Saturday, November 12, 2011

Sticking Around For a Few Billion Years
I was going in the security door at work, and noticed something strange on the brick edge of the door frame. It looked like a twig, but on closer examination, the stick appeared to have two legs.  It was a “stick insect” or Phasmatodea, according to Wikipedia.  The second picture is a close up of its eyes, which are very small and oddly situated in the middle of its body.
Evolution is a difficult to get one’s mind around.  Here’s a life form that is a credible imitation of a tree part.  How did it get to be what it is, and what did it evolve from, and through, to get to where it is?

Is it the luxury of more than enough time? That would be 4.5 billion years, if the stick creature started at the very beginning.  Not likely, but, give or take a billion years, that is still a long time.  In our own timeline (that is “humans” so far) we see changes, attributable to evolution (not all agree on this).  My only problem with the word is that it implies getting somewhere, when the sole point of evolution is just another generation of survivors.  The point so far, is survival, at least on the surface.

By the way, Phasmatodea are not inclined to reproduce in the manner that humans do. The population is mostly female, and they don’t need a male to produce offspring.  Females  can lay eggs that hatch to become females with the same genetics as the mother.  If they can find a male, they can, after finding a private spot, mate. Even then, the likelihood of a male offspring is less than the likelihood of a female, although this is the only way that genetic variation can occur.

    If that is not enough puzzling detail, there is the “egg promotional process.” Some Phasmatodea have eggs that look like a type of food commonly gathered by ants (thanking Wikipedia here!). Ants carry the eggs (which look remarkably like the ant's eggs) to their nest.  The young nymph that hatches from the egg looks exactly like an ant. This nymph climbs to safety in a plant or tree and then develops the features of an adult Phasmatodea.

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