default blog post image

Evolution: It’s Humanly Possible

When discussion turns to the rapid evolution of resistance in response to toxic chemicals, inevitably someone has to ask, “So, what about us? Can we evolve our way out of this mess?”  Years ago, one might have responded with a smart remark about microbes and mosquitoes inheriting the earth. Now, as we enter a new age of genomics, DNA Repair.jpgtranscriptomics, metabolomics and all sorts of other ‘omics, the way we think about genetics, heritability and evolution is undergoing its own rapid evolution, the notion that human populations can undergo evolution as a consequence of our own folly no longer seems so far-fetched. Still it’s a complicated question. And so we might begin with a few more manageable questions: 1) are humans still evolving 2) if we are, how rapidly can we evolve and 3) what kind of threat would be required to elicit rapid evolution in humans? To some degree, human culture, technology and behavior, have enabled us to sidestep natural selection, likely altering our evolutionary trajectory. Even so, according to evolutionary biologist Stephen Stearns and colleagues, humans have not yet become a static, unchanging species. “[T]raits in many human populations,” they write “are subject to natural selection, and have the genetic potential to respond to it…” in other words the pieces for evolution to occur in humans are in place (see Measuring selection in contemporary human populations by Stephen Stearns et al.,) At the very least, certain human traits (age at first birth, height, and menopause for example) remain susceptible to selection, which means that despite our advances we have not yet become a “post-evolutionary” species. This is a good thing because for a species to no longer evolve, its differential survival and reproductive success must no longer be under genetic control – an unsettling prospect given how well these interactions have served life for the past 3.5 billion years or so. Yet before we celebrate, we ought to consider the second question, how rapidly could we evolve? Read more.