Posts Tagged ‘Human’

Piltdown Man

December 19, 2016

The intellectual process of developing theories and hypotheses based on observations and experiments and checking those hypotheses with further experiments and observations that we refer to as science has proven itself to be the best tool human beings have ever developed for understanding and making use of the world around us. This process is not an easy one, however.  Not only is it a lot of work to conduct the necessary experiments and interpret the results, but the process demands a  rigorous honesty that does not come easily to anyone. Most people are less interested in discovering the truth than in being proven right, and there is always a tendency to consider only the evidence that confirms existing ideas and ignore the evidence against them. As Dr. Richard Feynmann put it in his lecture about cargo cult science:

It’s a kind of scientific integrity, a principle of scientific thought that corresponds to a kind of utter honesty—a kind of leaning over backwards.  For example, if you’re doing an experiment, you should report everything that you think might make it invalid—not only what you think is right about it: other causes that could possibly explain your results; and things you thought of that you’ve eliminated by some other experiment, and how they worked—to make sure the other fellow can tell they have been eliminated.

Details that could throw doubt on your interpretation must be given, if you know them.  You must do the best you can—if you know anything at all wrong, or possibly wrong—to explain it.  If you make a theory, for example, and advertise it, or put it out, then you must also put down all the facts that disagree with it, as well as those that agree with it.  There is also a more subtle problem.  When you have put a lot of ideas together to make an elaborate theory, you want to make sure, when explaining what it fits, that those things it fits are not just the things that gave you the idea for the theory; but that the finished theory makes something else come out right, in addition.

In summary, the idea is to try to give all of the information to help others to judge the value of your contribution; not just the information that leads to judgment in one particular direction or another.

The problem is that this level of integrity is almost contrary to human nature. There is a great temptation to cheat, particularly when the rewards of fame and fortune are present.

One of the most famous instances of scientific cheating is Piltdown Man. Piltdown Man was a hypothetical “missing link” between human and ape discovered by an amatuer paleontologist Charles Dawson at the Piltdown gravel quarry in 1912. Dawson stated that workmen at the quarry had discovered skull fragments which they had given to him. Dawson had been able to reconstruct the skull with these fragments and other pieces that he had found at Piltdown. The resulting skull had a roughly human cranium, although only two thirds the size of a modern human brain, but an ape-like jaw with large canines. Clearly this was the remains of a creature caught midway in the transition between human and ape, the missing link of the chain of evolution.

Charles Dawson

Charles Dawson

At first, there was some skepticism about Dawson’s find. The canines seemed too large for the jaw and the whole thing seemed to be just a little too neat a combination of human and ape. Then, Dawson found another skull about two miles away. It might be possible for a human skull and ape jaw to have somehow been put together once and fossilized . Surely that couldn’t happen twice. Piltdown Man was accepted as a legitimate ancestor to homo sapiens.

 

Piltdown Man

Piltdown Man

 

At the time of Piltdown Man’s discovery, relatively little was known about the details of how humans evolved from their apelike ancestors. Over the years, more early human fossils were discovered and much more was learned about how humans became human. As the missing pieces were fitted together, it became increasingly obvious that Piltdown Man didn’t fit in. Paleontologists began to suspect that Piltdown Man was either an aberration, perhaps a mutation of some sort, of a hoax. In 1953, the question was definitely settled. Piltdown was shown to be a hoax. Piltdown Man was actually a rather crude forgery. The skull was that of a medieval man with a small head. The jaw was from an orangutan and the canines were the teeth of a chimpanzee.

The only remaining question was whether Charles Dawson was the forger or whether he was merely an innocent dupe. Dawson was the obvious suspect, but there were others associated with the discovery of Piltdown Man, who might have been able to perpetrate such a hoax, notably Sir Arthur Conan Doyle of Sherlock Holmes fame, and the Jesuit priest and paleontologist Pierre Teilhard de Chardin. Recent research, however, has indicated that Charles Dawson was indeed the forger. He actually had something of a history of perpetrating such hoaxes and was well known for his skill at making unexpected archaeological finds, invariably later discovered to be forgeries.

