhard de Chardin would never have been able to get away with the production of such a mess. In any case, prospective readers would have learned already, in 1953, that Teilhard de Chardin had been one of the "experts" duped by the biggest science hoax ever: the discovery in England of the so-called Piltdown Man. Apparently the Jesuit priest had been tricked into believing that a filed-down canine tooth, found at the Piltdown site, was a genuine attribute of the creature. Today, not even a school student in biology, equipped with a microscope and a minimum of instruction, would be pardoned for making such a gigantic blunder. Incidentally, another alleged expert in paleontology who fell for the Piltdown hoax was my compatriot Grafton Elliot Smith, whom I presented recently in an article entitled Prehistoric encounters [display].

I've been rereading A Devil's Chaplain by Richard Dawkins, a collection of essays published in 2003.

One of his reviews celebrates the literary style of the British Nobel laureate in medicine Peter Medawar, who penned a vitriolic attack of the notorious book of Teilhard de Chardin. Medawar's short critique, which is brilliant stuff, can be downloaded from the web. Click the portrait to access it.

Getting back to Teilhard, a thing that annoys me greatly is the condescending way in which he set out to tell his readers what had happened "since the days of Darwin and Lamarck", as if these two men were to be grouped together, and then discarded as out-of-date. At another spot, he speaks of "the heroic times of Lamarck and Darwin". Today, on the contrary, the work of Darwin is more alive than ever. What is totally archaic, on the other hand, is the tasteless and indigestible soup of the Jesuit priest who once tried [if I may mix metaphors] to pull the paleontological wool over our eyes.

My copy of the book should not be particularly expensive. That will depend, of course, on the volume of demands.

Sunday, December 26, 2010

Prehistoric encounters

Well before my time, the high school in my native town of Grafton (New South Wales, Australia) was associated with two youths who went on to become world-renowned scholars in their respective domains.

In 1875, 18-year-old Havelock Ellis left his native London aboard a ship—captained by his father—bound for New South Wales. In spite of his lack of teaching credentials, he succeeded in convincing a grammar school in Grafton to hire him as a master. Soon after, the school's headmaster died, and Ellis inherited his job, which he managed to keep for a year... up until his incompetency became blatant.

Back in England, he studied medicine, and ended up becoming a world pioneer in a novel domain: sexology. I might point out that, during my time as a student in Grafton, I don't recall ever hearing of this illustrious gentleman. Retrospectively, I can understand why. In Grafton at the time I attended the high school, no teacher would have ever dared to utter a word such as "sexology". Ignorance was bliss, and the expression "carnal knowledge" designated a crime for which one of my friends (a young cyclist, accused of a brief encounter with a consenting under-age girl) got sent to jail. In another incident, a Grafton shopkeeper was imprisoned for practicing the kind of relationship that Havelock Ellis had analyzed in his first celebrated treatise: homosexuality.

As his given name suggests, Grafton Elliot Smith was born in my future native town in 1871, and he went to school there (where his English-born father was the headmaster) up until the age of 12. He studied medicine at the University of Sydney, and was a resident at the Royal Prince Alfred Hospital. He specialized in brain anatomy, and went on to become a distinguished professor of anatomy in the UK. In an unexpected career switch, he turned to prehistoric anthropology, and even wrote a book on the pharaoh Tutankhamun. Unfortunately, the eminent scholar made the mistake of being bamboozled by a "discovery" that turned out to be a notorious hoax.

That affair had a distinctly negative effect upon the reputation of Sir Grafton Elliot Smith. His so-called diffusionist theories on the spread of human culture had also finally gone out of fashion. Before his prestige paled, Smith had influenced a fellow-Australian scholar who would go on to make a gigantic discovery in paleontology.

Raymond Dart was born in Brisbane in 1893, and he studied medicine at the University of Sydney, where he was a resident of Saint Andrew's College. (I happened to spend 1956 at that college.) In much the same way as Grafton Elliot Smith, Raymond Dart started to get interested in paleontology. In 1924, he discovered an extraordinary skull of a three-year-old child at a place named Taung in South Africa. Around its human-like eye sockets, the skull bore beak marks, suggesting that the Taung Child had been devoured by an eagle. This upright-walking creature had lived 2.5 million years ago, but its brain was as small as that of a modern chimpanzee.

