January 6, 2008
Are We Post-Human Yet? Human Evolution Reportedly Accelerating.
It seems like yesterday when humans were living in caves, wearing animal skins, hunting with tree branches and rocks shaped like wedges, rubbing sticks together to make fire, and burning our fingers and food on said fires. To an anthropologist, “yesterday” means some tens-to-hundreds-of-thousands of years. But according to an article published by the Proceedings of the National Academy of Sciences (PNAS), human evolution has accelerated in the past 40,000 years. Here’s the link to download the PDF of the report.
Genomic surveys in humans identify a large amount of recent positive selection. Using the 3.9-million HapMap SNP dataset, we found that selection has accelerated greatly during the last 40,000 years. We tested the null hypothesis that the observed age distribution of recent positively selected linkage blocks is consistent with a constant rate of adaptive substitution during human evolution. We show that a constant rate high enough to explain the number of recently selected variants would predict (i) site heterozygosity at least 10-fold lower than is observed in humans, (ii) a strong relationship of heterozygosity and local recombination rate, which is not observed in humans, (iii) an implausibly high number of adaptive substitutions between humans and chimpanzees, and (iv) nearly 100 times the observed number of high-frequency linkage disequilibrium blocks. Larger populations generate more new selected mutations, and we show the consistency of the observed data with the historical pattern of human population growth. We consider human demographic growth to be linked with past changes in human cultures and ecologies. Both processes have contributed to the extraordinarily rapid recent genetic evolution of our species.
Evolution… or Revolution? While many see Darwin’s theories on evolution as being written in stone… and many religious zealots wanting to erase those theories permanently… there have been calls to update those theories, and not just from the “intelligent design” herds. An essay from the New York Times shows that some are making such calls for changes in the theory of evolution, saying that mutation is the main driving force instead of selection.
I remember seeing a story online about this mutation-selection: Every so often, several mutations develop in a population. Those mutations that survive best are allowed to continue. If you’ve read Rudy Rucker’s Software, you might remember in chapter twelve where Cobb and Sta-Hi went past a pair of museum displays, one showing natural selection, the other mutation, and Cobb explains how he came up with the idea of evolution for robots:
Selection and mutation. That was my big idea, Sta-Hi. To make the robots evolve. They were designed to build copies of themselves, but they had to fight over parts. Natural selection. And I found a way of jiggering their programs with cosmic rays. Mutation.
Where will post-humanity go from here? SFAM posted this short piece about a podcast debate on post-humanity. It’s mostly about bio-engineering, but should give you a good place to start.
According to this MSNBC article from 2005, human evolution is at a crossroad. Either bio-engineering will cause new forms of humans to emerge, or cybernetics will fuse us with machines. It’s also possible for both scenarios to occur simultaneously. But there is a group who may have the final word on how post-humans develop, if they allow them to develop: The health insurance companies.
ZDNet’s Mitch Ratcliffe posted a recent blog about his degenerating spinal discs and his need to replace them. He wants replacement discs, but his health insurance provider won’t pay for them, preferring Mitch to get the disc fusion done instead even though fusion causes more problems than the replacement and ultimately requires more surgeries. Unfortunately, logic never has a place where profits rule, and anything that threatens the bottom line (like lawsuits or healthy customers) are to be vilified:
The fact that disc replacement promises improved mobility in the joint isn’t a “benefit” insurers recognize. The operation was only FDA approved for a single disc until a few weeks ago, and I am in the midst of gaining approval for a “multi-level disc replacement” from my insurance provider. Unfortunately, my doctor tells me another of his patients, who works for and is insured by the same insurer I have, was just turned down for the single-disc surgery.
The other barrier to access is the Food and Drug Administration, which is consistently under-funded for product reviews. In medical technology, “beta” isn’t good enough, so we need a well-funded review process that doesn’t rely entirely on company research or company-defined FDA protocols. We also need to recognize that these are risky procedures that can lead to death, paralysis and lifelong pain if things go wrong — we can’t go lightly into cyborg markets like we play with gadgets.
Right now, we may become semi-cyborgs until genetic therapies become mainstream, or the insurance companies are willing to pay for them. It’s sad to think that the health insurance corporations would ultimately decide post-humanity’s fate, but evolution will still continue (deal with it Pat Robertson!), and we still have time to make a choice…
Mutant or machine?