Yearly Archives: 2007

Charles Darwin Bicentennial – Iguanas, a “most disgusting, clumsy lizard…

…They are as black as the porous rocks over which they crawl & seek their prey as from the Sea. — Somebody calls them “imps of darkness”. — They assuredly well become the land they inhabit. — When on shore I proceeded to botanize & obtained 10 different flowers; but such insignificant, ugly little flowers, as would better become an Arctic, than a Tropical country. — The birds are Strangers to Man & think us him as innocent as their countrymen the huge Tortoises. Little birds within 3 & four feet, quietly hopped about the Bushes & were not frightened by stones being thrown at them.” [Darwin’s Beagle Diary (1831-1836)].

And thus we get a hint of Darwin’s impressions of the Galapagos, and in particular, that Island’s marine iguanas.

The Iguana family is Iguanidae, but most Iguana’s you’ve cuddled in the pet store are members of the genus Iguana (and most likely species Iguana iguana.) The Galapagos Islands have two or three species of iguana: The Land Iguana is Conolophus subcristatus and Conolophus pallidus, or perhaps is actually the subspecies Conolophus subcristatus pallidus. The marine iguana is Amblyrhynchus cristatus.

The two genera of iguana on the Galapagos seem able to interbreed, though they otherwise also seem to make good, distinctive species. (No, it is not really true that inability to inbreed is “THE biological definition of species….” it is more complex than that. A topic for another time, perhaps.) The phylogenetic relationship among the Galapagos iguanas and continental iguanas is similar to that among the finches and other Galapagos animals… complex and more complex because of the apparent fact that while the oldest of the Galapagos islands is about four million years old, earlier islands, perhaps going back twice that age, formerly existed but are now eroded down below sea level. One wonders what will happen next ice age (or what happened last ice age) when a 120 -150 meter drop in sea level exposes some of these islands! The point is that these volcanic islands have a complex history, and it is likely that the islands themselves have a complex relationship to the distant continent. Again, the topic of another post perhaps.

The following passages from Darwin (1839) Continue reading Charles Darwin Bicentennial – Iguanas, a “most disgusting, clumsy lizard…

Charles Darwin Bicentennial – Notebooks

Darwin published hundreds of pages of text, but he also kept notebooks many of which come down to us today. They can be roughly divided into two aspects, the Beagle field notebooks of 1831 – 1836, and his later notes. Sometimes these notes are found in a single book, and one way they are told apart (when otherwise undated) is by the orientation of the notes themselves. Darwin wrote “portrait” style in the field, but “landscape” style in the lab.

Many of the notebooks are preserved at Down House, Darwin’s residence. Down House has 14 Beagle notebooks, one crossover, and one post-voyage notebook, as well as a fragmentary notebook which is believed to contain post-voyage notes.

The complete transcription of all but one of the Down House Notebooks is available on The Complete Works of Charles Darwin Online. The exceptions are previously published books, for which the publication is available at the same web site.

It is in these notebooks (as well as letters) that one can get a glimpse of Darwin’s thinking about evolution and the evolution of his thinking. Continue reading Charles Darwin Bicentennial – Notebooks

Charles Darwin Bicentennial – Gauchos

Painting of a Gaucho
Click to visit Obkouna Art Works

You may have noticed that these posts on Darwin are (so far) in alphabetical order. So this means, if I’m doing Gauchos, I must not be doing Fuegians. Maybe I’m saving Fuegians for 2009!?

But I will mention them. The Fuegians live in Tierra del Fuego (no surprise there) way down at the southern tip of South America. Most people know that, but did you also know that when the Beagle departed Portsmouth Harbor in 1831, it was carrying three Fuegians previously captured by Fitzroy and brought to England?

The Gauchos are the cowboys of the so-called Southern Cone and Pampas. The Gauchos are a Latin American version the horse mounted pastoralists that emerged wherever four things are found together: Grasslands, horses, people and cattle. Like all horse-mounted pastoralists, they have been known to have certain cultural tendencies or traits. These include being incredibly good horse riders. It includes a disdain for any sort of locomotion that does not involve a horse. The Gauchos are held in high esteem as a symbol of trustworthiness and strength, this symbol commonly exploited in regional politics in Argentina and Brazil, or by sports teams (in a mascot-like fashion), even in North America.

