A new amazing strategy has been discovered to add to the list of defenses plants use against herbivores. It has long been known, for instance, that plants detect the secretions from caterpillars and respond with toxins and chemicals that slow the caterpillars' digestion. Now a new defensive strategy has been discovered: the altering of the flowering time. This has been observed in a tobacco plant which produces new morning-opening flowers when attacked by larvae of the hawkmoth pollinator.Normally the plant releases benzyl acetone to attract the hawkmoth pollinators and produces flowers that open at night when the hawkmoth is active. But the morning flowers, produced in response to hawkmoth larvae attack, produce less benzyl acetone and are pollinated by hummingbirds which are active during the day.
With evolution we must believe that this dramatic change in flower phenology, as well as the other plant defenses, just happened to arise so they later could be selected. A mutation occurred that just happened to activate a benzyl acetone release mechanism, which just happened to attract the hawkmoth pollinator. And another mutation just happened to design a system that detects caterpillar secretions. Then another mutation just happened to couple with the detection system to produce and release chemicals, to slow the caterpillar digestion, as well as toxins. Then another mutation just happened to create the system to switch the flower design so it opens in the morning.
And of course these designs are observed by us only because they were the evolutionary winners. They are the proverbial tip of the iceberg. For every winner there are untold myriad losers. The designs that produced some other chemical rather than benzyl acetone. The designs that detected chemicals that the caterpillars don't secret. The designs that didn't couple with the detection system. The designs that produced secretions that had no effect on the caterpillars. The designs that wreaked havoc on the flowering process rather than merely altering the flowering time. And so on, and so forth. The plant must have been a veritable idea factory, churning out all manner of mostly useless Rube Goldberg devices.
This, for what it's worth, is evolutionary theory. A game of fact-free story telling all funded by the taxpayer. Religion drives science, and it matters.
"With evolution we must believe that this dramatic change in flower phenology, as well as the other plant defenses, just happened to arise so they later could be selected."
ReplyDeleteAbsolutely not true. You are insisting that evolution claims that nature leaps up the face of mount improbably in a single bound. It does not. That is kinda the point of the mount improbable metaphor. Great feats are reached - but through the build-up of small steps heading in the same direction.
You are effectively claiming that this mechanism is irreducibly complex. Do you have any reason to suppose this?
For someone so sensitive to others using strawman arguments, you really do have a grotesquely distorted view of the theory of evolution.
Ritchie's post might have more traction if there were any fullsome example (i.e., set out the consecutive DNA changes) of a new structure created by random changes to DNA, each of which had a beneficial effect significant enough to positively affect rates of reproduction of animals with that DNA mutation as compared to ones without it.
ReplyDeleteNo such example exists.
Moreover, the current mechanisms and probabilities involved make it impossible that such an example could ever exist.
regards,
#John
#John1453: No such example exists.
ReplyDeleteA well-established example is the evolution of the mammalian middle ear. Each step in the process can be shown to be within the range of normally observed heritable variation, as well as a selectable benefit to the organism. And the final structure is irreducibly complex.
@Zachriel, "A well-established example is the evolution of the mammalian middle ear. Each step in the process can be shown to be within the range of normally observed heritable variation, as well as a selectable benefit to the organism."
ReplyDeleteThat's quite a claim. Can you give a reference? The stuff I find on evolution of the mammalian inner ear is full of "may haves", "probablys", "could haves", and multiple homeoplasies (i.e. convergent evolution). Wikipedia says that new fossils "suggest that it was not a simple linear process", which sounds suspiciously like a euphemism for "we have a hard time fitting all these fossils into a single consistent framework." And that suspicion is borne out as you read about Yanoconodon's contradictory signals of being an ancestor of monotremes or of placentals and marsupials.
The only selectable benefit mentioned regarding the ear bone differences is a (presumed) improvement in hearing higher frequencies. It is not explained how this benefit accrued at every one of the many steps required, without requiring any steps that reduced hearing, knocked it out completely, or were neutral.
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ReplyDeletetest