Imagine that there is a trait observed among people that seems to occur more frequently in some families and not others. One might suspect that the trait is inherited genetically. Imagine researchers looking for the genetic underpinning of this trait and at first, not finding it. What might you conclude? It could be reasonable to conclude that the genetic underpinning of the trait is elusive, perhaps complicated with multiple genes, or that there is a non-genetic component, also not yet identified, that makes finding the genetic component harder. Eventually, you might assume, the gene will be found. Continue reading Is Human Behavior Genetic Or Learned?
Tag Archives: Behavioral Biology
The rat in the can effect
To find out more about the rat in the can effect, you can read this book: The Tangled Wing: Biological Constraints on the Human Spirit
Whitey Bulger Dead, and the Trivers Willard Hypothesis
The original version of this post was called “Whitey Bulger Caught, and the Trivers Willard Hypothesis.” A while after that, I wrote a post called “Whitey Bulger Convicted, and the Trivers Willard Hypothesis.” Today, it was announced that Whitey Bulger, Boston crime boss, is dead at 89. Thus, the new title.
Most of you won’t know who Whitey Bulger is. He was for a while on the FBI’s ten most wanted list. He spent a lot of time overseas running from the Feds, but they eventually caught up with him, convicted him, and tossed him in jail.
Whitey was top dog in Boston’s Winter Hill gang. His brother was a Senator for the Commonwealth of Massachusetts, and served as Senate President for several years.
It is said that Whitey was an FBI informant, and that his handler, FBI Special Agent John Connolly, tipped Whitey off that he was about to be indicted on racketeering charges. No problem. Whitey had left stashes of cash in safe deposit boxes all around the world, in preparation for the day he had to go on the lam. So he took off in 1995. Special Agent Connolly spent several years on vacation in the stir.
I remember when Whitey disappeared, and ever since then, I’ve used him almost annually in lecture material describing the Trivers-Willard hypothesis. It goes like this:
The Trivers-Willard model (I prefer to call it a “model” rather than a “hypothesis” because it is not specific enough to really be a hypothesis … it’s a model that generates lots of hypotheses) states that selection should favor the ability to differentially bias investment in offspring by sex if the two sexes have differential variances in reproductive success, and if there is any way to predict offspring rank. That’s a bit thick, so it requires some examples and further explanation. Maybe a story about a mobster would help..
OK, so an example: Red deer (also known as Elk) give birth to one offspring (max) per year. Males compete for access to or to be chosen by females. So, only a small percentage of male red deer mate in a given year, a significant percentage may never mate at all, and a very small percentage sire many many little red deer. Male red deer have a high variance in reproductive success. If you tried to predict how many offspring a given randomly chosen male would have, knowing nothing at all, your best guess would be the average number of offspring red deer have in an average lifetime. But you would be wrong almost every time because the actual number is highly variable. Male red deer have high variance in RS.
Females, on the other hand, have a pretty standard number of offspring. There is not much competition among them, they can always find a male to mate with, etc. If you needed to guess how many offspring a particular randomly chosen female red deer would have in a life time, you could guess the average, and you would be right on or very close. Female red deer have low variance in RS.
So, male and female red deer have differential variance in RS. Males high, females low.
If a female red deer could somehow “predict” the likelihood of her offspring getting to mate, i.e., if she could tell if any offspring she had in the present year (male or female) would be average vs. high ranking, then selection should favor the evolution of a mechanism to actually give birth to the appropriate sex offspring (thus biasing investment in one sex or the other). It turns out that she can. A female red deer that is herself average or lower-quality (thin, ill, injured) is likely to give birth to an offspring that will be either low ranking or average. But if the mother-to-be red deer is high ranking, she is likely to give birth to an individual who will grow up to be high ranking.
Under these conditions, she should have a female offspring if she’s average or low ranking, but a male if she’s high ranking. And that, it turns out, is what red deer actually do.
That should be clear. But in case it isn’t, let’s take it down do real life, and bring in the gangsters.
You check the mail this afternoon, and there is a letter from a law firm you have never heard of. It says that your Great Aunt Tillie (whom you’ve also never heard of) just died, and left you with $1,000 in her will. The check is enclosed.