The Gauchos are beings with four hooved-legs and two heads because a Gaucho is nothing without his horse. Most wars in the region required Gaucho calvary.

Darwin spent a fair amount of time among the Gauchos, and both Darwin and Fitzroy Continue reading Charles Darwin Bicentennial – Gauchos

Charles Darwin Bicentennial – Finches

Darwin’s finches are a classic and historically important example of a species radiation (sometimes called an “adaptive” radiation, but that implies a specific assertion about the cause of the radiation which may not be appropriate in all cases). During the five weeks that Darwin spent on the Galapagos in September, 1835, he made a number of observations of these birds, but they did not occupy his time or attention more than any other aspect of this remarkable archipelago of islands. It seems that Darwin did not recognize all of the finches as finches, thinking some were of an entirely different group of birds, and in some cases, the variety seen across some of 13 or so species was initially interpreted by Darwin to represent a notably large range of variation in a single species. Please remember, Darwin was a rock man more than he was a bird man, at the time.

John Gould was a bird man, the most famous of his time at least in England, and he is the one who re-identified specimens mistaken by Darwin to be three or four different kinds (blackbirds, grosbeaks, and finches) as representing about a dozen different finches that had diversified into distinctly different forms.

There is even a Vampire Finch. And, even more amazingly, there is a Vampire Finch Movie!(click here to find out more…)

There are two separate dimensions to variation in these finches. The overarching pattern is that different species are found on different islands, owing to a combination of genetic drift and local adaptation, the other is that different finches living in overlapping geographical ranges had different adaptations for differing diets. One gets the impression that Darwin was struck more by this first aspect of variation than the second. This pattern of variation … island by island … also applied to other animals such as the tortoises.

The phrase “Darwin’s Finches” was first advanced, or at least popularized, by David Lack, the famous ornithologist who also advanced a version of group selection theory, in the 1940s.

Here is a list of the species cribbed from Wikipedia: Continue reading Charles Darwin Bicentennial – Finches

Charles Darwin Bicentennial – Coral Reefs

As Europeans plied the seas in search (and ultimately management) of colonies and conquests, they learned the practical geology they needed to find their way and avoid wrecks. Everyone knows that Charles Darwin’s opportunity to spend several years on the Beagle ultimately rested on the British Admiralty’s need to improve navigation maps, especially along the South American coasts. The near shore conditions change, some of the existing maps were not adequate, and the size of ships was increasing so once-safe passages no longer necessarily were. The Beagle’s Captain Fitzroy had a reputation was for tenacious accuracy in map making and navigation, and the fact that a one or two year voyage (as planned) more than doubled in its time is a testament to this.

One of the features critical to navigation is the coral reef. Reefs provided an excellent way to wreck your ship in a storm as well as one of the best ways to Continue reading Charles Darwin Bicentennial – Coral Reefs

Charles Darwin Bicentennial- Beagle and The Voyage


The point of the voyage of the Beagle was to make an accurate survey of the coastal areas of South America, and to run a chain of chronometric readings around the world. The making of geological maps of all of the regions visited was also on the “to do” list for this expedition. Darwin was well matched for this job, because his main interest and to a large degree his primary training was geology. All this stuff about Evolution and Natural Selection was to come later. Darwin knew he would be making extensive collections of biological materials and prepared for this by seeking advice from his mentors on the methods of preservation and shipping of preserved plants and animals, and he was keenly interested in observing the natural world during his entire trip. I don’t mean to suggest otherwise. But nonetheless it is true that geology was both his focus and his job on the voyage. Of the twenty four notebooks we know about of Darwin’s, from this voyage, most of the written material is about geological observations.

The story of Darwin’s invitation to join Captain Fitzroy on the Beagle is a long, complicated, and fascinating one. You can read about it in Darwin’s Autobiography, and several scholarly works, as well as various fictionalized accounts. For example, there were issues with his father: Continue reading Charles Darwin Bicentennial- Beagle and The Voyage

Charles Darwin Bicentennial – A Tangled Bank

Last Darwin Post I gave you the famous “Tangled Bank” quote, in which Darwin links the concept of selection to the concept of ecology and thus derives “grandeur in this view of life.”

This is a theme of much of Darwin’s writing in The Origin, and in fact, the Phrase “Tangled Bank” shows up much earlier in the volume.