Why did it take so long to expose Piltdown Man? The forgery was not very sophisticated and the discoverer had a reputation for not being particularly honest. To be fair, a space of forty years between the discovery and the exposure is not an unreasonable amount of time considering how much was discovered about human development in that time. Still, one might have expected more skepticism to be shown, especially considering how important the find seemed to be at the time. It seems as if everyone involved in the research involving Piltdown Man showed a disregard for the sort of scientific integrity that Dr. Feynman was talking about. For years no one seemed to want to consider the increasing evidence that Piltdown Man wasn’t real.

I think that was the problem. Piltdown Man was exactly what most paleontologists were expecting. At the time of his discovery, the general consensus was that human beings developed large brains first, while retaining a more apelike physiology such as a large jaw and lack of bipedalism. Only later, they believed did humans began to walk erect and to develop a flatter, more human face. It was also generally believed that human beings developed somewhere in Eurasia, Perhaps even in Germany, where Neanderthal Man had been discovered not long before, or in England. There was a certain amount of nationalistic pride in being the area where humanity began. It is not that surprising, then, that British paleontologists were the least likely to be skeptical about Piltdown Man.

In any event, these assumptions that Piltdown Man seemed to confirm have proven to be wrong. Primitive humans, such as the Australopithecus (Lucy)  began to walk erect on two feet long before developing larger brains, and the human race arose in Africa, almost the opposite of what was generally believed. I wonder how much these widely held but wrong assumptions held back the science of paleontology.

I also wonder how many other Piltdown Mans there are out there that are holding back the progress of science. I don’t mean hoaxes or forgeries necessarily, though that is a greater problem is science than many realized, but ideas and theories that are held to be settled science but aren’t. I wonder how much that everyone “knows” to be true and so not worth questioning, are not true, and how long it will take before anyone thinks to question it.

How to Think Like a Neandertal

December 22, 2013

Neandertal men, or Neandertals have intrigued people since the discovery of the first fossil remains were discovered in the Meander Valley back in 1856. Early ideas about Neandertals were heavily influenced by preconceptions about human ancestry current at that time and so Neandertals were believed to be the missing link between human and ape and so Neandertals were depicted as bestial, sub-human primitives. More recent research has revealed that Neandertal Man or Homo neanderthalensis was very closely related to modern Homo sapiens, perhaps even a subspecies of sapiens. More recent depictions of Neanderthals have tended to be more sympathetic, including Jean M. Auel’s Clan of the Cave Bear and the Geico cavemen.

Paleontological research and the sequencing of Neanderthal DNA have taught us a lot about their appearance and habits, but not so much, what they were really like. How “human” were the Neanderthals? Were as intelligent as modern humans, or more, or less? Would they fit into modern society?

Thomas Wynn and Frederick L. Coolidge attempt to answer these questions in their book, How to Think Like a Neandertal. Wynn, an archaeologist and Coolidge, a psychologist, go over the available evidence to try to reconstruct how Neanderthals really thought. This exercise necessarily requires a lot of speculation since there are no living Neanderthals to examine, but most of their guesses seem to be sound, based on the evidence they present.

how-to-think-like-a-neandertal-thumb-300x455-171911

Wynn and Coolidge believe that Neanderthals were as intelligent as modern humans were. Judging from the artifacts they left, they were certainly not stupid. Yet, their intelligence seems to be subtly different from ours. Neanderthals did not innovate much. Their tools are much the same in design throughout their range. The tools were well made, but they lacked the sort of regional variations that are characteristic of tribes of modern humans who live far apart. The tools retain the same designs for tens of thousands of years, while the tools of even the most primitive modern humans show some development over time. Wynn and Coolidge speculate that Neandertals were very conservative in temperament and did not like the new or unexpected.

