9 Conclusion
There are two great facts about life that shed a new light on the mechanisms of evolution. The first is that genes and proteins are produced by copying and coding, by transcription and translation, i.e. by two fundamentally different mechanisms. The second is that natural selection is the long-term result of copying, i.e. of only one of those two basic mechanisms. This implies that coding is a distinct mechanism of molecular change and, in the long run, a distinct mechanism of evolutionary change. The difference between the two mechanisms, furthermore, is not limited to genes and proteins, and we find it at all the other levels of organization. It is the difference that exists between heredity and metabolism, between genetics and development, between individual change and collective change, between information and meaning.
Embryologists have traditionally maintained that development is a novelty-generating mechanism in its own rights, but now the time has come to qualify this long standing claim and turn it into a testable proposition. The solution proposed here is that the novelty-generating property of development comes from specific codes of development and is distinct from natural selection because coding is distinct from copying.
It may be pointed out that embryonic development has been explained by the genes of development without invoking any codes of development, so what is the point of such codes? The point can perhaps be illustrated by a comparison with protein synthesis. It is certainly true that there are genes for all the molecules of protein synthesis, but could we really explain that process without the genetic code? The genes of translation do not make the code of translation redundant, and the same is true for the genes of all the other codes.
We realize in this way that there is more to development than the genes of development. The great challenge is precisely the codes of development because they are the whole of which the genes are a part. We simply cannot study life without studying its codes, and we cannot understand evolution if we do not realize that it has been shaped by natural selection and by natural conventions with largely complementary roles: natural conventions account for the great novelties of the history of life whereas natural selection explains the gradual transformations that adapted those novelties to the real world and allowed them to survive.
The long-standing claim of embryology has been that development cannot be explained by natural selection alone, but now the time has come to generalize it. It is the whole of life that cannot be explained by natural selection alone because there have been natural conventions in all steps and stages of evolution, from the first cells all the way up to embryos and then to brains, minds, and finally consciousness.
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