This may or may not be a recent photograph of a male red deer. Holy crap. Found money! What are you going to do with it? So you and your close advisors (your roommates, your cat, etc.) discuss it and you narrow it down to two choices. Choice A and Choice B.
Choice A is to go to your broker and buy $1000 worth of a nice, relatively safe mutual fund. The fund will buy and sell reliable blue chip stocks, thus spreading the risk over several companies, and over time you can expect to get a return of 50 bucks a years, easy.
Choice B is to buy 1000 one dollar lottery tickets. Your chances of winning are slim, but if you do, you will win 87 million dollars.
So, what do you do? The obvious sane choice is to buy the mutual fund.
But what if your cousin is Whitey Bulger? Whitey Bulger, as head of the Winter Hill Gang, is said to have owned the director of the Commonwealth Lottery agency.
So now, you have two choices.
Choice A: Invest in a mutual fund and gain a return of 50 bucks a year (that’s dollars, not elk); and
Choice B: Buy 1000 PowerBall tickets and have a great deal of certainty of winning 87 million dollars.
What would you do?
In case it isn’t already clear. the baby male elk is a lottery ticket, the baby female elk is a mutual fund, but the female can guess pretty accurately if the lotter ticket (male offspring) will pay off. Because the elk’s cousin is Whitey Bulger. See?
Aging in men: An evolutionary perspective
Many years ago, Mel Konner, Marjorie shostak, and Boyd Eaton wrote “The Paleolithic Prescription: A program of diet and exercise and a design for living.” (It is hard to find these days. To find it and related titles on Amazon, look for this book first, and track the PP down via the author name Konner
(Added: You can probably get the The Paleolithic Prescription here
The researchers noticed that there were differences in lifeways between these exemplary foragers and industrialized people’s of the West that seemed related to health and well being. They were able to link, sometimes definitively, sometimes tentatively, diet and activity levels on one hand and health on the other. Their findings, by the way, were first published in the peer reviewed literature, then turned, by the scientist themselves, into a popular book. (One of the findings eventually led to the understanding that there are different kids of cholesterol, which seem to have very different health related implications.)
My own research with the Efe (Pygmies) of the Ituri Forest, in Zaire, was an indirect offshoot of that early work. I got my PhD at the same institution, Harvard’s Anthropology Department that housed much of the Kalahari project, and the Ituri project was started by the same leader, Irv DeVore, via his students. So, the tradition of examining the lifeways of modern day foragers, in part to understand ideal human conditions, and comparing those conditions to western ways continued.
Meanwhile, one of the graduate students at Harvard, Peter Ellison (yes, he is related to that Ellison) had been interested in some work coming out of Harvard Medical school looking at hormones and behavior, especially as related to reproductive biology of human women. Building on that work, Ellison created an entirely new field of study, called “Reproductive Ecology.” He finished his PhD and was added to the faculty at the Anthropology department in one of those in between positions (as was I and many others over the years) but Peter became one of the very few such individuals to be eventually offered a tenured position with the most “always hire from outside” institutions ever. And Ellison created the Reproductive Ecology Lab within the biological anthropology wing of Harvard’s Department of Anthropology.
And, they studies the heck out of female reproductive ecology. I had the pleasure of working, almost every semester that I was there from late in my PhD cycle through my post-PhD teaching career there, to work with Mary O’Rourke (and others) who were from that lab running an undergraduate tutorial. The tutorial is three or four faculty members each running two or three groups, with about five or six students in each group. These are students majoring in Biological Anthropology, who have already taken a class or two but are on their way into the research labs. The tutorial instructors’ job is to turn these young and interested minds into the minds of proto-Anthropologists by carefully examining a different topic each week, looking at a combination of peer reviewed literature and secondary but excellent literature (back in those days, the former was easier to find).
So, I spent a lot of time hanging around with the Reproductive Ecology people (and, by the way, collecting some of their data in Zaire). Every social event had a lot of Repro Eco folks at it, so it was pretty normal for someone to pull out a box of specially prepared test tubes to get every one to provide saliva samples for some study or another. It was not long into the process of developing this subfield that the reproductive ecology of men, simpler but still important, was also taken up by this group, so everyone had an opportunity to spit into the tubes. For example:
Hypothesis: Testosterone in men varies over short time scales (of minutes, hours) during a poker game depending on which cards they are dealt, assuming the samples are not contaminated by …
… oh, never mind, you get the picture.