In the case of every species, many different checks, acting at different periods of life, and during different seasons or years, probably come into play; some one check or some few being generally the most potent, but all concur in determining the average number or even the existence of the species. In some cases it can be shown that widely-different checks act on the same species in different districts. When we look at the plants and bushes clothing an entangled bank, we are tempted to attribute their proportional numbers and kinds to what we call chance. But how false a view is this! Every one has heard that when an American forest is cut down, a very different vegetation springs up; but it has been observed that ancient Indian ruins in the Southern United States, which must formerly have been cleared of trees, now display the same beautiful diversity and proportion of kinds as in the surrounding virgin forest. What a struggle must have gone on during long centuries between the several kinds of trees, each annually scattering its seeds by the thousand; what war between insect and insect—between insects, snails, and other animals with birds and beasts of prey—all striving to increase, all feeding on each other, or on the trees, their seeds and seedlings, or on the other plants which first clothed the ground and thus checked the growth of the trees! Throw up a handful of feathers, and all must fall to the ground according to definite laws; but how simple is the problem where each shall fall compared to that of the action and reaction of the innumerable plants and animals which have determined, in the course of centuries, the proportional numbers and kinds of trees now growing on the old Indian ruins!

(Darwin, C. R. 1869. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 5th edition. Pages 86-87)

This is a fantastic example of Darwin’s breadth of interest and integrated mind. He makes explicit reference to the fact that selection is context dependant (“widely-different checks act on the same species in different districts”). He is explicit about the fact that chance is NOT the operative force in organizing nature (a fact that creationists seem to ignore when they speak of the unlikelihood of a tornado passing through a junkyard creating a Boeing 747 and http://gregladen.com/wordpress/?p=264such hogwash). Continue reading Charles Darwin Bicentennial – A Tangled Bank

Parasitic Birds and The Red Queen Effect

The Avian Brood Parasites

The Avian Brood Parasites

Brood parasitic birds lay their eggs in the nests of other birds (the “hosts”) who then raise them as their own. Examples of parasitic birds includes the cuckoo, cow birds, widow (“whyda”) birds, honeyguides, and even the South American Black-headed Ducks. Brood parasitism is virtually a world wide phenomenon.

Many interspecific brood parasites are obligate for this strategy … this is the only way they raise their own young. There are many variants (beyond the scope of this post). Intraspecific parasitism is known in many colonially nesting birds.

The Red Queen effect is a concept now widely known by aficionados of biology. The phrase is from Alice Through the Looking Glass, but the biological concept was first developed by Leigh Van Valen, a biologist at the University of Chicago.

While the Red queen and Alice are discussing chess, the following dialog and events ensue: Continue reading Parasitic Birds and The Red Queen Effect

Global Warming. Julia has the Last Word

“The 2nd of February in Paris will be remembered as the day that the question mark was removed from the idea that humans had anything to do with climate change,” says Achim Steiner, quoted here.

It is not really true. Groups of scientists have been saying this for quite some time. I wonder what George Bush will say next?

But even before this scientific panel’s report was finished, last night (I’ll post a picture later), my daughter, Julia presented her “Achievement Fair” ( = science fair) project on Global Warming and it’s effects in the polar region, entitled “Global Warming … breaking the ice.”

To my knowledge it was the first Achievement Fair entry at her school that explicitly called for the impeachment of the President of the United States … under the list of “Things to do” (along with other items such as use compact fluorescent bulbs, car pool, etc.). Continue reading Global Warming. Julia has the Last Word

Models of Sexual Selection

Darwin was puzzled by exaggerated traits. (Aren’t we all, really?) For example, why would a widow bird male have a tail so long that he could scarcely fly away from predators? Indeed, speaking of birds:

What a contrast is presented between the sexes by the polygamous peacock or pheasant, and the monogamous guinea-fowl or partridge! Many similar cases could be given, as in the grouse tribe, in which the males of the polygamous capercailzie and black-cock differ greatly from the females; whilst the sexes of the monogamous red grouse and ptarmigan differ very little. Amongst the Cursores, no great number of species offer strongly – marked sexual differences, except the bustards, and the great bustard (Otis tarda), is said to be polygamous. With the Grallatores, extremely few species differ sexually, but the ruff (Machetes pugnax) affords a strong exception, and this species is believed by Montagu to be a polygamist. Hence it appears that with birds there often exists a close relation between polygamy and the development of strongly-marked sexual differences. On asking Mr. Bartlett, at the Zoological Gardens, who has had such large experience with birds, whether the male tragopan (one of the Gallinaceæ) was polygamous, I was struck by his answering, “I do not know, but should think so from his splendid colours.”

