In fact, we are already dependent on machines. As much as we build them to meet human needs, we have structured our own lives and behavior to meet theirs. As machines become ever more complex and interconnected, we will be forced to try to accommodate them. Darwinian evolution, in one of those paradoxes with which life abounds, may be a victim of its own success, unable to keep up with non-Darwinian processes that it has spawned.
Our technological prowess threatens to swamp the old ways that evolution works. Consider two different views of the future taken from an essay in by evolutionary philosopher Nick Bostrom of the University of Oxford.
Organisms get smaller as well as larger. But evolution has indeed shown at least one vector: toward increasing complexity. Perhaps that is the fate of future human evolution: greater complexity through some combination of anatomy, physiology or behavior. If we continue to adapt and undertake some deft planetary engineering , there is no genetic or evolutionary reason that we could not still be around to watch the sun die.
Unlike aging, extinction does not appear to be genetically programmed into any species. The darker side is all too familiar. Bostrom who must be a very unsettled man offered a vision of how uploading our brains into computers could spell our doom. Advanced artificial intelligence could encapsulate the various components of human cognition and reassemble those components into something that is no longer human—and that would render us obsolete.
Meanwhile there is gradual progress in neuroscience and artificial intelligence, and eventually it becomes possible to isolate individual cognitive modules and connect them up to modules from other uploaded minds Modules that conform to a common standard would be better able to communicate and cooperate with other modules and would therefore be economically more productive, creating a pressure for standardization There might be no niche for mental architectures of a human kind.
As if technological obsolescence were not disturbing enough, Bostrom concluded with an even more dreary possibility: if machine efficiency became the new measure of evolutionary fitness, much of what we regard as quintessentially human would be weeded out of our lineage.
Perhaps what will maximize fitness in the future will be nothing but nonstop high-intensity drudgery, work of a drab and repetitive nature, aimed at improving the eighth decimal of some economic output measure. In short, humanity's future could take one of several routes, assuming we do not go extinct:.
Symbiosis with machines. Integration of machines and human brains produces a collective intelligence that may or may not retain the qualities we now recognize as human. The Future of Human Evolution. Edited by Charles Tandy. Ria University Press, Benjamin F. Pardis C. Sabeti et al. Barreiro, G. Laval, H. Quach, E. Patin and L. Quintana-Murci in Nature Genetics , Vol. Gregory Cochran and Henry Harpending. Basic Books, Already a subscriber? Sign in. Thanks for reading Scientific American.
Create your free account or Sign in to continue. See Subscription Options. Discover World-Changing Science. The Far and Recent Past Tracking human evolution used to be the province solely of paleontologists, those of us who study fossil bones from the ancient past. Recent reports show that there's a whole generation of teenagers with overdeveloped thumbs due to playing too many video games.
Muscles are able to adapt through excessive physical use, but this is not genetic. An individual may develop such a characteristic but will not pass this on to any offspring. Many geneticists claim that something new is happening in human evolution - something along the lines of a 'grand averaging' of our species. Basically, we are becoming more alike. Human evolution relies on the differences in our genes and in our ability to pass on these genetic differences ie our breeding capabilities.
Over time, the population should change as these differences become more apparent. If the genetic changes are great enough, a new species will arise. However, the three components required for evolution to occur - variation, natural selection and geographic isolation - have more or less disappeared from the equation.
Humans can be considered a single genetic 'continent' - meaning that the world's population is mixing and is no longer just breeding within cultural or ethnic groups. The idea is that as their bone density gradually declined in the low-gravity environment, the colonists' bigger bones might retain enough strength to ward off dangerous fractures. Evolutionary pressure for beefier skeletons might be especially strong for female Mars colonists, Solomon said, given the risk of pelvic fractures during childbirth.
Beefier skeletons or not, Solomon said, female colonists might come to opt for cesarean section over natural childbirth. And since the size of the human head is constrained in part by the dimensions of the birth canal, the heads of Mars colonists might become larger than what is seen in humans on Earth.
So Mars colonists might have beefy bones and big heads. Then there's the question of their eyes. Mars is much farther from the sun than is the Earth, and the extra distance — and the lower levels of sunlight on the Martian surface — could cause changes in the colonists' eyes. If there has to be some adaptation to these new ambient conditions, then either our optical system and brain will have to develop new ways of collecting more light on the retina, or we will develop new retinas or bigger eyes.
The need to protect those bigger eyes might be another reason the colonists' skulls might become more robust, Cabrol said, adding that it wasn't clear whether the changes she envisions would be evidence of a new species or simply a version of Homo sapiens adapted for life in a different environment. Of course, evolutionary changes in humans on Mars would occur only if humans were able to reproduce and successfully raise their children in the low-gravity Martian environment.
Cabrol said the colonists might need some sort of "gravity chamber" in which to reproduce and in which their offspring could spend their early developmental years in conditions closer to those on Earth. The Martian atmosphere is thinner than Earth's, and the red planet has essentially no protective magnetic field. Thus people living on Mars would be exposed to high levels of cancer-causing radiation even if they spent most of their lives indoors.
Pigmentation helps block the effects of radiation. The deeper the color, the better the protection. Thus Solomon figures Mars people might evolve to have darker skin than anyone on Earth. Since stable separation of parts of the species is the key factor for the formation of new species, we can say that a new split of our species is impossible under current circumstances.
We are globally connected as never before and this trend is accelerating. The only realistic scenario for the evolution of two species out of ours would probably be if we expanded beyond our home planet and then lost contact with the settlers. If both populations survived long enough — much more than , years — we might see divergence and maybe two species of humans.
We might get the evolution of new human species if we colonise other planets where people have to adapt to an alien environment. Mars, for example, is further away from the sun so residents there may evolve bigger eyes to see better in the dimmer light.
And without life, Mars is essentially a sterile environment and this may make Martian colonists more susceptible to disease so that mixing with people on Earth is discouraged.
This could rule out sex and increase the chance the colonists would develop into a new species.
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