Anyway, it was while I was a couple of years into my own graduate career when a young man from California showed up to study anthropology, with a particular interest in Biological Anthropology. It was Richard Bribiescas. Rick and I did not hang around a lot of time, because we were both busy, but we were good friends and broke bread (a euphemism for guzzling beer but there were also tacos and cheeseburgers) quite often.
When Rick got to Harvard, there was already a strong tradition of working to understand modern human problems in the Western world by examining modern human behavior and physiology in a variety of other societies, including foragers.
Many young men and women went to the field from that department, to work in Poland, Borneo, the Amazon, the Congo. Among those, very few attempted to work in the most difficult of conditions, in a rain forest with foragers. Of those who tried most retreated and picked another topic. A few persisted and continued to study this or that thing about one of the few remaining forager group son the planet. That’s what I did, with the Efe. That’s also what Rick did, with the Ache, of South America.
And, as a result of that, Rick produced a bunch of interesting peer reviewed papers, and eventually, a book that has been out for a while now called Men: Evolutionary and Life History
And now, Rick is an old guy. He must be at least 45. And, as such, he has turned his attention to a new but related topic: How do men age. And, the newly produced book that comes from this research to your book shelf is How Men Age: What Evolution Reveals about Male Health and Mortality
Do not buy or borrow some book on aging written by a web site, a fake MD, or some other charlatan. Read a book on aging (in men) that first appeared many times in the peer reviewed literature, written by Harvard Trained Yale Expert Richard Bribiescas.
Note the subtitle. This is about what evolution reveals about male health and mortality. Having taught along side him many times, and after all those beers, tacos, and cheeseburgers, I can tell you that Rick knows all about evolution, and of course, he is the world’s leading expert on male reproductive ecology.
I put the Table of Contents below to give you and idea.
Rick is a great writer, and this book is fun to read.
Do the well known features of male aging have some sort of evolutonary advantage, as has been proposed for females? How much of male aging in the West is a function of our Western lifestyle, or a function of our seemingly extended lifespan? What about the contradiction between what we mere humans think of as “health” or “healthy” and what the cruel and cold process of Darwinian natural selection things about such silly things? What about sex, relationships, monogamy, polygamy, fatherhood and child rearing, in male humans in general, and across the aging process? And our brains, our obscenely large brains, what the heck are they for?
You will enjoy this book, especially if you are a man of a certain age.
Table of Contents:
Acknowledgments ix
Chapter 1 A Gray Evolutionary Lens 1
Chapter 2 Dead Man’s Curve 17
Chapter 3 Getting a Handle on Love Handles 45
Chapter 4 Older Fathers, Longer Lives 70
Chapter 5 Dear Old Dad 88
Chapter 6 Darwinian Health and Other Contradictions 106
Chapter 7 Older Men and the Future of Human Evolution 133
Notes 145
Index 169
In homage to an inspiration of this post, I provide this link to the secret, generally unseen obituary of Professor Irven Boyd DeVore.
Do genes make you gay?
Of course they do. To the extent that genes make you anything in particular, though the role of genetics in human behavior is pretty limited.
You’ve probably heard about the newly reported research in which a genetic link was found to homosexuality in a study of gay brothers. Kelly Servick has a good writeup on it here. The study looked at 409 pairs of gay brothers, and found a region on the X chromosome that was similar across the sample. This sort of shotgun approach, comparing a trait (in this case, gayness) with a bunch of DNA (I oversimplify) is very likely to get results that look real but are the result of random association. But, it is also possible to find real links. I am agnostic as to whether or not this study found something interesting. But I do have a few remarks to make about how you get to be gay.
