Field of Science

Symbolic Representation is the Key to Major Evolutionary Transitions?

I'm briefly coming up from the sea of thesis preparation (two weeks until defense!) to share this truly remarkable quote I just read:

Consider the following: in the evolutionary course there
have been a few great junctures, times of major evolutionary
advance. Their hallmark is the emergence of vast, qualitatively
new fields of evolutionary potential, and symbolic representation
tends to underlie such evolutionary eruptions. These "New
Worlds" can arise when some existing biological entity (system)
gains the capacity to represent itself (what it is and/or does) in
some symbolic form. The resulting world of symbols then
becomes a vast and qualitatively new phase space for evolution
to explore and expand. The invention of human language is one
such juncture. It has set Homo sapiens entirely apart from its
(otherwise very close) primate relatives and is bringing forth a
new level of biological organization. The most important of these
junctures, however, was the development of translation, whereby
nucleic acid sequences became symbolically representable in an
amino acid "language," and an ancient "RNA-world" gave way
to one dominated by protein.

-from Carl R. Woese, "On the Evolution of Cells", PNAS, 2002.

Gene-culture Co-evolution

A while ago, I wrote on the hypothesis that humans have essentially stopped evolving genetically, because of our cultural emphasis on keeping all humans alive, no matter how disadvantaged.

The New York Times reports today on the opposite idea: that human culture may actually intensify the selective pressure on our genes. This idea is known as gene-culture co-evolution, since although our genes and our culture evolve through separate processes (biological reproduction vs. sharing of ideas), these two processes interact and affect each other.

The Times article surveys how culturally evolved changes in diet, lifestyle, and social norms could have influenced the genetic evolution of our digestive systems and brains. But as a discussion starter, I'm interested in more speculative questions: is our evolving culture still shaping our genetic evolution? If so, in which directions are we being pushed?