Raymond Dart decided that this creature—part simian, part human—deserved a new genus name. Unfortunately, he invented a clumsy term: Australopithecus, which means "southern ape-man". So, the official name of the Taung Child was Australopithecus africanus. Here's an artist's impression of what the distraught parents might have looked like, as they watched in terror their child being borne away on the wings of an eagle:

Trivial anecdote: When I started to work as an assistant English teacher at the Lycée Henri IV in Paris in 1963, I was intrigued to discover that all the students were familiar with the ugly French translation of this stupid generic term, Australopithèque, which sounds as if it has something to do with Australia. So, it was inevitable that I should receive this term, invented by my compatriot Raymond Dart, as a nickname. How's that for a ridiculous situation? It was hard for me to explain that we Australian citizens—already associated with the people that the French often refer to erroneously as "Arborigènes", since they imagine vaguely that the indigenous tribes of Australia once lived in trees (arbres in French)—had no direct links with so-called "southern ape-men" in Africa.

In fact, the research era during which paleontologists contemplated the forms of fossil fragments, while attempting to invent plausible generic and specific categories, has already drawn to a close. Today, the mtDNA (mitochondrial DNA) extracted from tiny prehistoric relics provides an amazingly precise means of interpreting mysterious paleontological findings. A splendid example of this new approach is provided by the case of the tooth found in the Siberian cave of Denisova.

Not so long ago, it would have been unthinkable to draw any profound conclusions from such an insignificant element. How can we even be certain that it is indeed a human tooth? Well, in fact, it isn't! Analysis of the mtDNA and comparisons with the human and Neanderthal genomes indicate that these so-called Denisovan creatures, who lived in Siberia some 30,000 years ago, were in fact closer to Neanderthals than to the Homo sapiens species.

Both the Neanderthals and the Denisovans had a common ancestor (shown in red) located on a branch that was parallel to that of our human ancestry. But the most extraordinary finding was that these Denisovans (whose known relics were found up in Siberia) apparently did some casual rocking and rolling with the ancestors of present-day Melanesians, in the Antipodes.

God only knows where they held their parties, because it's a long way from Siberia to these Pacific islands to the north-east of Australia. We can be fairly certain, however, that future DNA finds will reveal the addresses of such encounters between humans and Denisovans, no doubt somewhere in Asia.

Monday, August 2, 2010

Much older than we had imagined

Several Australians have become notorious for their Creationist beliefs. First and foremost, of course, there's the Queenslander Ken Ham, who went to the USA and founded a museum with exhibits that show our ancestors frolicking around with dinosaurs.

If you're a bit masochistic, and you would like to hear the voice of the Holy Ham in an auto-tuning context, then click here. Clearly, if this guy gets any loonier, he'll end up getting put away… or maybe elected by Creationist supporters as Aussie of the Year.

Another remarkably dumb Aussie is now well-known on the web. In March, when Richard Dawkins was out in Australia for the Atheist Convention, he found himself seated alongside a senator, Steve Fielding, whose utterances revealed that he was a so-called "young-Earth Creationist". That's to say, this elected pollie really believes that our planet was created less than 10,000 years ago. The amusing encounter of Dawkins and Fielding can be seen in the following video:

Apparently Dawkins said jokingly, later on, that the intelligence of Steve Fielding was surely akin to that of an earthworm…

Yesterday, a delightful anecdote was aired on the Pharyngula blog of PZ Myers in an article entitled Australians are learning what it means to have creationists in the classroom [display]. During a scripture lesson in a Queensland school, when the religious instructor evoked Adam and Eve as the ancestors of all humans, a student complained that such a narrow stock of original DNA would have led to catastrophic inbreeding. The instructor replied that, at the time of Adam and Eve, "DNA wasn't yet invented". Hilarious commentators were quick to point out the magical power of this kind of argument. One might imagine that all kinds of marvelous things took place, for example, before the "invention" of the laws of science, or even the "invention" of good old common sense!

At the same time that these specimens of brainless tripe are giving us a laugh, amazing progress is being made in the dating of animal life on Earth. The following photo shows us a small fossil that was found recently in Gabon by a French geologist, Abderrazak El Albani, attached to the university of Poitiers.

For many years, paleontologists have considered that the first multicellular animals of this kind appeared in the ocean some 600 million years ago. Well, that date will have to be readjusted greatly, because the above fossil was found in a rocky site whose age is 2.1 billion years!

Yesterday, French people were thrilled to learn that the fine city of Albi in south-west France—where the medieval Christian sect of Catharism came into being—has just become a Unesco world-heritage site.

The geologist El Albani, who has found that multicellular life is 1.5 billion years older than what we had previously thought, is intent upon getting the home of his fossil in Gabon honored as a Unesco world-heritage site. I find that a splendid idea, in the sense that it emphasizes the fact that scientific knowledge is a basic part of our cultural heritage.