Friday, July 31, 2009

Like most places in the northeastern US, Vermont has been having a very wet summer. It rains most days, and the ground rarely has time to dry out before the next rain. This is just how the slugs like it. They seem to be everywhere, doing all their usual sluggy things: eating leaves, devouring mushrooms, sitting on wet rocks, getting squished on the sidewalk. What else is there for slugs to do? This afternoon I saw a group of slugs doing something I've never seen slugs do, or even heard of them doing.

Yesterday, a couple of blocks from home, I passed a freshly roadkilled squirrel. By today, most of the carcass was gone, with only bits and chunks scattered on the shoulder. And on each little morsel sat a garden variety slug, chowing down. The bigger chunks had two or three slugs, each about an inch long, actively feeding (or at least that's what it looked like, it was hard to know for sure, as their mouthparts are underneath). There were a few slugs that had been run over as they fed, and others had come in to finish the job, and eat there recently departed kin.

I've watched slugs eat hundred of times, and it has always been on plant matter or fungi. It never occurred to me that they might eat meat. So of course I checked what Wikipedia had to say on the subject:

"Many species of slugs play an important role in ecosystems by eating dead leaves, fungus, and decaying vegetable material. Other species eat parts of living plants.
Some slugs are predators, eating other slugs and snails, or earthworms.
Most slugs will on occasion also eat carrion, including dead of their own kind."

Which makes me wonder if there was ever a B movie about giant radioactive predatory slugs.

Saturday, July 25, 2009

God's bellybutton

Hubble Space Telescope finally answers that question about whether God has a navel.

NASA now planning to aim telescope slightly lower.

Monday, July 20, 2009

Ego boost of science.

There is a very flattering article in tomorrow's New York Times science section, by Natalie Angier, about our article on the definition of behavior. (There is also an online quiz associated with it.) It has, to be honest, many fewer errors than I generally expect from science journalism. The main one that will jump out at most of my peers is her statement that, "neither that textbook nor any other reference he consulted bothered to" define behavior precisely. We found lots of definitions, they just didn't agree with each other, or with what we or other biologists thought the word meant. That said, I think this NYTimes article is much better than most science reporting on the accuracy front. And of course, it is nice to have one's work described as "provocative and crisply written" in a large circulation newspaper.

She did neglect mention my two favorite things about the article; the title is, "Behavioral biologists do not agree on what constitutes behavior," and; in a biological article in a peer reviewed journal, we quote both Supreme Court Justice Potter Stewart's opinion on pornography and Conan-Doyle's Sherlock Holmes mystery of the dog that did nothing in the nighttime. I amuse myself heartily.

Saturday, July 18, 2009

Studies in current evolution

Research Question:
To what extent is the number of children people choose to have in developed nations heritable (in the genetic sense)?

If it is heritable, this is most likely the largest determiner of fitness outcomes, as the great majority of children survive to adulthood, no matter how many siblings they have. This implies potentially rapid Darwinian selection for those who choose larger families. Over the course of a few centuries this selection could have important impacts on human demography and population. Given an estimate of heritability, this effect could be quantified.

The old twins/siblings separated at birth databases?

Ethical considerations: many

Likelihood I will actually get around to this:

Thursday, July 16, 2009

Long Term Prediction

Several thousand years from now, if there are still humans around, someone will look back and describe the last few thousand years as a time of extraordinarily rapid biological evolution for humanity.

Wednesday, July 15, 2009

A bit humbling

I pride myself in knowing something about a very wide range of topics, even if there are very few in which I could confidently call myself expert. I can converse intelligently on most topics in organismal and population biology, and have read bits and pieces in a large range of other fields. I like to tell myself that this will allow me to make important scientific advances, because I can draw together knowledge from disparate fields. But then when I compare my own writings on the co-evolution of longevity and the brain in primates (the paper I am currently working on) to this amazing detailed, readable and reasonable chapter:

Kaplan H, Gangestad S, Gurven M, Lancaster J, Mueller T, and Robson A. 2007. The evolution of diet, brain and life history among primates and humans. In: Roebroeks JWM, editor. Guts and brains: An integrative approach to the hominin record: Leiden University Press. p 47-81.

The various authors of this paper have each been working on a set of related questions for decades, and they bring together this acquired knowledge into a devastatingly clear and cogent argument. Where I have vague intentions to explore an idea, they have specific arguments and evidence to back them up. I can't help but feel a bit like a child building a pile of sand on top of the great pyramid, thinking I am making it taller when I'm just making a mess. Or maybe it is just past my bedtime.

Angst of science.

I get this terrible sinking feeling when I discover an error in my calculations, because it means there are probably more, and I might have to do a lot of analysis and writing over again, and frankly checking calculations for errors often takes longer than just doing it over. When I shortly thereafter discover that my original math was correct, and I was just having a brain fart, this does not greatly improve my confidence in my other calculations, so I go through and recheck everything else I've done. But part way through that, I realize there would have been a much more convincing way to design the analyses, so I do that, which takes all of today.