Darwin, C. R. 1871. The descent of man, and selection in relation to sex. London: John Murray. Volume. 1. 1st edition. Pages 269-270

I don’t want to give a comprehensive (or bullet proof) “definition” of sexual selection. Instead, I want to lay out a few key ideas and suggest a way to think of models of sexual selection.

Darwinian Sexual Selection.
Females possess a built in aesthetic Continue reading Models of Sexual Selection

911 Reverberates in Boston

Aqua Teen Hunger
Force. They may be
scary looking but
they are cartoons, not
terrorists.

On September 11th, 2001, George Bush made one of the most significant and critical errors of his presidency.

Personally, I think George Bush is a total boob, and he has made many mistakes and we will all be paying for some of them for years to come. This particular mistake, though, is one that a lot of other people in the Office of the Presidency may have made, so I don’t want to lean too hard on Ol’ George for this one. But it was a mistake. Here is what happened.

A well trained and well funded group of nineteen criminals hijacked four airplanes. They flew three of them into buildings and a fourth into a cornfield in Pennsylvania, having been thwarted by an impromptu attack by the passengers on the plane (they had planned it seems to fly that plane into a public building in Washington D.C.). Thousands died.

The mistake that Bush made in concert with his advisors was to ground all nonemergency civilian aircraft for a number of days. This had immediate and long term economic effects and Continue reading 911 Reverberates in Boston

An Evolutionary View of Humans 5: The Opposite Sex

Efe people
Ituri Forest
Anthrophoto is an
excellent source for
anthropology stock
photos

There have been many studies of what impresses us about members of the opposite sex, but to my knowledge these studies are largely centered on Western societies, and never of foragers. There has been consideration of this issue, but no large scale surveys. One of the reasons for this is that you can’t do large scale surveys in so-called “small scale” societies, because there are just not enough people.

But I can provide a few insights on what might be impressive to the ladies (things about men) in forager societies. Keep in mind, however, that this is strictly speculation, though informed speculation.

I had previously talked about sharing, and here I’d like to expand on one aspect of sharing, the so called “distribution and redistribution system,” and it’s meaning in relation to courting.

There is a pattern that has been observed in virtually all forager groups, whereby men divide up the spoils of the hunt in a certain, largely ritualized, way, then pass these packages of meat over to the women, who then redistribute the meat in a manner commensurate with the needs of members of the group. I’d like to describe how this works specifically with the Efe Pygmies as an exemplar for foragers in general. Many aspects of what I’m describing here are nearly universal among foragers. Moreover, I’m going to specifically talk about “group hunting” when several men are involved in one cooperative hunting episode. However, the principles involved here actually apply to other forms of hunting as well, to varying degrees.

The most common Efe group hunt is called “mota.” In this method of hunting, a number of men spread out in the forest to surround an area, with one man (the “beater”) going to the center of this area with one or more dogs. The dogs are released by the beater, sent out into this area and called back again and again. Game that is roused by the dogs are then subject to being shot at with arrows by the archers who had previously spread out. If an animal is hit, help from other hunters or from the dogs may be solicited, and the animal run to ground and dispatched.

The animals are usually carried back to near the camp (these animals are small and can be carried whole by one person) where two people (not the hunter himself) butcher the animal. The animal is cut into standard pieces: The head, each front limb and body quarter, each hind limb and body quarter, and an area of the middle of the animal including the last few ribs (this is considered to be the “special” part, possibly because it contains the backstrap/loin meat).

Sometimes the head is left with one of the forelimbs. Sometimes the back two quarters are kept together.

Each of these parts is then given to a different man depending on a set of rules that specify a link between a man’s role in obtaining this meat and a particular body part. The rules vary from place to place and presumably time to time in Pygmydom, but it may be, for instance, that the man who called and organized the hunt, usually the beater, gets the front left limb, the guy who trained/owned the dog that ran down the animal a back quarter, etc. The only really consistent thing across the different rule sets is that there is usually a key hunter (the person who first shot the animal, for instance) who gets this middle back piece.

