Candidates Vie for Stupid Evolution Quote of the Week

Contributions for the weekly prize sometimes come in as numerous as contestants at the Boston Marathon.  You can send in your contributions or vote on the following:

• Evolution as sculptor:  Sid Perkins, in Science News, submitted three entries in an article on penguin evolution:
  • Early in penguin evolution, the bones, especially in the wings and hind limbs, became thick and dense.  This change would have improved the ease with which the birds could dive to chase underwater prey.  In contrast, the bones of flight-capable birds are highly buoyant because evolution has fine-tuned them to be thin, light, and, in some cases, filled with air.
  • Besides acquiring dense bones, penguin ancestors evolved narrow wings with inflexible elbows that worked as streamlined hydrofoils….
  • Evolution Marches On…  So, even though penguins have been immensely successful, the forces of evolution continue to sculpt their genome.
• No speculations here:  Thurston Lacalli, in Nature (Nov 25), in an article on the evolution of the eye, commenting on a presumed ancestral marine worm that had two kinds of photoreceptors:
  

  Speculations aside, the new work provides a solid starting point for further study of the evolution of photoreceptor organs during the diversification of bilateral multicelled animals.  In evolutionary terms, it is a long way from a simple ocellus [see 08/13/2004 headline], involving no more than a few cells, to the complexity of an optimally constructed image-forming eye.  Evolution seems to have accomplished this transition piecemeal, by myriad small steps, each an adaptive improvement over what went before.  A detailed accounting of the steps is as yet beyond us, but clarifying the nature of the ancestral condition is a useful beginning.

• The persistence of myth:  Paul Mellars, in Nature (25 Nov) in an article on Neanderthal man (see also 10/01/2004 and 09/21/2004 headlines):
  

  That the Neanderthals were replaced by populations that had evolved biologically, and no doubt behaviourally, in the very different environments of southern Africa makes the rapid demise of the Neanderthals even more remarkable, and forces us to ask what other cultural or cognitive developments may have made this replacement possible…. Perhaps it was the emergence of more complex language [see 02/27/2004 headline] and other forms of symbolic communication that gave the crucial adaptive advantage to fully modern populations and led to their subsequent dispersal across Asia and Europe and the demise of the European Neanderthals.  The precise mechanisms and timing of this dramatic population dispersal from southern Africa to the rest of the world remains to be investigated.

• No data?  No problem:  R. Van Boekel et al., in Nature (25 Nov), in the abstract to a paper on interplanetary dust:
  

  Our Solar System was formed from a cloud of gas and dust…. Little is known about the evolution of the dust that forms Earth-like planets. (Note: All they suggested was that observations from dust disks around other stars shows an apparent zone of crystallization in the inner regions: “Our observations thus imply that crystallization of almost the entire inner disk and a substantial part of the outer disk must have occurred very early in the evolution of the disk.”  How the crystals afterward survived the melting of terrestrial planets during their formation and bombardment was not explained.)

  • Giving evolution a kickstart:  Robert Service, in Science (26 Nov), commenting on recent experiments on artificial selection of proteins:
    

    Evolution isn’t known for its quick work.  In recent years, researchers have come up with numerous ways to give it a kick in order to evolve [sic; this is intelligent design] proteins with new functions.  But most of these techniques are painfully slow, taking as long as a month to go through a single round of evolution.  The immune cells of vertebrates long ago perfected a faster approach, which they use to generate the myriad antibody proteins that fight off infections.  Now a team of California researchers has coaxed immune cells to apply their skill to other proteins, an ability that could speed the development of novel proteins for studies from catalysis to cell biology.

  • Comfort is the mother of evolution:  Erik Stokstad, in a story on horse evolution in Science (26 Nov):
    

    High-crowned teeth took a while to evolve to resist gritty food.  Later, During the Miocene, horses and camels were evolving longer limbs, but apparently not to escape accelerating predators–which evolved longer limbs some 20 million years later.  Instead, [Christine] Janis (Brown U.) proposed, the limbs first evolved to be more efficient at walking…. High-crowned teeth might not be the only way to make life on the grasslands less of a grind.

  Decisions, decisions.  It’s like having 800 cable channels and nothing worth watching except the old comedies.