Consider the following list of things:
<li>Sexual attraction (to whom you are attracted)</li>
<li>Erotic response (what is erotic, including physically, to you)</li>
<li>Attachment (with whom to you seek attachment, and of what kind)</li>
<li>Sex drive (do you have it and where is it driving too?)</li>
<li>Society norms (especially for your subset of society)</li>
<li>The details of social norms, i.e., what categories of sexual orientation exist around you.</li>
<li>Your relationship to social norms (your comfort level ... do you seek "normalcy" or prefer something else?)</li>
<li>Whom you know or encounter and where they are with all of the above things.</li>
<li>And many more things that ultimately may relate to sexual orientation.</li>
This list can be written in many different ways, and every item on this list really represents a number of other sub items. These things are not mutually exclusive and the list is not exhaustive of that which relates to sexual orientation. Feel free to provide your own lists in the comments, if you like.
Many, most, maybe all of these things have individual ontogenies for any individual. The ontogenies may start before birth. We are bathed (or not) in various maternal hormones in utero. We are bathed in our own hormones in utero. The effects the hormones have depend on the relationship between the amount of hormone and the abundance and distribution of receptor sites, and on the timing. The abundance and distribution of receptor sites itself is probably influenced by the process. It is very complicated. Differences between one individual and another may related to external or non-genetic factors. In fact that may be very common.
Hormonal effects and interactions continue after birth. Again, timing, relationships between kinds and relative amounts of hormones, and receptor sites, still apply. Causes may be numerous.
The above only applies to that related to hormonal changes, which may affect a number of somatic (body related) features including brain features.
Then there are the non-hormonal factors, including cultural and social ones. Again there are complexities to the ontogeny of an individual with respect to these factors. And, these complexities are dynamic; culture and society can change right underneath you. And the non hormonal and hormonal factors may interact.
Much of this can be thought of as a process of negotiation. One negotiates internally, one negotiates with one’s social groups, one negotiates with society, culture, even the law.
Here is a simplified model linking the DNA identified in this study to homosexuality. Various switches are turned on or off, buttons pressed or not, during a person’s development. They do everything in some individuals to “make a person be gay.” But there is one element missing. If you have the DNA profile associated with the sample of 409 brothers, you get to be gay. If not, you probably won’t be. But, the “yes-no” value (reminder: oversimplifying here) found in this DNA actually has another purpose. It has to do with how many hairs you have on the back of your hand. The variation across men in hand hair is accounted for by variation in these genes. But in some individuals (but not all) it also happens to be the final ontogenetic link in the chain to a particular sexual orientation that in the sociocultural context that the 409 pairs of men live in results in gayosity. In another society, another culture, at another time, it results in being more likely to be a blacksmith than a farmer.
Note: That was a made up example. But in the absence of a biologically, developmentally, sensible link between some DNA and a trait, we can certainly carry out amusing and instructive thought experiments.
This complexity of links between causes and effects is probably true for the vast majority of variation found in human behavioral traits. Not this exactly, but something like this. The steps involved can be characterized in a certain way with respect to a trait under study, but all or most of those steps actually relate as well to other things. Also, some of those steps might have multiple causes. A particular manifestation of sexual or erotic attachment may arise in one person for one reason, in a different person for a different reason. In other words, the list I provide above can take many forms, not just because I’m being vague about what is in the list. The list can simply be different for different people who end up with the same “trait” as we happen to define the trait for the moment.
There is a reason for this vague connection, or in many cases, lack of connection, between inherited genes and behavior. A strong link between genetics and behavior has been shown to be very highly adaptive in some organisms. Here’s an old example. In a particular species of fruit fly, the larvae have a gene with two alleles. One allele causes the larvae to forage tightly in space, making a lot of turns in its search for food. The other allele causes the larvae to forage widely, to make few turns, and cover a larger area. Each allele is adaptive in a particular context and the fruit fly species has diversity at this locus. So, the fruit fly female mates with multiple males, produces a diverse batch of offspring, and the ones with a particular pattern of alleles at that locus have higher fitness. For now. In a different environment, maybe a few generations later (as the orange juice they are feeding on changes its characteristics as it rots in that glass you left on your desk) the genetic arrangement with the higher fitness changes.
But, humans are different. Humans are like the fruit fly, needing different traits at different times, but instead of those traits being programmed by genes, they are learned. Added on to the individual by enculturation.