One striking aspect of this is that efforts are made and culturally determined to ensure that a lot of people were involved in the kill of any animal, even by a lone hunter. Here are some of the rules that ensure this:

1) No man carries his own arrows. The metal tipped arrows the Pygmies use for hunting ground animals are each made by someone else. Therefore, if you shoot an animal, another man besides yourself was “involved.”

2) The dog is owned by a particular person.

3) A ritual fire is burned before the hunt by a particular person.

4) The beater is a particular person. These three — dog owner, fire burner, and beater, may be the same person, two people, or three people.

5) The animal is supposed to be butchered by individuals other than the prime hunter.

6) The animal is supposed to be butchered OUTSIDE OF CAMP (even it it runs into camp and dies there … it would be dragged outside of the camp for butchery) by TWO people. (Not one, even though that would be possible.)

7) Oh, then there is the guy who shot the animal!

All of this ensures that even if you hunt alone, multiple people will be involved.

Now, we are guessing that the ladies are concerned with the hunting, and the meat, and thus with the quality of hunters, in some way. So the first approximation is that the women measure the hunting ability of the men and take this into account during courtship. Previous studies have not supported this idea.

One idea that may work is that the ladies pay attention to the man’s package. What I mean by this, is they notice what package of meat he comes in to the camp with, which would give the woman an idea of his role in the hunt, and thus information to assess his hunting ability.

However, there is a catch to this: I have observed that the men hardly ever walk into camp with the pieces of meat that actually represents what they actually did for the hunt. If this is a signal, the men are being dishonest.

One idea that may work to get past this problem is that the men are being dishonest but the women can’t figure this out. If the men came into camp and verbally claimed a certain role in the hunt, the women (and others) could easily detect the lie. But by simply carrying this package of meat into camp and not saying anything, and handing this meat over to a particular woman (someone they are trying to impress) they are not as easily caught in the lie.

However, I don’t believe this for a second. I think the women would still be able to tell who is being honest, or at the very least, the women would understand that the whole exercise is a charade, and simply not use this as information in choosing a mate.

So this brings us to one more idea that may help understand this, and I think the explanation for what is going on.

Suppose a young man is a typical hunter, and is courting a prospective mate who is hanging around in camp (visiting her sister, perhaps). As a typical hunter, there really is not much he can do to increase his role in the hunt, other than simply showing up and doing his job. Most of the hunters are excellent shots, and although older guys do better than younger guys, how you do over a series of a few hunts is also very largely a matter of luck.

But suppose this young guy comes into camp each day for two or three days in a row with a real nice package, something that would indicate an important role in the hunt. But he did not earn this package by what he did during the hunt. Instead, his male relatives and friends give him the package, knowing that he’s interested in the woman likely to be in camp on their return.

This indicates nothing about his hunting ability to the woman. But it does indicate something much more important: It indicates that he is not a complete jerk. It indicates that he has friends, that they will give him a break, and that he is part of a coalition of cooperative foragers. That is what makes a good mate.

Indeed, if women made choices among men based hunting ability, then they would be making poor choices. First, hunting ability might be important, but many other things are important as well. Second, as noted above, most forager men are pretty good at hunting. How well someone does is more a matter of luck than ability. So, hunting is not a trait that varies meaningfully or that can be assessed accurately.

Having said that, among the Efe, there is a form of hunting that is done by only some men, and that produces on its own about the same amount of meat as all the other hunting efforts combined, on an annual basis. This is the killing of an elephant. It is hard to do, far more dangerous than other forms of hunting, and highly productive. I suspect a lot of women would not be interested in such a mate. The guy must be crazy, after all. But some are. It is very rare to find Efe men with more than one wife (it is allowed but very uncommon). An Efe man does not usually have more than one wife, but when he does, it is often because he is an elephant hunter.

An Evolutionary View of Humans 1: Introduction
An Evolutionary View of Humans 2: Sleep
An Evolutionary View of Humans 3: Remembering Names
An Evolutionary View of Humans 4: Sharing
An Evolutionary View of Humans 5: The Opposite Sex

An Evolutionary View of Humans 4: Sharing

Efe people
Ituri Forest
Anthrophoto is an
excellent source for
anthropology stock
photos

One of the biggest differences between our nearest living relatives (The common chimpanzee, Pan troglodytes) and humans is our unique sense of the importance of a social contract. We have a concept of ownership, possession, exclusivity of access, etc. when it comes to material goods such as tools or resources, and of course, sexual relationships. It has been argued that this is a feature that can be found in primates. In a classic series of experiments done by Kummer with baboons, he showed that one male baboon perceived an ongoing sexual liaison between another male and a particular female. As long as the paired male was in sight, the focal baboon would not make sexual advances towards the paired female even though she was in a state of sexual receptivity. This was the case even when the focal male and the paired female were enclosed in a cage together, with the paired female enclosed in a different cage a safe distance away. Similar observations have been made in other primates including chimpanzees in captivity and in the wild.

