Baumeister on Sexual Economics

November 9, 2012  |  Evolution  |  2 Comments

Many academic papers are dry. Baumeister’s latest is definitely not. From Sexual Economics, Culture, Men, and Modern Sexual Trends:

The fact that men became useful members of society as a result of their efforts to obtain sex is not trivial, and it may contain important clues as to the basic relationship between men and culture (see Baumeister 2010). Although this may be considered an unflattering characterization, and it cannot at present be considered a proven fact, we have found no evidence to contradict the basic general principle that men will do whatever is required in order to obtain sex, and perhaps not a great deal more. (One of us characterized this in a previous work as, “If women would stop sleeping with jerks, men would stop being jerks.”) If in order to obtain sex men must become pillars of the community, or lie, or amass riches by fair means or foul, or be romantic or funny, then many men will do precisely that. This puts the current sexual free-for-all on today’s college campuses in a somewhat less appealing light than it may at first seem. Giving young men easy access to abundant sexual satisfaction deprives society of one of its ways to motivate them to contribute valuable achievements to the culture.

Odd Fact: you aren’t related to most of your ancestors.

September 15, 2011  |  Evolution  |  No Comments

John Hawks, on the mathematics of family trees and recombinant DNA:

In practice, even though we have billions of nucleotides, our DNA cannot follow billions of genealogical lines. Recombination over 30 — 40 generations does not divide chromosomes down to individual nucleotides. In the medium term, most human DNA is separated by recombination hotspots into lengths of around 50 kilobases. Across very short spans of 30 generations, DNA is for the most part inherited in chunks of hundreds of kilobases or longer. So dividing six billion nucleotides by 50 kilobases yields a number of around 120,000 ancestral lines at most from which any individual inherits his or her DNA. Recombination will increase this number somewhat further and further back in time, but not nearly so fast as the doubling of possible ancestral lines in every generation. This means that the vast majority of your ancestral lines more than around 17 generations ago have left no DNA to you whatsoever.

Granted, this is relative to the massive redundancy in our family trees– humankind is one huge, partially-inbred extended family. I.e.– if you go back 40 generations, you have over a trillion great-great-great-(etc) grandparents. There weren’t a trillion people alive in 1000AD, so a lot of those slots were filled by the same people.

Cognitive enhancement and a new social contract

November 12, 2010  |  Evolution  |  4 Comments

Many serious people are projecting that within ten to fifteen years we’ll be able to start on a significant program of cognitive enhancement. To craft drugs, hormone cocktails, neurointerfaces, and neuroprotheses that will significantly make their users smarter and more capable, initially to a degree perhaps comparable to the invention of literacy or science, but soon far outstripping any previous transition in the history of the human mind.

If we grant that this is possible, the only real debate is when. 10 years? 15? 50? 100? The gears of capitalism and human nature ensure that it’ll come, sooner or later. And I think the only way this won’t end in certain disaster is to develop, formalize, and enforce a new social contract regarding human enhancement.

My suggestion? If you want to use biotechnology to make yourself smarter, you also have to use it to make yourself nicer.

If we don’t make this the accepted contract, I fear we’ll ping-pong between two unpalatable scenarios: either open things up to an enhancement free-for-all (and there’s likely a strong correlation between people who most want to be cognitively enhanced and people for whom it’s not in society’s best interests to grant a competitive advantage), or criminalize enhancement (and if we outlaw enhancement, only outlaws will be enhanced).

Quote: on the evolution of reading

September 30, 2009  |  Evolution  |  5 Comments

Here, I am reminded not of the recent past but of a huge change that occurred in the middle-ages when humans transformed their cognitive lives by learning to read silently. Originally, people could only read books by reading each page out loud. Monks would whisper, of course, but the dedicated reading by so many in an enclosed space must have been an highly distracting affair. It was St Aquinas who amazed his fellow believers by demonstrating that without pronouncing words he could retain the information he found on the page. At the time, his skill was seen as a miracle, but gradually human readers learned to read by keeping things inside and not saying the words they were reading out loud. From this simple adjustment, seemingly miraculous at the time, a great transformation of the human mind took place, and so began the age of intense private study so familiar to us now; whose universities where ideas could turn silently in large minds.