This applies to some extent to all mammals because mammals have brains that matter to behavior. It applies very much so to primates, especially apes, and even more to humans. We have diversity in behavior, but we get it from our cultures. We learn to be a functioning adult; it is not pre-programmed. There probably are some pre-programmed behavioral features, but those are the features that would generally apply. But even those may be largely divorced from genetic inheritance on the grounds that behavior generally does not emerge from genes coding for neural structures. Genes in humans can’t code for neural structures at the level of the cerebrum, because of the way cerebrum develops, and that is where most of the relevant behaviors exist.
We can be pretty sure this is the case because of the huge cost we pay for it. Childhood. Childhood may be the most important human adaptation, and it may be the most costly. Human females can die in childbirth. That is nearly unheard of among mammals, outside of humans and our domestic stock. The babies can die in childbirth as well. That is because of our oversized brainy heads. Human babies are born helpless and spend several years nearly killing themselves at an alarmingly high frequency, and only survive childhood because of the adult humans taking care of them (or in some cases, wolves or ocelots, I suppose). This is costly to the adults. It limits reproductive output in the adults. Childhood also limits the reproductive output of the child, because it extend the time before reproduction, and decreases the chance of survival until reproduction.
Childhood, a brain that learns, the heavy reliance on the things the brain learns, and the long time it takes to make all this work demands a brain that is not overly programmed genetically, and results in a species with an extraordinary characteristic found in no other species: we are a multitude.
If you look at numerous species in most mammal families, you will find a wide range of behavioral and ecological repertoire. Measure body size, sexual dimorphism, typical system of mating, food getting, diet, defense, inter and intra species competition, etc. across all of the geomyids or voles, across all the species of dogs or all the species of cats, across the antelopes, across the African forest monkeys, etc. and you’ll find many features such as those mentioned that vary very little within species, but vary greatly across them within that taxonomic group.
Then look at humans. They look more like a taxonomic family than a species. Human cultures vary in these and other features as greatly as larger mammalian taxonomic groups.
But, when you capture an infant at birth from one human group and have it raised by another group, the infant grows up with behaviors typical of the adoptive group, not its natal group. That pretty much falsifies the idea that variation in our behavior is linked to variation in our genes.
By the way, if you move new born antelope, rodents, primates, etc. between species you may get some of the same effect. Cross species adoption does result in a bit of a behavioral chimera sometimes. But, it is only possible between some species and tends to work when the interactive parts of the system happen to be aligned. A parent bird will feed mouth-gaping carp for a while if they’ve lost their mouth-gaping baby birds. Within mammals, we’d expect a fair amount of post adoptive learning across species, because, as I noted above, learning how to be typical member of your species applies to some degree to mammals in general, more so to primates, more so to apes, and vastly more so to humans. Vastly.
Imma let you get back to finding links between genes and behavior. But first, remember, culture rules.
Final note. Part of the reaction to this new research, and this has happened with all prior research on homosexuality, is in reference to the sociopolitical outcome. If you are born gay, Conservatives can’t legislate against you, but if it is a choice, you might be a criminal. That sort of thing. This is balderdash. The Nazi’s killed all those people because of their genes. Many value free choice. Some will see being born gay as being born broken. People who are born a certain way, in many sociopolitical contexts, are vilified for it. You can’t win the sociopolitical game by claiming a certain human behavior or trait is built in or choice. You win that game on its own terms. And, lately, we mostly are winning.
Does Your Genealogy Reveal Amazing Anthropological Stories?
I gave a talk at the Brookdale Public Library last night as part of the celebration of DNA day. DNA Day, or DNAD for short, was created about the time of the “completion” (more or less) of the Human Genome in 2003, and is set to be on the date of the publication of the famous research on the structure of DNA.
The point of the talk was to link behavioral biology and the anthropological study of kinship with the practice of conducting personal genealogy. There was a time when I did a fair amount of genealogical research, in connection with historic archaeology, which in turn was part of writing environmental impact assessments for publicly funded projects such as sewer systems, power plants, road improvements, and such. It is useful to know something about the people who lived on affected properties (or in affected buildings) back in the 18th or 19th century when assessing the potential significance of cultural resources, and genealogical research is part of that. Also, property research and genealogical research often go hand in hand.
