Will Climate Change Make Us Smarter?
WorldChanging Essays
It did before, at least according to a growing number of scientists specializing in the evolution of the human brain.
When the hominid line split off from other apes about six million years ago, bipedalism and other physiological changes happened pretty quickly -- from the neck down. But it wasn't until about two-and-a-half million years ago that hominid brains started to really grow, from Homo habilis' ~500-600cc brains (chimps are a bit less than 400cc) to Homo sapiens' ~1400cc brains. The trigger for this cerebral explosion appears to be a period in which the global climate started going through a series of abrupt changes. Ice ages and warming periods flip-flopped, making it difficult for species relying upon particular environmental niches or conditions to survive. The species that did best were the ones able to evolve ways of dealing with rapid environmental changes; in the case of hominids, they got smarter.
We now face another round of climate disruptions, and this time it's happening far faster than the natural processes of past eras. Other environmental hazards abound, as well, threatening to make a bad situation worse. Will all of this lead, once again, to a new phase in human intelligence?
The BBC reports of recent findings confirming that the region in Africa home to important steps in the evolution of humans went through dramatic shifts in climate from 3 million years ago to 1 million years ago. Massive lakes formed and dried up at least three times in the period, indicating large shifts in moisture and temperature happening in a geologically short period (although far, far more gradually than the climate disruption underway today).
Dr. William Calvin, neurophysiologist at the University of Washington, has long argued that there's a connection between the evolution of intelligence and climate shifts. Calvin's 2002 book, A Brain For All Seasons, spelled out his argument in great -- and, to many, quite convincing -- detail. The book is still in print, but Calvin has also made the contents available as HTML here. Be forewarned; Calvin is apparently a great fan of Internet Explorer, and there are some weird rendering artifacts in Firefox and Safari on some pages.
Calvin's argument is interesting, in that the primary connection he draws between climate changes and brain evolution is that the environmental pressures led to a great need for cooperation between hominid individuals, and that increased cooperation required better communication abilities. Tools, fire, skinning animals for furs or to make skins to hold water -- all very useful, but what really let us survive was our ability to tell each other where to find food resources, how to make the tools and skins, plans for cooperatively bringing down larger prey or fending off attacks from predators, even ideas about what tomorrow might bring.
Would similar environmental pressures have the same result today?
Claims that humans are no longer subject to evolution aren't hard to find, and the more rational versions make the claim that natural selection pressures have largely been rendered moot through social cooperation and helpful technology. This may be so, and while something leading to the collapse of civilization may well lead to the resurgence of natural selection, it's reasonable to argue that society and technology allow us to expand "survival of the fittest" to a very large portion of the human population.
But if you think about the claims from Calvin and others that environmental pressure forced us to improve our communication skills and cooperative tools, it's not as clear that we're no longer subject to evolution.
It's certain that the potential disasters such as global warming-triggered climate disruption, oil depletion, and pandemics such as human-transmissible H5N1 are making us rely more and more on effective tools of knowledge acquisition and communication. Sites like the Avian Flu wiki, the Oil Drum, and yes, even WorldChanging and myriad others we talk about here on a daily basis are important parts of a structure for understanding and learning how to deal with disruptive changes. Sensors, computers and networks allow us better ways to recognize, analyze and tell others about changes to the world around us. Simulations and modeling can aid in seeing future opportunities and risks, and databases help to make sure that we don't forget them. Moreover, all of these tools are developing and advancing at a rate far exceeding biological evolution.
In short, we are improving our ability to communicate and cooperate, we're just not doing it biologically.
I do think that climate change and the various other big challenges we will face in the months and years to come will make us smarter, even if our cranial size is unaffected. We will be forced to develop better ways of understanding what's happening, looking for options, and cooperating on solutions. The ability to communicate clearly and completely will again be a species survival trait.
This is no reason to welcome global warming (or peak oil, or H5N1 pandemics...). It is, however, another reason for hope. Hominids, of which humans are simply the latest version, have demonstrated a remarkable ability to respond to environmental pressures, and each successive threat has left us smarter, more cooperative, and better able to handle what comes next. This time around, the dangers are potentially the worst the hominid line has ever faced -- but we also have the greatest resources the hominid line has ever possessed. This time, we may even be smart enough to head off disaster before it hits.
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