There must be a reason, though. If it were that easy to increase your brainpower that way, and there were no other drawbacks, this modification would already have been selected for.
If you take them, perhaps you will discover later why this potential evolutionary change was not beneficial, and not selected.
Maybe the ability to synthesize a particular chemical could not (or merely has not yet in humans) be reached by a single change, or a path of individually selected-for single changes. In other words, your argument only works if the reachability of the improvement is high enough, and our species has existed for enough time in an environment where it would be rewarded.
You’re right—my argument is intended for easily reachable improvements.
Your brain is full of neurons that are sending chemical messages to one another. For this to work, the brain has to be able to receive all the messages sent, and to send all the messages received. Your extra chemicals have to change this process somehow, and they can only do this by interfering with the signalling process. But your body already knows how to make these signals.
You’re not creating hard-to-reach improvements by adding chemicals. You can only alter the balance of the chemical network that already exists, and evolution has already balanced that network pretty well.
If you could do something more radical, like adding a different kind of signalling, or fundamentally speeding the thing up, then I’d be interested. But chemicals can do neither of those things.
Thanks. Good thinking about the possible mechanisms for a drug.
I only know of a few general mechanisms for drugs:
1) activate a receptor directly (as you say, this seems like something that evolution could possibly tweak). However, if there are other receptors elsewhere, then it’s possible that the chemical messenger reached by evolution will hit them all, whereas a synthetic compound could be more selective (e.g. SkQ1 is more targeted than anything we naturally produce and seems helpful).
2) block a receptor by partially occupying its jigsaw gaps (metaphorically)
3) act as a specific toxin, or react with another compound, consuming or destroying the target (e.g. chemotherapy—it seems like they’re going to be able to biopsy, sequence the particular cancer gene signature, and create a toxin just for that)
4) change something about the coarse chemical environment (acidity, osmality, etc.) to slow/increase a particular reaction
5) act as a virus, modifying DNA of all or specific cells (someday, maybe)
That’s all I can think of right now. I’m sure there are tons more. “receptor” is a pretty abstract concept.
Maybe the ability to synthesize a particular chemical could not (or merely has not yet in humans) be reached by a single change, or a path of individually selected-for single changes. In other words, your argument only works if the reachability of the improvement is high enough, and our species has existed for enough time in an environment where it would be rewarded.
I think you’re saying what I mean, but I’m not quite sure, so here’s how I came at it:
Evolution relies on mutation, and mutation is random. If a certain feature is currently observed, that doesn’t mean the mutation has already occurred and been selected against; it might just not have occurred, or not widely enough to catch on. For example—just because skinks lay eggs doesn’t mean live birth isn’t a good mutation for some of them.
In general, I don’t know that it’s ever accurate to talk about evolution in the past tense when referring to a living species.
You’re right—my argument is intended for easily reachable improvements.
Your brain is full of neurons that are sending chemical messages to one another. For this to work, the brain has to be able to receive all the messages sent, and to send all the messages received. Your extra chemicals have to change this process somehow, and they can only do this by interfering with the signalling process. But your body already knows how to make these signals.
You’re not creating hard-to-reach improvements by adding chemicals. You can only alter the balance of the chemical network that already exists, and evolution has already balanced that network pretty well.
If you could do something more radical, like adding a different kind of signalling, or fundamentally speeding the thing up, then I’d be interested. But chemicals can do neither of those things.
I think you’re assuming that all brains are in pretty good shape, but there are people who benefit tremendously from psych drugs.
It doesn’t seem implausible that there are people who’d benefit from less drastic tweakage.
Thanks. Good thinking about the possible mechanisms for a drug.
I only know of a few general mechanisms for drugs:
1) activate a receptor directly (as you say, this seems like something that evolution could possibly tweak). However, if there are other receptors elsewhere, then it’s possible that the chemical messenger reached by evolution will hit them all, whereas a synthetic compound could be more selective (e.g. SkQ1 is more targeted than anything we naturally produce and seems helpful).
2) block a receptor by partially occupying its jigsaw gaps (metaphorically)
3) act as a specific toxin, or react with another compound, consuming or destroying the target (e.g. chemotherapy—it seems like they’re going to be able to biopsy, sequence the particular cancer gene signature, and create a toxin just for that)
4) change something about the coarse chemical environment (acidity, osmality, etc.) to slow/increase a particular reaction
5) act as a virus, modifying DNA of all or specific cells (someday, maybe)
That’s all I can think of right now. I’m sure there are tons more. “receptor” is a pretty abstract concept.