However the presence of a vague ability to perceive danger — that you will likely be severely attacked by a large male under certain circumstances — is expected in social primates. What Kummer’s experiment may really demonstrate is that baboons don’t “get” cages.

The evolution of a sophisticated mechanism or set of mechanisms in hominids (humans and their upright ancestors) that elaborates on this capacity is what we would expect from an evolutionary perspective. We are upright using our hind limbs mainly for locomotion, and thus different from other apes, but at the same time the nature of our uprightedness (that we can also use overhead bars and straps on a bus or subway for stability, for instance) is a feature of our positional behavior that relates directly to the fact that apes tend to suspend below branches rather than walk atop them (as to Old World monkeys).

In other words, I don’t think that a trait observed in one species is not unique and not the result of adaptive evolution just because a mild form of the trait is observed in other closely related form. Such a situation — total uniqueness — is simply not expected most of the time.

Tropical and subtropical human forager groups all exhibit what we call a “sharing ethic.” Typically, this is manifest as social rules whereby if one person asks another for a particular thing, it is simply given. Both stinginess and gloating (over possession of something) are culturally proscribed. A person is judged by others on the basis of many things, but near the top of the list is a strong sharing ethic. It is even likely that people show off by trying to be the better sharer, and in some cases, the better not-shower-offer.

From a biological perspective it is thought that sharing is necessary in foraging societies because the nature of foraging is such that no one individual can maintain a sufficiently consistent food supply over medium to long term on the basis of their own efforts. Only by division of labor (often by sex) and sharing, whereby one person with a surplus distributes that surplus one day, and in return benefits from the largess of others on other days, can an individual avoid periods of starvation that would sometimes last days or weeks (and thus possibly be fatal).

This argument, however, is weak on its own, because most (all?) tropical and subtropical foragers do have access most of the time to resources that are consistent over long periods. In most of these groups, females are able to obtain in a given day sufficient food for their immediate needs and the needs of their offspring. Males, on the other hand, tend to forage for resources that result in occasional abundance dispersed among days of an inadequate supply. Were humans to stop sharing in these groups, this could work out as long as everybody (males included) foraged in the female style.

However, the resources that males tend to obtain from the wild (mainly meat from hunting), despite their irregularity, may serve a critically important role – or more than one role. For example, basic cellular function, especially as related to growth and the immune system, require the synthesis of many proteins that are built from amino acids. Some of these amino acids are synthesized in one’s own cells, others are not and must be ingested … typically in the form of proteins in a variety of plant foods as well as animal foods. The amino acids are not interchangeable. Almost all proteins are made from a list of 20 amino acids that occur in varying degrees of abundance in various plant foods. If you eat only plant foods, there will always be one amino acid that is the rarest of those needed, so you must ingest a larger than optimal quantity of foods. But if you eat meat, you are ingesting a perfectly balanced set of amino acids. In other words, a very efficient way of growing and in certain ways maintaining your body is to eat other animal bodies.

So, it may turn out that the highly variable sources of “balanced” proteins … mainly meat from hunting … are a critical resource for this (and other) reasons. So while day to day energy needs cannot be met among these forager groups from hunting (that comes mainly from the plant foods), the needs of growth and immune system function and general cellular processes can be met with this variable food supply. But only if it is shared.

The problem this presents is actually psychological (or maybe I should just say neurological … brain based). Apes don’t share much. When chimpanzees forage — and they typically forage for relatively rare, high quality foods — they benefit by foraging alone because this reduces competition with other chimpanzees. They do not bring the food they find to any other place than where they found it in order to consume it.

In contrast, human foragers do two critically important things. First, they bring much of the food they forage to a central place — the forager “camp” as we call it. Since all the foragers in a given group (by definition) live in the same camp, they are therefore bringing this food into direct competition with other foragers. If they were chimps, the dominant chimps would just take the food from the lower ranked chimps, or small coalitions of cooperating individuals (usually males) would take any of the food they wanted from any of the other chimps.

