Monday, May 23, 2011

The Two Main Ways In Which Evolution Is Not Our Friend

With millions of years of evolution behind our species, and a billion behind life in general, we might expect - in a Panglossian frame of mind - to function very well, and to be free from unnecessary misery. Wouldn't the ruthless process of selection have removed causes for fitness-draining suffering and poor well-being in general?

There are two main reasons why we should expect a great deal of unnecessary suffering to be the product of evolution.

1. Adaptation Executors

A maxim of evolutionary biology is that organisms (like us) are adaptation executors, not fitness maximizers. Evolutionary processes create organisms that execute biologically-mediated strategies - it does not create rational beings that maximize fitness in all instances.

In many cases, the detection mechanism is "too sensitive" for our own good - our pain response and our startle response, for example, both generate lots of "false positives" in terms of fitness threats we may respond productively to. This is because in the environment of evolutionary adaptedness, the cost of tons of false positives was outweighed by the benefit of being "right" that one time that counts.

Our social ostracism detection system has also been posited to be hypersensitive, for the above evolutionary reasons. Social belonging has such a high survival value that any potential threat must be addressed immediately. This is true even if it means 100 "false positives" - instances of social ostracism with no actual fitness threat - must be suffered by the individual organism.

What's a good idea for evolution is not necessarily a good idea for you. Evolution works fine - it just doesn't give a fuck about the well-being of individual organisms.

2. Failures

In other cases, complex systems interact in such a way that the detection system is "broken." This may be because the EEA doesn't match current conditions, as may be the case with asthma, allergies, diabetes, and obesity. In other cases, it may be because organisms aren't created perfectly every time, and are not perfectly matched even to EEA conditions. Evolution can only act on the mutations it's given. The pain of a migraine, for instance, is not an indication of a necessary response the way the pain from a burn is. Problems may not reflect any adaptation at all - it might be a defect in the system, or in the organism.

Written in response to this comment by The Plague Doctor.


  1. I think your point #2 is really two points. One is simple failures, both on a species-wide level and on an individual level. An example of the former is that our alimentary canal intersects our respiratory system, and thus the fact that we can choke to death, is simply a case of "incompetent design". And then we're all messed up individually in various ways.

    The other point that you have under "2. Failures" is that we did most of our evolution in groups of <150 or so individuals who were highly related, were physically active, didn't accumulate wealth, had much less hierarchical a social structure, were non-monogamous, lacked the ability to provide for themselves individually, etc.. Lots of characteristics that were adaptive in that environment are maladaptive in the modern environment.

    Evolution can very quickly pick out especially advantageous alleles that preexist, but it takes crazy-long to come up with something new. We had around a thousand generations since we've been a sedentary, agricultural, urban, hierarchical, wealth-accumulating species, which isn't very long to change around what worked pretty well for pre-historic Homo sapiens (and, hell, for Homininae (Homo + Pan) generally).

  2. Yes - the "Civilization and Its Discontents" issue (that we adapted to different conditions) kind of bridges the two categories, in my view. It's a little bit that we're adaptation executors, not rational fitness maximizers, and it's a little that the adaptations are now horrendously mismatched to the environment - big fail.

  3. Sure, but I think that even organisms that exist in the environments in which they evolved for far more than a thousand generations (adjusted for mutation rate and population size and selective pressures and other stuff) have failures, both on a species-wide level and on an individual level. Chimpanzees have the poor design feature of intersecting tracheas and esophaguses even though they live in their ancestral environment. Individual chimpanzees also get screwed up just like individual humans get screwed up.

    This seems like a niggling point to argue over, but I guess I don't see how the two categories--pure error and mismatch-to-the-environment--have much to do with each other other than they make things suckier. Of course, for a <strike>pessimistic</strike> realistic blog like yours, suckiness is a unifying theme, but you're also interested in analyzing suckiness and seeing what we might overcome or avoid and what on the other hand we're stuck with.

    Completely unrelated, a post I'd be interested in seeing commenters' answers to would be this:

    "At a convention, or a bar, or a sex party, or a triathlon mixer, you meet Sister Y. Before the event, you acquire without effort or volition 10g of pentobaribital[1] in solution in a vial in your pocket. Do you give her the vial unprompted? If she asks you for it, do you give it to her? If you don't give it to her, what are you likely to do with it after the event? Explain.

    [1] The LD50 for rabbits is 40 mg/kg; for guinea pigs 60 mg/kg. So for a 60 kg mammal, it's 2.4g on the rabbit scale or 3.5g on the guinea pig scale.

  4. Jason, I suspect your hypothetical would get us into trolley-land. Very few of my friends would be willing to hand me the escape kit, but I doubt anyone would make a move to take it away from me, even if this could be accomplished surreptitiously. And I doubt this has anything to do with their feelings about my right to commit suicide, or their affection for me.

    But somebody eventually anonymously sent Chantal Sébire a proper dose of barbiturates - actually, in this circumstance and for Trolley reasons, an anonymous benefactor is probably much more likely.


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