When I was a grad student, I got an advertising flyer in the mail with the tantalizing blurb:

Minimal Human Contact . . .
. . . and free T-Shirts

It went on to say that they knew why I decided to pursue a career in the life sciences: I wanted minimal human contact, and I wanted to score a free T-shirt once in a while.

They offered to give me a T-shirt if I would fill out a survey on their web site (of course, I couldn't resist). They definitely understood where I was coming from.

It's funny. I've seen similar pictures of countermeasures making "angels". These were, of course, cited as "evidence" of the Divine Favor afforded our military forces.

There are times when I have been told that I would lose my head if it were not firmly attached, but I never went to Tchaikovsky's lengths to keep it on.

OK, so the ancient Egyptians removed the brain of dead people through the nose as part of mummification. Now we're removing appendicies through the mouth.

Maybe not much has changed, although I don't really think we'll be seeing brain surgery through the nose anytime soon.

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Or maybe we will!

I once saw a poster at a university promoting carpooling. The poster encouraged participation in a carpool one day a week. The hook was basically that it was the right thing to do.

I was not convinced by this poster. After some thought, I decided that any serious effort to promote carpooling should include a compelling and valuable perk. For instance, at this university people were always complaining about the shortage of parking spaces. If I were to be convinced to join a carpool, I would want a special carpool parking permit that would let my carpool park close to the main campus.

Some months later, I read an editorial in a local newspaper about how few of the university's students seemed to be pursuing a rigorous education. I submitted a letter, somewhat tongue-in-cheek, criticizing the rather unimpressive recognition given to our top students. I suggested that top-notch students taking demanding courses should be awarded a special "black" parking sticker that would entitle them to access to any parking lot on campus, including faculty/staff parking. I as surprised to see the letter published in the next issue.

The insulin-like growth factor-1 is a growth hormone whose fetal form is encoded by a gene with a rather interesting regulation. It is paired with a "receptor" protein that binds to the hormone on fetal and embryonic cells. Normally, a growth hormone-receptor pair works by the hormone activating the receptor, triggering a series of actions resulting in the initiation of cell division and growth.

During embryonic development, IGF-1 has two receptors. One will result in cell growth, while the other seems to bind to IGF-1 without effect. This false receptor is encoded by a gene that is indistinguishable from a sugar binding protein. When the IGF-1 gene is inherited from the father, it is active and produces growth hormone. When the IGF-1 gene is inherited from the mother, it is inactivated. Conversely, when the false receptor is inherited from the father, it is inactive, while the maternally-inherited gene is active.

So?

It can be considered that larger offspring serve the interests of the father, who wants his offspring to be stronger and better adapted to survive. On the other hand, the maternal agenda would be to have more moderately sized offspring that will not be so risky to carry and birth. So, paternally activated growth hormone is countered by maternally activated false growth hormone receptors.

This kind of gene regulation is called "genomic imprinting". It is a strategy used on a number of different genes for different apparent purposes. This particular example is sometimes seen as a 'battle of the sexes', but is illustrative of the forces that can shape the evolution of gene expression strategies.

See this article on the evolution of genomic imprinting at PubMed. PubMed is a repository of research articles at the National Library of Medicine, and access to many of these articles is free (your tax dollars at work).

If one can postulate an earlier, more generic form of the toxoplasma parasite, it may be seen as one whose natural habitat inside the host is the brain. Such parasites need to get to their habitat by circulating through the bloodstream, but they can settle in their favored location by attaching preferentially to molecules that are characteristic of particular organs. (This is known to work for the cold viruses, for cholera, for toxic E. coli).

Understandably, having parasites in one's brain will make the host sluggish or erratic in its behavior. Such deficiencies would make those hosts more prone to be caught and eaten by predators (It is well accepted that predators primarily catch the weak and ill).