The second thing foragers do is to process much of this food. This processing is often essential to make these food items edible. In other words, human foragers are finding items (plant parts) that are not edible by humans, and thus constitute a kind of VERY low quality food (zero or near zero caloric value) and by processing — including cooking with fire — turn this stuff into medium or high quality food.

The only way to do this second thing (turning the inedible into the edible) is to do the first thing, to have a central place foraging style. And the only way to do this is to have a social ethic that manages the concepts of possession, ownership, sharing, and so on.

How does this ethic emerge in an individual? A little introspection and reference to experience can help answer that question. Sharing, being fair (the opposite of “cheating”), a capacity to learn and live by certain social ethics and so on, emerge over several years in children with the continuous, time consuming, and energetically costly efforts of adults.

What are the social mechanisms that are at work in this aspect of childrearing?

Are there ways in which adults, who are at a stage in their lives when they are looking for possible mates, evaluate each other with respect to these behavioral qualities? Are there aspects of the human dating/mating/marriage rituals and patterns that demonstrate this?

Are there ways in which adults demonstrate these qualities, and if so, how do others ascertain if these demonstrations are false vs. honest indicators of a sharing ethic?

How does this play out in social relationships other than mating/marriage?

Are there conditions in which sharing is the inappropriate behavior? If so, how do individuals or subsets of society balance a sharing ethic and what might be called a selfish ethic?

Do the manifestation of these behaviors vary across age and gender, or social class?

Humans are different from chimps in these critical aspects of behavior, and these differences are manifest in both ecological and reproductive aspects of human culture and society. Modern foragers demonstrate the human condition, and the way in which these problems have been solved through adaptive behaviors. What kinds of problems emerge in other kinds of human societies that have emerged only recently in human prehistory, such as agricultural societies where the value of land on which food is grown, or the efforts put into crop tending, create a new kind of resource — immobile, big, and vulnerable? What kinds of problems emerge in pastoral (i.e., cattle-keeping societies) in which the key resource is potentially VERY mobile, but still big and vulnerable? What are the resources that Western Industrial societies rely on and how is that managed? In other words, what would a list of evolutionary discordances — differences between the normal foraging way of life and other ways of life — look like?

An Evolutionary View of Humans 1: Introduction
An Evolutionary View of Humans 2: Sleep
An Evolutionary View of Humans 3: Remembering Names
An Evolutionary View of Humans 4: Sharing
An Evolutionary View of Humans 5: The Opposite Sex

An Evolutionary View of Humans 3: Remembering Names

Efe people
Ituri Forest
Anthrophoto is an
excellent source for
anthropology stock
photos

How good are you at remembering names? If you are really good … if you can hear someone’s name once and always remember it … you have a calling as a politician. If you would otherwise suck as a politician, but are good at explaining things, maybe a job as a teacher (but that requires other skills as well). In any event, you are a rare bird.

Humans have typically lived in small groups. This is especially true of foragers. Not only are these groups fairly small, but they are also fairly stable. The movement that does occur between groups is typically restricted to a larger “meta-group” consisting of a few different small groups. In other words, if you are a forager sitting around with the people you live with … the people in your “residence group” as we call it … the person sitting across from you is most likely someone whom you’ve known all your life (or visa versa, depending on your relative age).

Just as importantly, the total number of people you will know during your entire life well may stay in the hundreds. That’s total. Compare that to your own “Western” experience. Count the people in each neighborhood you’ve ever lived in (whom you knew), the people in all the different grades of school you’ve been in, and the people at all the different workplaces you’ve worked in. That is probably a large number. If it is a small number, then you don’t’ get out enough. You should get out more. At least go see a movie or something…

The point of this is that remembering names is something we have not evolved to do well for at least two reasons: 1) Everybody you run into is someone you already know (most of the time) and 2) Everybody you know is someone you’ve known for a long time, so you get a long time to remember their names.

There may be another aspect of this as well, but I simply do not know how broadly this applies across forager societies. In at least some societies, it is typical to use personal names only rarely. The day to day conversation among people in many camps and villages of which I am aware makes reference to people by kinship or other generic terms, not names. During my research in the Ituri, I participated in a long term project (as a trained helper) in which we collected demographic and physical data from a large sample of people. This was something all participants in the project agreed to do in order to maintain and grow a large and important data base. As part of this a couple of us would show up in some camp (of Efe) or village (of the horticultural Lese people in the same area) and run down the list, checking off who was still in the village, getting a body weight, a few other bits of information, etc.

