2 Responses to “Front-Loading Predicts Preadaptation”

1. Zachriel Says:
   September 9th, 2008 at 6:46 am

   Argument by semantics.

   Mike Gene: The reason I mention this is because the term ‘exaptation’ appears to be a non-teleological reframe for phenomena previously catergorized as something that had telic resonance – ‘preadaptations.’

   The concept of exaptation goes back to Darwin, 1859.

   Origin of Species: The illustration of the swimbladder in fishes is a good one, because it shows us clearly the highly important fact that an organ originally constructed for one purpose, namely flotation, may be converted into one for a wholly different purpose, namely respiration. The swimbladder has, also, been worked in as an accessory to the auditory organs of certain fish, or, for I do not know which view is now generally held, a part of the auditory apparatus has been worked in as a complement to the swimbladder. All physiologists admit that the swimbladder is homologous, or 'ideally similar,' in position and structure with the lungs of the higher vertebrate animals: hence there seems to me to be no great difficulty in believing that natural selection has actually converted a swimbladder into a lung, or organ used exclusively for respiration.

   There's nothing telic about it. New words are often coined in science to avoid confusion.

   Mike Gene: front-loading predicts preadaptation

   Well, that's a specific scientific claim. And vacuous. The Theory of Evolution predicts that adaptive structures evolved through selection. That means any "preadaptation" must have also evolved through selection. This is a testable hypothesis. Front-loading is an extraneous entity.

Comment by Zachriel — September 9, 2008 @ 6:46 am

2. The Pixie Again Says:
   September 9th, 2008 at 11:15 am

   So genes are preserved if they have some function. In "Front-loading vs. Exaptation?" Mike seems to be making the claim that this offers the front-loading scientist a way to ensure the important genes will survive until they are needed. The gene for nerves that is also found in sponges has been posited as an example of this by Bradford (if I understand his intent). However, sponges split from the rest of the animals something like 500 to 600 million years ago; life started perhaps 4 billion years ago. The front-loading hypothesis requires that this gene was in place – and presumably had some function – for well over three billion years before it got used in animals. Is that plausible? What function did it have in single-celled organisms?

   Not quite on topic, but I would be interested to hear an estimate of how many genes where front-loaded into that first cell. Were they only genes that would be useful for mankind? And perhaps less on topic; were eyes front-loaded, and if so, how come there is such a diversity.

Comment by The Pixie Again — September 9, 2008 @ 11:15 am