Dr. Barry Smith, University of London, while discussing Edge Magazine’s 2009 question, What will change everything?

Edit: a commenter has suggested it was actually St. Ambrose, not St. Aquinas, who first broke this ground.

Brainstorm: An alternative to the tree of life

May 12, 2009  |  Evolution  |  No Comments

One of the greatest insights of modern biology is the Tree of Life metaphor– that all organisms share common ancestors if we go back far enough, and that we can understand a great deal about an organism based on which evolutionary forks it and its ancestors have taken.

This has been and continues to be a profoundly useful tool in nearly all subfields of biology. But it was created before we knew anything about genetics, and it’s starting to show its age– especially in the context of single-cell organisms, whose cellular machinery and evolutionary history allow organisms very far apart in the ‘tree’ to readily swap significant amounts of genetic material.[1] This sort of gene swapping, or Horizontal Gene Transfer, as it’s called, happens in plants and animals as well– think of mitochondria and chloroplasts, once organisms in their own right, now mere cellular power plants with much of their original genetic code shuffled into their hosts’ genomes.[2] But as a rule, most HGT happens in the contexts of bacteria and viruses. And HGT is extremely common there.

So we have these concepts of distinct species and this branching tree of life, and they’re incredibly useful when talking about plants and animals, but in the contexts of bacteria and viruses they become rather strained when organisms from very distant branches constantly share lots of genetic code. The core organizing assumption which gives the tree metaphor and our current phylogenic system meaning, that once organisms branch off sufficiently far from each other they can no longer share genetic code, is often false in these contexts.[3] And under many metrics, most of life’s genetic diversity is contained in the bacterial and viral domains, so this is not a trivial problem.

So we can keep trying to extent the current tree metaphor, or we can start looking around for a new model.[4] I think both are worth doing.

So what would an alternative to the Tree of Life look like?

I don’t have an answer to this per se, but it seems to me the way forward is to recognize the core insight of the tree metaphor- to group things that have more shared evolutionary history closer together- but to apply this insight at the level of the gene rather than the organism. Essentially, I think a new system could be built by sequencing everything and having computers crunch the numbers, identify co-evolved gene clouds, highlight the genetic links between organisms, and sort organisms based on these links.

This approach could simplify down into or replicate most of our current phylogeny in organisms with low HGT (eucaryotic organisms are mostly isolated co-evolved gene clouds which should be grouped together, and grouped near the other eucaryotic organisms they share recent history with) while leaving the door open to a more elegant treatment of the edge cases of e.g., bacteria and viruses, which may be amalgamations of distinct co-evolved gene clouds with separate evolutionary histories.

But the devil will be in the details, and creating a new phylogeny is particularly tricky in that any sorting algorithm includes contingent assumptions about what sort of answer we want when asking, what is the nature of the relation between organism X and organism Y?

It’s interesting to think about. Realistically speaking, our current phylogeny is much too fundamental to most of modern biology to be replaced anytime soon. But it’ll be interesting to see if and how people attempt to apply the gene-level shared history idea to patch up our current organism-level shared history phylogeny.

Footnotes:

[1] This rampant HGT happens in multiple ways: bacteria can share plasmids, which are sort of modular pieces of genetic function able to be easily swapped in and out. If one strain of bacteria develops resistance to a drug, it may share that resistance to other strains through a plasmid. Bacterial DNA is also less isolated and protected than eucaryotic DNA, so ‘free floating’ DNA is much more likely to be integrated into the cell.

Viruses, on the other hand, exist by hijacking existing cellular machinery to splice themselves into genomes then copy themselves, and evolve resistance by being extremely sloppy in their duplication methods, both of which can lead to significant HGT. As well, viruses are hardly limited to infecting plants and animals; those which infect bacteria and other viruses (bacteriophages and virophages, respectively) can also be vehicles for HGT.

[2] Our genomes are filled with ancient, defunct viruses who spliced themselves into our genes but then couldn’t get out. Recent surveys of the human genome indicate that these defunct viruses take up more space in our genome (2%) than do actual protein-coding genes (1.4%).

Recent research indicates that this has been a useful source of genetic diversity: the mammalian placenta, for instance, repurposes genes originally from an ancient retrovirus to protect itself from being attacked by the mother’s immune system.