As is the case with most living things, any population of individuals will have some variation in their makeup. Some will be more preferential to colonize particular parts of the brain. Some will be more generalist, and colonize the entire brain. (Such variation of individuals within a population is seen every day. Your office or classroom is filled with humans, but not filled with identical humans.) These variations are often inherited and are also subject to mutation.

A mouse that is infected with a toxoplasma that infects its entire brain may act so erratically that its ability to avoid predators is impaired before the colonies of parasites have had a chance to mature. A cat that eats such a mouse may not pick up enough parasites to become sustainably infected (The need for a minimum infectious load is well known in infectious disease studies).

A mouse infected with a more picky toxoplasma might take longer to develop such impairments. Perhaps such parasites are of a variant that colonize parts of the brain that are not directly involved in motor control (so the mouse doesn't stagger about), but are involved in less important controls (such as response to certain smells). When the infection becomes great enough, the mouse will begin to stagger about, and will be caught by a cat. The cat will now receive a parasite population of viable size.

Within the population of toxoplasma that infect non-critical parts of the brain, there may emerge varieties that have other preferences in other brain regions that are distinguished by their unique chemical markers. Among these would be a population whose infection makes mice less able to respond appropriately to indicators of danger. These risk-taking mice may be the ones we see today.

So, how does this relate to sex kitten humans? Promiscuous behavior in females and aggressive behavior in males may be two sides of the same coin of risky behavior patterns. Males and females with the same types of brain damage may express this in the form of different kinds of behavior.

So, the foundations of evolutionary theory are: A population has within itself a wide range of heritable variations. Some of these variations may confer a reproductive advantage over the rest of the population. Under conditions of relatively scarce resources, such advantages will result in the more advantageous variants becoming more prevalent with in the population. Further variation within this population will lead to refinement of the relevant trait.

Science is hard work, and not a game for quitters. Even a highly simplified speculation on the evolution of this trait takes a lot of words to describe. Each of the steps is known to us as a result of decades of research by thousands of full-time scientists, and to fully appreciate the smaller details may require a lifetime's dedication to study. It is not something summed up in a sarchastic one-liner.

Parasite 'turns women into sex kittens',/a.

"A COMMON parasite can increase a women's attractiveness to the opposite sex but also make men more stupid, an Australian researcher says."

Hmm . . . this would make a nice video instructable.

Jim Hensen always seemed to be a kind and childlike soul. It was a great loss when he died.

It's strange to look at this picture. It rather reminds me of a Life magazine photo of Adolf Hitler gazing fondly at a little boy in his brownshirt uniform.

KK Bill's father must have been so proud when he first dressed him in this Klan getup. He was seeing his core values being passed on to the next generation, and maybe the faint glimmer of a bright future.

It is ghastly to see this here and now, but the picture and card are a reflection of an entire culture with its cherished values and standards of right and wrong. When one group rails against the "Teen Mania - Acquire the Fire" rally for "radical Christian Youth" and another points with fear and alarm at the "Burning Man Festival", we should see that these are really two sides of the same coin.

My concern is that terrorists may use this technique to train goldfish to deliver bio-weapons to critical water supply points in the U.S.

Something's got to be done!

It's amusing to read the disparaging remark by Denita TwoDragons, describing the alteration as a "'shop job". At the time, photographic alteration was not done by digital manipulation, but by X-acto knife, airbrush and darkroom tricks. While the fencepost removal is not even as smooth as contemporary methods could produce, such manipulation was not a trivial matter of a few mouse clicks.

I always "roll my own". I heard about this device some years ago, and now I use my fingers to "tickle" a can into rolling on its long axis in a bed of ice water.

Wasabi? That's nothing compared with South Korea's plan to put kimchi on the space station. Between its own natural pressurization from fermenting cabbage (an explosion risk in the low atmospheric pressure within the station), the terrible-yet-strangely-appealing smell of the food itself, and the extended flatulence that follows eating it, kimchi aboard the station should be considered an act of terrorism!

When I saw this, I expected to see a tribe of ape-men around it, to the opening bars of Also Sprach Zarathustra.