My pedipalps were slavering at the news of a symposium on spider sex to be held on the Catalan coast of Spain. Ah, if only I had a legitimate excuse (other than prurience) and a budget that could handle the expense…
Here’s what seems to be a relatively simple problem in evolution. Within the Drosophila genus (and in diverse insects in general), species have evolved patterned spots on their wings, which seem to be important in species-specific courtship. Gompel et al. have been exploring in depth one particular problem, illustrated below: how did a spot-free ancestral fly species acquire that distinctive dark patch near the front tip of the wing in Drosophila biarmipes? Their answer involves dissecting the molecular regulators of pattern in the fly wing, doing comparative sequence analyses and identifying the specific stretches of DNA involved in turning on the pigment pattern, and testing their models experimentally by expressing novel gene constructs in different species of flies.
We biologists think we’re all grody and cool with our dead mice, but then some smart-aleck chemist has to go trump us all with thermite explosions. That just isn’t fair.
Just wait. Now some physicist is going to come along and make us all envious with his homebuilt laser.
Hold it! I just had a brilliant thought! If we got a physicist, a chemist, and a biologist together, we could make a laser-triggered thermite mouse trap. That would be waaaaaay better than a glue trap.
It’s a busy time for transitional fossil news—first they find a fishapod, and now we’ve got a Cretaceous snake with legs and a pelvis. One’s in the process of gaining legs, the other is in the early stages of losing them.
Najash rionegrina was discovered in a terrestrial fossil deposit in Argentina, which is important in the ongoing debate about whether snakes evolved from marine or terrestrial ancestors. The specimen isn’t entirely complete (but enough material is present to unambiguously identify it as a snake), consisting of a partial skull and a section of trunk. It has a sacrum! It has a pelvic girdle! It has hindlimbs, with femora, fibulae, and tibiae! It’s a definitive snake with legs, and it’s the oldest snake yet found.
Spot is quoting Kevin Phillips and his new book, American Theocracy(amzn/b&n/abe/pwll). He’s describing the stagnation of scientific progress in the West when religion set its heavy hand on learning.
Symptom number two [referring to attributes regimes that become increasingly theocratic], related to the first, involves the interplay of faith and science. What might be called the Roman disenlightenment has been well dissected in Charles Freeman’s The Closing of the Western Mind (2002). He dwells on how Rome’s fourth- and fifth-century Christian regimes closed famous libraries like the one in Alexandria, limited the availability of books, discarded the works of Aristotle and Ptolemy, and embraced the dismissal of Greek logicians set forth in the gospel of Paul [well, there is no gospel of Paul, but never mind]. To Freeman, the elevation of faith over logic stifled inquiry in the West- leaving the next advances to Arab mathematicians, doctors, and astronomers-and brought on intellectual stagnation.” It is hard,” he wrote, “to see how mathematics, science or associated disciplines that depended on empirical observations could have made any progress in this atmosphere.” From the last recorded astronomical observation in 475, “it would be over 1,000 years-with the publication of Copernicus’s De Revolutionibus in 1543-before these studies began to move ahead again.”
Keep that in mind while reading Orac’s discussion of creationists in medicine. It’s depressing that such an important and respected profession is overrun with shortsighted ignoramuses.
You can be an adequate doctor and be a creationist: you don’t need to understand evolution to follow your training and cut out a gall bladder or give an injection or diagnose a known disease. It just means that you will follow by rote the procedures of your predecessors. The practice will stay the same, but progress will stop. We will fall once again into the situation Phillips describes (although I suspect our successors will emerge from Farther Asia this time around.)
Orac talks about some of the reasons why it’s difficult to get doctors to be solidly and openly on the side of good science, but I think it’s essential for the prestige and future advancement of the medical profession that more of them think about correcting this failing in their training policies. Are they to be smart, flexible, adaptive, creative, and intellectual people striving to understand the workings of the human body, or is it enough to be a collection of technicians who know how to manipulate the tools of their trade? What makes a doctor different from a chiropractor if neither are to be rooted in good science?
What if you could pick one thing and start over from scratch? What would you change? Would you choose another career, a different home, a new spouse? Or would you choose to remake the world around you? Why not fix America’s prison system, make schools more efficient, or make your political leaders more intelligent?
The editors asked me to contribute to their special report, speculating on how we would “reinvent things without regard for cost, politics or practicality”. I thought a little bigger than a new spouse or career, though, and instead tossed in few peculiar ideas about reinventing humanity itself.
Susie Madrak talks about killing mice—read it for the denouement. I’ll share my first experience with killing mice, but I’ll keep it below the fold for the squeamish.
What is this phenomenon called “Science Blogging”? And when are you going to start?
Zenoferox has dug up a review of Crichton’s Andromeda Strain from 1969—Alexei Panshin tore into him for his bad science even then. I remember seeing the movie in junior high school myself, and feeling ripped off by the incredibly flaccid ending.
or•gan•ic | ôr’ganik | adjective. denoting a relation between elements of something such that they fit together harmoniously as necessary parts of a whole; characterized by continuous or natural development.
One of the wonderful things about how development works is that organisms function as wholes, and changes in one property trivially induce concordant changes in other properties. Tug on one element, changing it’s orientation or size, and during embryogenesis any adjacent elements make compensatory adjustments, so that the resultant form flows, fits, and looks organic. This isn’t that surprising a feature of development, though, unless you have the mistaken idea that the genome encodes a blueprint of morphology. It doesn’t; what it contains is a description of interacting agents that work together in a process to produce a complex result. Changes in genes and regulatory elements can essentially produce changes in rules of development, rather than crudely specifying blocks of morphology.
What does this mean for evolution? It means that subtle changes to the rules of development can be caused by small changes to genes (and especially, to regulatory regions of genes), and that the resulting morphological changes may be dramatic, but are still integrated organically into the form of the organism as a whole. Our understanding of how development works is making it clear that large scale macroevolutionary change may be much easier than we had thought.
Here’s an example where this insight is clarifying the evolution of an organism: the fossil record of bats shows an abrupt appearance of fairly sophisticated creatures with elongated digits, clearly capable of gliding or powered flight, with no known intermediates. We expect there were less fully flight-ready predecessors, but fossil preservation is not kind to small, delicate boned animals. It’s also possible that the transitional period was fairly brief; it looks like turning a paw into a long-fingered membranous wing may be a fairly simple change on a molecular level.
