REAL GENES, REAL INTELLIGENCE 125text. Genes are very much the followers, not the leaders in the decision
making.
Furthermore, trying to account for variation, even at this level, by de-
ciding what is ge ne tic and what is environmental is already quite impos-
sible. Environmental structures regulate gene transcription, and every
gene transcript becomes the environment of other genes. Th e resolution
of those in cell responses then changes the external environment with
feedback consequences, and so on. It is those dynamic patterns rather
than their ele ments that are impor tant.
Th e importance of structure over ele ments is shown in another way.
TFs are crucial gene products and gene regulators. But they vary in form
only very slightly from fl ies to mice to humans: “a striking level of con-
servation, despite dramatic morphological diff erences resulting from
more than 600 million years of evolution.”^18 Yet we get tremendously
increased phenotypic variation. Th is is because the form and variation of
cells, what they produce, whether to grow, to move, or what kind of cell
to become, is under the control of a whole dynamic system, not the genes.
GENE PRODUCTS BECOME FURTHER MODIFIEDWhat we have just glimpsed is the way that a cell picks up statistical
patterns in the storm of signals from its environment and how these are
assimilated by internal pro cesses. Th e implications of the signals are then
meshed with internal conditions and needs. Th e whole ensemble then re-
cruits transcription factors to call up appropriate gene products to create
a harmonious response. Already this is more like an orchestra than a
knee- jerk reaction, producing a diversity of harmonies as required by
changing conditions.
However, what I have discussed so far is by no means the limit of such
variation production. It turns out that, under the system dynamics, the
transcripts— the gene products— are themselves subject to further exten-
sive modifi cations. Th is further editing of gene products is now a vast
area of research— one that increasingly rejects the notion of direct cor-
relation between ge ne tic variation and phenotypic variation. But here
I can only off er a brief summary of fi ndings.
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