[3] That’s the conceptual argument for a new type of phylogeny. The pragmatic argument is that an infectious bacteria or virus’s position on the tree of life does not tell us much about how it spreads, where in the body it can thrive, or how to treat it. It would be nice to have a phylogeny that would naturally indicate such things.

[4] A possible extension of the tree metaphor is put forth by Frederik Cohan of Wesleyan University, who suggests adding an ‘ecovar’ notation (short for “ecological variant”) to bacteria and viruses. As Carl Zimmer so succinctly puts it, “The bacterial strain that caused the first recorded outbreak of Legionnaires’ disease in Philadelphia, for example, should be called Legionella pneumophila ecovar Philadelphia.”

Notes:

It may be neither here nor there, but in writing out a wishlist of the perfect phylogenic system, I came up with that it should deal with the following:
– Common descent, evolution of major function, and speciation (as the tree metaphor currently does);
– HGT (specific gene chunks that were transfered, and past lineages & other signifying metadata of those genes);
– Phenotype & function: cellular mechanics/architecture and proteomic profile (trying to classify organisms in terms of what goes on ‘under the hood’);
– Current ecological niche (e.g., Cohan’s ‘ecovar’ notation).

Others’ lists may differ.

Ed Boyden, Roy Baumeister

September 26, 2007  |  Evolution  |  2 Comments

Ed Boyden, a neuroscientist over at MIT/Technology Review, has started a general-interest science blog. I’m happy to see this, as Ed seems not only smart, but prone to write frankly and creatively about deeply relevant issues.

Another interesting, rather speculative piece I’d direct people toward is “Is There Anything Good About Men?” – American Psychological Association, Invited Address, 2007, Roy F. Baumeister.

I’ve not decided whether I agree with his conclusions, and since it’s a conference address it’s a little citation-lite, but it’s a thoughtful and thought-provoking mix of fact, theory, and conjecture.

Back to paper writing.

Quote of the Week: July 8

July 11, 2007  |  Evolution  |  No Comments

I wasn’t sure about whether to keep up my weekly quotes during this month of science, but since I found one that connects rather ironically with my next science topic, I took it as a sign. This quote is from Jack Cohen in “Is Biology Science?”

In summer 2002, I was at the Cheltenham Festival of Science. Lots of biologists presenting, for sure. But… one very popular event was a presentation by three famous astronomers: ‘Is There Life Out There?’ I prefaced my first question to them by a little imaginative scenario: three biologists discussing the properties of the black hole in the middle of our galaxy. It was very clear that the astronomers really believed that they could discuss ‘life’ professionally, whereas everyone saw biologists talking about black holes as absurd.

Physicists sometimes seem to think they’re the superstars of the academy (especially, say, compared to sociologists). Does doing all that rigorous math and modeling give one a special license on truth or just go to one’s head? As the son of a physicist, I have no comment. :)

Quote of the Week: April 29

April 29, 2007  |  Evolution  |  No Comments

From “Scientific Success: What’s Love Got to Do With It?” via gnxp.com:

Several years ago, Satoshi Kanazawa, then a psychologist at the University of Canterbury in Christchurch, New Zealand, analyzed a biographical database of 280 great scientists–mathematicians, physicists, chemists, and biologists. When he calculated the age of each scientist at the peak of his career–the sample was predominantly male–Kanazawa noted an interesting trend. After a crest during the third decade of life, scientific productivity–as evidenced by major discoveries and publications–fell off dramatically with age. When he looked at the marital history of the sample, he found that the decline in productivity was less severe among men who had never been married. As a group, unmarried scientists continued to achieve well into their late 50s, and their rates of decline were slower.

“The productivity of male scientists tends to drop right after marriage,” says Kanazawa in an e-mail interview from his current office at the London School of Economics and Political Science in the United Kingdom. “Scientists tend to ‘desist’ from scientific research upon marriage, just like criminals desist from crime upon marriage.”

Kanazawa’s perhaps controversial perspective is that of an evolutionary psychologist. “Men conduct scientific research (or do anything else) in order to attract women and get married (albeit unconsciously),” he says. “What’s the point of doing science (or anything else) if one is already married? Marriage (or, more accurately reproductive success, which men can usually attain only through marriage) is the goal; science or anything else men do is but a means. From my perspective, scientists are no different than anybody else; evolutionary psychology applies to all humans equally,” he adds.

