The Rate of Evolution vs The Rate of Environmental Change
So we’re heading towards, or in the middle of, a mass extinction event. Obviously, this is very bad. Today it was too hot in San Francisco. Apparently, it was very cold in New York. This will kill lots of plants that are beginning to bud, this will make it harder for animals, etc., etc. The point is, the climate is changing, and life can’t adapt fast enough to survive. What’s interesting about that sentence is the “fast enough” portion. In the history of the planet, life has, quite frequently, actually near constantly, adapted to survive. It has just been very slow, relatively. Now, some of this hasn’t been species actually adapting to survive in new conditions, rather they have died off and ceded their resources to species whose characteristics were better suited to the new environment, but nonetheless, enormous extinction events have been relatively infrequent.
Ok, that’s the introduction, the reason I’ve been thinking about this. To speed this up, I’m going to write down some axioms for this blog post:
There is a rate of environmental change that is somewhat “typical”. For example, temperature has changed (slowly) over time.
This “typical” rate of environmental change isn’t associated with mass extinctions
Evolution produces adaptations or new species in part as a response to this change.
Mass extinction events can be caused by the environment changing too quickly for species to successfully adapt.
These axioms are probably not totally right. Let’s ignore that for now and assume they’re true. Let’s assume that some mass extinction events are partially the result of the rate of evolution being too slow for the rate of environmental change. Is there a “typical” rate of evolution that has “evolved” as a result of the “typical” environmental rate of change of the planet? What would evolution look like on a planet with a much higher rate of “typical” environmental change?
How does evolution, as a process acting on species, get shaped by the nature of the environment that these species exist within?
There’s another question we can ask about this that perhaps has slightly more of a sense of urgency around it: how quickly can cultures evolve?
We often hear that cultural beliefs change when the older generation dies off. To what degree is this true? A problem like climate change, which requires urgent action, can’t wait for the older generation to die off. Have we created a world that is changing too quickly for us to keep up with? The internet certainly seems to have increased the potential rate of cultural evolution, but surely, there’s a limit. What is it? How would we discover it?
I’ve been thinking about this lately in part because of the nationwide Black Lives Matter and anti-police brutality protests. I’ve been struck by how different, how much less divisive, these protests are than the Ferguson protests of 2014. Even if we look at the NFL players kneeling less than a year ago, the public was genuinely divided about them! Now we have every fortune 500 company coming out and saying “Black Lives Matter”, which is the surest sign that an issue has passed from politically divisive → accepted as uncontroversial.