There were times when I would ask, say, Joe, who that person over there was (to avoid the embarrassment of not knowing) and Joe would say “oh, that’s my sister.” Then I would say “what’s her name, you have two sisters” and Joe would yell across the compound “Hey dad, what’s my older sister’s name…”

Wow.

This would be partly because Joe would normally refer to his sister as “my sister” rather than by her name, and partly because nine years ago, Joe’s sister had a baby boy named, say, Frank, and has been since known as “mother of Frank.”

(There are of course other occasions, well known in anthropological circles, where a person cannot say a certain other person’s name. Maybe your culture prohibits you from naming an inlaw, for instance. I am not talking about this situation here.)

The point is that the Western concept of personal names and how they are used is fairly culturally specific. What seems like a common deficit, the general difficulty we have in remembering names when we first hear them, is actually quite expected.

There reason you can’t remember anyone’s name is because there are too many names to remember and you haven’t had a chance yet. And evolution. Not your fault.

An Evolutionary View of Humans 1: Introduction
An Evolutionary View of Humans 2: Sleep
An Evolutionary View of Humans 3: Remembering Names
An Evolutionary View of Humans 4: Sharing
An Evolutionary View of Humans 5: The Opposite Sex

An Evolutionary View of Humans 2: Sleep

Efe people
Ituri Forest
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There has been much recent discussion on sleep in the blogosphere, and everyone, especially those who sometimes have trouble sleeping, is interested in so called sleep disorders.

My understanding of modern sleep disorder theory is the following (very oversimplified): Each person has a “normal” amount of sleep that they seem to need each night. “Better” sleep is uninterrupted. You will feel lousy if you don’t get your sleep. However, if you miss the “normal” amount of sleep several nights in a row, you only need one “good night’s sleep” to totally readjust and get back to feeling normal again. (You don’t have to make up all the hours you missed … heavens, there IS a free lunch!)

Most tropical or subtropical foragers live in flimsy dwellings (or no dwelling on some nights) clustered tightly together, so, for instance if one person snores everybody hears it (though snoring is rare among foragers in my experience). My point is simply that everyone is physically close.

Even in warm areas, it gets cold at night, so there are fires. Fires have the upside of making you warm, but a couple of downsides as well. First, they need to be tended frequently. Second, adults and especially children can fall or roll into them and get badly burned.

A typical night with the Efe is, I strongly suspect, typical of any night with any tropical or subtropical forager group. At any given moment in time, somebody is asleep and somebody is awake. Those who are awake are often talking. Sometimes they are talking to each other, but often they are just talking. Telling a story that someone may or may not be interested in. I suspect that part of the constant noise making (and what may make Africa different from Australia, by the way, if you know about Australian forager ethnography) is that you don’t want to be too quiet for too long else wandering dangerous animals …. a leopard, a suid, an elephant … may stumble into your camp and cause trouble.

The person or persons who is/are awake shifts throughout then night. It is not systematic … people are not really keeping watch … it just seems to happen. Individuals sleep when they are comfortable, and become uncomfortable as the fire cools, wake up, adjust the fire, and either stay up for a while or fall back to sleep. If one child is keeping his or her family awake, this affects the entire group. And so on.

Naps during the day (as you might expect since everybody gets a poor night’s sleep by Western standards every night) are common.

Here it is in a nutshell. The Efe, and I again suspect this is typical for foragers, spend the entire 24 hour cycle sometimes awake and sometimes asleep. During the night, “asleep” is more common than “awake” and during the day “awake” is more common than “asleep.” To foragers, it’s all napping.

One could criticize this description by pointing out how it conflicts with modern medical views of sleep. But you would be wrong. It is the case that modern medical views of sleep need to be adjusted to take into account the realties of what humans have probably always done for hundreds of thousands of years (since the first control of fire, perhaps).

An Evolutionary View of Humans 1: Introduction
An Evolutionary View of Humans 2: Sleep
An Evolutionary View of Humans 3: Remembering Names
An Evolutionary View of Humans 4: Sharing
An Evolutionary View of Humans 5: The Opposite Sex