Friendly Foxes

August 2, 2006  |  Evolution  |  5 Comments

I should be on a weekly schedule starting next week, perhaps with a long-delayed post on epigenetics. Until then, here’s something that I found fascinating.

The New York Times recently tracked the progress of Dmitri Belyaev’s epic fox domestication experiment. The result:

After 40 years of the experiment, and the breeding of 45,000 foxes, a group of animals had emerged that were as tame and as eager to please as a dog.

As Belyaev had predicted, other changes appeared along with the tameness, even though they had not been selected for. The tame silver foxes had begun to show white patches on their fur, floppy ears, rolled tails and smaller skulls.

One possibility is that a handful of genes — perhaps even just one — underlie all the changes seen in domestication. A structure in the embryo of all vertebrates, known as the neural crest, is the source of cells that constitute much of the face, skull and pigment cells, and many parts of the peripheral nervous system and endocrine system. If the genes in the neural crest cells were delayed just a little in coming into action, a whole range of tissues could be affected, including the maturation of the adrenal glands that underlies the first fear response of young animals.

There’s much more in the article and follow-up Q&A;, including some speculation on how similar domestication processes might have been involved in human evolution.

John Hawks raises a question about why domestication is possible at all, from the viewpoint of genetic variation:

The rats and foxes haven’t so much undergone genetic changes as simple enrichment of alleles that are already common. Which means that they may have unusual phenotypes as a result of these alleles being coincident at high frequencies, but those alleles already are doing something in normal, wild (and mostly solitary) animals. This doesn’t mean that the tame phenotype should already exist — even if all these alleles are independently common, if there are enough of them they may never all be present in any single wild individual.

So the interesting question is why these alleles that permit domestication in combination should already be common.

Domestication may involve multiple vectors, but a delay in the development of the neural crest appears to be a centrally important factor in this fox experiment. Now, given that humans have undergone some level of “self-domestication,” could we extend this result to humans? Could delaying the development of the neural crest in humans delay the whole maturation process, as is suggested by some parts of Baelyav’s fox results? And what might that mean for us today? Is there still significant genetic variation here- i.e. are some individuals or groups of people more “genetically domesticated” than others?

Mycomplete speculation here is that a high concentration of these genes selected for in domestication might result in a prolonged childhood and adolescence and lead to the existence of geeks (and perhaps a certain sort of intellectual in general). Geeks seem to hit their peak later in life and are often described as relatively non-aggressive, eager to please, late bloomers, lifelong learners, and even eternal kids (though they don’t seem to have floppy ears or rolled tails!).

Anyway, this story- and the research that comes from it- will be something worth watching.

Friday Links

June 30, 2006  |  Evolution  |  No Comments
  • Cochran et al. suggest that some illnesses or conditions that we currently think of as genetic or environmental may be primarily caused by germs. This idea is not new- we thought ulcers were caused by stress and lifestyle, but the culprit turned out to be bacteria– but the scope of Cochran’s research and claims, which include rheumatoid arthritis, MS, and schizophrenia, bears mentioning. His evidence includes recent findings and arguments from evolutionary fitness theory. An example from the article:

    Long-continued rheumatoid arthritis causes distinctive changes to the joints that can be recognized in Amerindian skeletons from the Mississippi valley going back several thousand years, but not in Old World skeletons from before ad 1500. This epidemiological footprint implicates an infectious agent that was brought back to Europe from the New World by early explorers [87].

  • Lord Martin Rees, the Royal Astronomer of Britain and all-around smart fellow, chats with Edge about the world’s prospects for the future and the dangers and hopes technology brings to the table.

  • Viva La Evolucion reviews a recent odd finding about DNA, that “genes with a greater proportion of third-position [amino acid] Gs or Cs are expressed more than genes with third-position As or Us.” The implications and importance of this are currently unknown.
  • Ars Technica gives some background on a Supreme Court case regarding how novel an idea must be for it to be patentable. Given the increasing economic and social importance of inventions and the increasing mess which is patent law, this could be the most important Supreme Court case currently on the docket.

In site news, I had people from every continent except Antarctica visit yesterday. Welcome, everyone.