At the time, I noticed a few interesting possible patterns emerging in the genealogical data, though I was never able to devote enough time to any of the projects to really narrow them down. For instance, one pair of families that lived mostly on or near Cape Cod, Massachusetts seemed to intermarry more than one might expect, almost resembling the time honored practice of “sister exchange” in some cases. Also, the two parallel families, who frequently engaged in property related ventures together, seemed to mainly follow two distinct geographically based economic strategies; one family lived mainly in the interior and farmed (among these farms was the first commercial cranberry operation in the US) while the other family lived mainly on the coast and engaged in shipping. Among the latter, one individual held the record for a time in the number of days to leave a Massachusetts port in a clipper ship, sail to Canton to load up with stuff, and return.
For decades, cultural anthropologists fixated on kinship (and associated marriage patterns and inheritance rules) as a central organizing principle in culture. This made sense for a lot of reasons. It seemed that any given culture had a sterotypical system of specifying relationships between people. These systems were not random or even that diverse; all the kinship systems studied across the world could be categorized into a few standard patterns. Perhaps one of the most striking things to European and American (Western) anthropologists was the frequent reference to kinship. In some societies, many individuals were referred to almost exclusively by kinship terms, with individuals’ given names rarely uttered. Social relations beyond just marriage or inheritance seemed to be determined by kin relations. And so on.
Over time, however, a couple of things happened. Three, probably. For one, even though all societies seemed to have a kinship system and all kinship systems could be classified into a short list of patterns, it also seemed that the kinship system observed by different anthropologists visiting a given “culture” at different times and places was sometimes different. Either kinship systems were more diverse or dynamic than previously thought, or their role in organizing society was weaker than imagined, as a system that is in flux would seem a poor starting point for a culture’s organization. Also, anthropologists were confused and confounded by the apparent fact that only some kinship systems mirrored an underlying biological reality very well. Many societies had and “underdetermined” system where, for instance, all the women and men in the generation above “ego” were called mother and father, respectively, even though they could not all be mothers and fathers. Other systems were “overdetermined” whereby individuals seemed to be classified into categories that broke atomistic biological systems down to smaller parts. Finally, it became a pattern in cultural anthropology to build up a way of thinking about culture and then, no matter how useful that way of thinking became, to toss it out and replace it with another. Models of culture among anthropologists were, it turns out, more dynamic than kinship systems within cultures!
About the same time that cultural anthropologists were both figuring out kinship and beginning to discard it as intractable or uninteresting, biologists were busy linking genetic relationships to behavior, a form of study that would eventually take shape in Sociobiology, Behavioral Biology, and Darwinian Anthropology, and Evolutionary Psychology (and no, none of those terms are really interchangeable, though there is overlap). Eventually it would become apparent to many of us that the “overdetermined” kinship systems actually do reflect an underlying biological reality, and we could understand why a patrilineal system with female exogamy and prescribed cross cousin marriage made sense from a behavioral biological point of view. Too bad the biologists and the cultural anthropologists were not more in sync, because we might have had some interesting conversations.
When a married man dies, his wife may become the wife (maybe the second or third wife) of his brother. When a man is married to more than one woman, it is more convenient for many involved in that relationship if at least two of the women are sisters. Under some conditions, more than one man will reside with and father the children of one woman, and in some cultures that is openly acknowledged, while in most, it is not. As mentioned earlier, women are often exchanged between patrilines over time, sometimes in the practice of sister exchange. Cousins, in some cases a particular kind of cousin, are often preferred marriage partners. And so on and so forth. These are all practices that have been identified in a number of societies. These practices are often explicitly defined, even given a name. There is probably a reasonable correspondence between a society’s economic base (or other factors) and whether or not any one of these practices is found. These things are seen all around the world.
However, most of these practices are explicitly or implicitly either prohibited or frowned upon, or simply ignored and unacknowledged, in Western society. Western society is one place where a fair number of people engage in systematic genealogical research. What this means is that when people do this genealogical research, they may be missing something, missing patterns, revealed by the relationships in their ever growing and ever more detailed family trees.