Neadertals were very strong compared to modern humans and lived hard and dangerous lives. Wynn and Coolidge assert that emotionally, Neanderthals were stoic and used to dangers and injuries. They took care of injured members of their communities. These communities or bands were rather small, perhaps no more than a dozen or two dozen individuals. Neadertals did not travel much and did not interact with other bands except on rare occasions. They do not seem to have engaged in any sort of trade between bands. Because of this, Neadertals were probably suspicious of strangers and less sophisticated in social interactions than modern humans who lived in larger communities that interacted with one another.

Neadertals almost certainly had language. They had the same genes that in humans control the acquisition and use of language. There is no way now to know what their languages were like and how they compare to the languages of our time. Wynn and Coolidge believe that their language must have been different from any language used by Homo sapiens, perhaps more context specific and with more use of stock phrases as part of their conservatism. Their humor might also have been different, more physical and maybe far less use of word play. I think, though, that this subject is the one in which their speculations are less well based on available evidence. I believe that unless a Neadertal is resurrected using “Jurassic Park” technology, we simply do not have enough evidence on which to base any speculations.

How to Think Like a Neandertal is an interesting book about an interesting people. I only wish it were possible to know more about the Neandertals.

 

No Man is an Island

August 20, 2012

As the poet John Donne put it,

No man is an island entire of itself; every man is a piece of the continent, a part of the main; if a clod be washed away by the sea, Europe is the less, as well as if a promontory were, as well as any manner of thy friends or of thine own were; any man’s death diminishes me, because I am involved in mankind. And therefore never send to know for whom the bell tolls; it tolls for thee.

Though he had it slightly wrong. If the latest research in biology is any indication, we are, each one of us, a continent, perhaps even a world in ourselves. That is the impression I got when I read this article in The Economist.

The traditional view is that a human body is a collection of 10 trillion cells which are themselves the products of 23,000 genes. If the revolutionaries are correct, these numbers radically underestimate the truth. For in the nooks and crannies of every human being, and especially in his or her guts, dwells the microbiome: 100 trillion bacteria of several hundred species bearing 3m non-human genes. The biological Robespierres believe these should count, too; that humans are not single organisms, but superorganisms made up of lots of smaller organisms working together.

It might sound perverse to claim bacterial cells and genes as part of the body, but the revolutionary case is a good one. For the bugs are neither parasites nor passengers. They are, rather, fully paid-up members of a community of which the human “host” is but a single (if dominating) member. This view is increasingly popular: the world’s leading scientific journals, Nature and Science, have both reviewed it extensively in recent months. It is also important: it will help the science and practice of medicine

The microbiome does many jobs in exchange for the raw materials and shelter its host provides. One is to feed people more than 10% of their daily calories. These are derived from plant carbohydrates that human enzymes are unable to break down. And not just plant carbohydrates. Mother’s milk contains carbohydrates called glycans which human enzymes cannot digest, but bacterial ones can.

This alone shows how closely host and microbiome have co-evolved over the years. But digestion is not the only nutritional service provided. The microbiome also makes vitamins, notably B2, B12 and folic acid. It is, moreover, capable of adjusting its output to its host’s needs and diet. The microbiomes of babies make more folic acid than do those of adults. And microbiomes in vitamin-hungry places like Malawi and rural Venezuela turn out more of these chemicals than do those in the guts of North Americans.

The microbiome also maintains the host’s health by keeping hostile interlopers at bay. An alien bug that causes diarrhoea, for instance, is as much an enemy of the microbiome as of the host. Both have an interest in zapping it. And both contribute to the task. Host and microbiome, then, are allies. But there is more to it than that. For the latest research shows their physiologies are linked in ways which make the idea of a human superorganism more than just a rhetorical flourish.

So, each one of us is not just a single entity, but a whole community of microbes. I’ll never feel lonely again. Meanwhile, we should all be good to our bacteria, they are our closest friends.


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