Front-Loaded Evolution
From SkepticWiki
[edit] Definition
Front-loaded evolution is the hypothesis that the genetic information required to produce all living species from a few forms or one was "front-loaded" into the first organism or organisms, and that the process of evolution has been the result of the successive activation of some of these genes and loss of others.
[edit] Discussion
The reader will notice that although, in this view, the first organisms might have been morphologically simple, they would have to have been genetically complex. As such, this method of evolution appeals to those who wish to reconcile the facts of evolution, especially as revealed by paleontology, with their intuition that the complexity of natural productions requires Intelligent Design.
The idea is not, on the face of it, a stupid one. We have no difficulty, after all, in believing that a single cell can develop, by way of a tadpole, into a frog, in a manner predetermined by the genetics of the organism; why then should there not be a similar process of phylogenesis? Moreover, such a process might serve as an explanation for the changes seen in the fossil record, since front-loaded evolution, with this initial form designed by a sufficiently intelligent and foresightful designer would look quite a lot like evolution by natural selection.
The hypothesis was only really falsified with the discovery of the nitty-gritty details of genetics. The problem is this: an unexpressed gene is subject to mutation, but it is not subject to natural selection. There would be nothing to prevent the accumulation of harmful mutations in any front-loaded gene still awaiting the epoch in which it would become useful: over millions of years, the chances against a functioning copy of such a front-loaded gene surviving the processes of mutation and genetic drift are astronomical.
Moreover, the existence of beneficial mutations shows conclusively that organisms are perfectly capable of evolving new functions without any front-loading of the genetic information. So not only is front-loaded evolution impossible, it is also unnecessary.
To summarise, although the idea of front-loaded evolution was not initially a stupid one, modern knowledge of genetics has robbed it of all scientific credibility: which does not, of course, prevent modern-day fans of Intelligent Design from touting it as an alternative to the Theory of Evolution.
For another historical example of a hypothesis as to the mechanism of evolution which didn't quite cut it, the reader may be interested in our article on Lamarckism.