The other day, Amanda, Julia and I watched a film made by my sister, set in a geologically complex, active, and interesting part of the world. As someone with more than a passing knowledge of geology, I was enjoying the background as much as the foreground in that film. I especially appreciated the amazing thrust fault that showed up in many of the scenes, not to mention the broken ancient peneplains raised up by mountain building. At one point I stopped the film, rewound, and made everyone else notice these details! (I know, that must have been annoying.)
This is how I feel about Americans doing genealogy. As an anthropologist and behavioral biologist, I want those folks to at least have a chance to notice some of the interesting things they must be seeing here and there in their research.
After my talk audience members shared their observations. In fact, each of them could point to things in their genealogies that at first perplexed them, but that now they suddenly felt a better understanding of.
And, as individuals, they will never look at their cousins in the same way again.
Image from Wikipedia Entry on Kinship
How Do You Get Sexual Orientation and Gender in Humans?
Humans appear to have a great deal of variation in sexual orientation, in what is often referred to as “gender” and in adult behavior generally. When convenient, people will point to “genes” as the “cause” of any particular subset of this diversity (or all of it). When convenient, people will point to “culture” as the “cause” of … whatever. The “real” story is more complicated, less clear, and very interesting. And, starting now, I promise to stop using so many “scare” quotes.
Continue reading How Do You Get Sexual Orientation and Gender in Humans?
The Kiss
Valentine’s Day is coming up, so it is time to think about kissing. Pursuant to this, Sheril Kirshenbaum, author of “The Science of Kissing,” has made the Kindle version of her excellent book available at a discounted price through February 18th. The book is here: The Science of Kissing: What Our Lips Are Telling Us
I went out with a friend. We were both between relationships, and we both knew somehow that this was a date though it was never called a date. And we had a perfectly good time: Good food, good conversation, good drinks. She drove.
When it came time to go home, she drove me to the urban neighborhood I lived in and parked on the street near my house. As we were saying our good-byes, she enigmatically unhooked her seat belt. I wondered why. Then, I discovered that she wanted the freedom of movement to lean across the console and give me a kiss. It was a good kiss. It was actually a series of good kisses, and it went on for a while.
And suddenly, there was a loud rapping on the window of the car. We stopped kissing and that’s when we noticed that we had steamed up the windows a bit. So I cracked the window on which the rapping had occurred and there was a policeman staring in with his flashlight.
Continue reading The Kiss
A Tutorial in Human Behavioral Biology
If you read only one book this holiday season, make it all of the following twenty or so!
But seriously … I’d like to do something today that I’ve been meaning to do, quite literally, for years. I want to run down a selection of readings that would provide any inquisitive person with a solid grounding in Behavioral Biological theory. At the very outset you need to know that this is not about Evolutionary Psychology. Evolutionary Psychology is something different. I’ll explain some other time what the differences are. For now, we are only speaking of fairly traditional Darwinian behavioral theory as applied generally with a focus on sexually reproducing organisms, especially mammals, emphasis on humans and other primates but with lots of birds because they turn out to be important.
Continue reading A Tutorial in Human Behavioral Biology
Driving The Patriarchy: Demonic Males, Feminism, and Genetic Determinism
Behaviors are not caused by genes. There is not a gene that causes you to be good, or to be bad, or to be smart, or good at accounting, or to like bananas. There are, however, drives. “Drives” is a nicely vague term that we can all understand the meaning of. Thirst and hunger are drives we can all relate to. In fact, these drives are so basic, consistent and powerful that almost everyone has them, we share almost exact experiences in relation to them, and they can drive (as drives are wont to do) us to do extreme things when they are not met for long periods of time. While eating disorders are common enough and these affect a hunger drive, it is very rare to find a person thirst themselves to death.
Continue reading Driving The Patriarchy: Demonic Males, Feminism, and Genetic Determinism
New Pig Species Discovered
A new species of peccary has been discovered in the Amazon. It’s different from other peccaries in that it appears to be a frugivore. It also lives in pairs or very small family groups. This is, of course, exactly what one might expect. Frugovores eat high quality food, while the other peccaries eat lower quality food. Higher quality food is rare and dispersed so it is difficult to get into larger groups. Continue reading New Pig Species Discovered
Parasitic Birds and The Red Queen Effect
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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