Saturday, July 11, 2009

Hiking the Montshire

We're in Norwich VT for the summer, while I finish writing my thesis, and before we head off the Germany. Yesterday, the first rainless day since we got to VT, I headed to the Montshire Museum of Science, a mile out of town, to check out their system of trails. The price of admission ($10 for adults) to this cool little child-oriented hands-on science museum got me a map of their trails and permission to walk them. The map shows 0.4 miles of trail here and 1.2 miles there. Doing some addition I decided that an out-of shape scientist could walk all their trails in one afternoon, and set out to do so. The forests around the museum are fairly typical second growth northeastern forest, with a mix of hardwoods and softwoods. Nothing spectacular, but extremely pleasant to walk though on a hot bright afternoon.

The trails are well maintained and marked, and most are flat enough for strollers, although I met almost no other hikers once I was away from the main museum building. They follow the banks of the upper Connecticut river or follow low rambling ridge-lines. Sprinkled along many of the trails are scientific activities and displays. It was fun to stop at the solar-powered kiosk and push buttons to hear recordings of the local birds. When I pushed the button to hear the Black-throated Blue Warbler, a real BTBW responded from the trees overhead. Their scale model of the solar system is stretched out along one trail, with Pluto about two miles from the sun.

Behind the museum is a stream-fed water park/ science display packed with wet excited children learning about waves and currents. Inside the museum is a relatively quiet pandemonium of children running, watching, pulling, stretching and learning the word 'viscosity.' My cousins, three and five years old, incessantly demand to visit the Montshire, and everything seems to be well aimed at kids their age. None of it is profound, but all is well presented and designed to keep kids engaged and learning.

I went about 8 miles (including the road to and from Norwich) in a little over three hours of actual walking, and can now say I have hiked every trail the Montshire has. It is flat, short and simple enough to have made a great first hike for an old naturalist trying to get back into shape. Next I will try part of the Appalachian Trail, which comes right through Norwich. But first I will lay down and rest my aching muscles.

Thursday, July 09, 2009

EvoDemo Poetry

A chimpess keeps the knack to breed
until she's not alive
But woman stops and then goes on
another forty-five

A hydra grows and buds and splits,
then does it all again
But man can live his life but once
before his certain end

A rotifer skips infanthood,
lays eggs on her first day
But humans grow and learn and find
all reasons for delay

You'll live your life as humans do
and never think it's odd
But redwoods still are saplings
when we're pushing up the sod.

Tuesday, July 07, 2009

H1: The universe is 96% aliens.

Most good scientists are deeply impressed by, and even excited about, how little we yet know, how much there still is to find out. Our science and technology are impressive accomplishments, but still very much in their infancy as compared to what is possible.

Imagine, if you will, a tremendously technologically advanced civilization, whose technology just continues to advance. What is the end point? What do they and their technology look like after billions of years of rapid technological advance? I think it is safe to say that we don't know. It clearly wouldn't be anything that we currently have the science or technology to understand. As Arthur C. Clarke wrote, "Any sufficiently advanced technology is indistinguishable from magic." We wouldn't understand this alien technology or what it did any more than Cro-Magnons would understand a wireless modem. This hyper-advanced civilization would presumably have explored ever nook, cranny and loophole in the physical laws that govern the universe and transformed their technology and themselves beyond recognition. We likely wouldn't even recognize it or them as technology or life. We might not even recognize them or their technology as normal matter or energy, although after billions of years they would likely have transformed large parts of the universe itself.

Which brings me back to how little we currently know. Modern cosmology assigns only 4% of the mass/energy in the universe to "normal" matter, the kind we know anything about. 22% is thought to be "dark matter" and the remainder, 74%, is "dark energy." We know little about dark matter and next to nothing about dark energy, except that they are necessary to make our equations work out. Putting to one side the plausibility that the equations are wrong, we are free to speculate on what is going on with that other 96% that we can't see but suspect is there. My preferred hypothesis is that the universe is 96% aliens. Which is a somewhat silly way of saying that other life-forms may have transformed some large portion of the mass and energy in the universe into forms we don't understand. Why should a civilization with the most advanced technology we can pretend to conceive of be expected to leave things as they found them? If conservation of mass/energy is one of the rules they can't get around, couldn't a big crowded universe of aliens be expected to convert a large portion of its limiting resource into whatever form allows them to use this resource most efficiently? Dark matter releases no detectable radiation, and as such leaks no mass/energy. This would also help to explain why SETI can't detect any aliens. A civilization that hoards mass and energy isn't going to go blaring electromagnetism all over the place.

Why under this hypothesis would 4% of the matter be left as boring old stars, dust, black holes and light? Perhaps these things serve some function for the dark aliens. Or maybe we, and everything we can see, are a designated nature preserve with strictly enforced limits on poaching. To try to answer this last question is to move from pure speculation to pure fancy, so your guess is as good as mine.