"Evolution's plan"?
Evolution can't have plans, but a lot of people talk as if it did
When talking about trans people, or body hacking more generally, people sometimes say that it is "against evolution's plan". The problem is that evolution can't have a plan.
First of all, a plan requires a mind capable of planning. Evolution is a process, not a creature, and doesn't have a mind. But fine, perhaps we're speaking metaphorically, as one might say that an electron "wants" to be in the lowest energy state despite the fact that it has no mind to form desires with. It's a slightly inaccurate way of putting it, but everyone knows what we mean.
But there's another problem too. Saying an electron "wants" to be in the lowest energy state is a helpful metaphor because that's a fixed tendency we can observe in electrons. But evolution is the opposite of fixed. It's reactive, driven entirely by external circumstances. Not only does it not know where it's going, we also can't know where it's going until it gets there.
So why do people talk about "evolution's plan"? I think in previous generations, they might have said "God's plan" instead. God as described in many religious texts definitely has a mind capable of forming and carrying out plans, so that would make a lot more sense. But religious arguments have fallen out of favour since most people agree you can't make people who don't share your faith live by its rules.
They replace the overtly religious "God" with the superficially scientific "evolution", but they don't change the fundamental way they're thinking about what's going on. Maybe their concept of "evolution" is less clear and more gentle than their concept of "God", but it's still something they imagine as having human-like thought processes.
And I get it, to an extent. It's very comforting to think that Someone, Somewhere, understands what's going on and is directing it. For everyone who finds it liberating not to be bound to a particular fate, there's someone else who finds it confusing and disorienting to be at the mercy of impersonal forces. And maybe most of us fall into both categories, depending on the situation.
We all have the right to whatever myths and metaphors help us make sense of the world, but it's important to be aware that they are myths and metaphors, not absolute truths. When people give their hankering for a plan the scientific gloss of "evolution", there's a risk that they'll lose sight of that.
That's when we see transphobes insisting that their soundbites about how bodies are "designed" are "science", while actual observations about how malleable bodies actually are is "ideology". They've confused their metaphors for the reality those metaphors were supposed to represent, and the cognitive dissonance comes out in increasingly nonsensical justifications.
One of my favourite ways of looking at the scientific method is that it's a tool to minimise the effects of human bias. Not eliminate, because as long as humans are carrying it out, there will be sources of bias, but reduce as far as possible. Scientific knowledge is always provisional: the best accuracy we've managed so far. Appealing to "science", or to scientific concepts like evolution, for the certainties we used to get from religion misses a lot of the point of how science works.
And again, I get it. Certainty is comforting. Uncertainty breeds doubt, insecurity, anxiety. Our squishy meat brains aren't really equipped to grapple with these things.
Because if evolution did have a plan, it wouldn't be to make us as smart as possible. It would just be to keep us alive and reproducing. And last I checked, we're managing pretty impressively at that. With the help of technology, we can survive things that would have killed us in the wild, and reproduce despite factors that would have rendered us sterile.
Evolutionary change happens on a much slower timescale than our current technological progress, so it's much easier now to look at the ways we've shaped ourselves than the ways evolution has shaped us.
We're still limited by our biology in some ways, and probably always will be, but with technology we can keep pushing at those limitations. You are, of course, free to argue that we should not, but you need to be clear that you're making a values-based argument. If the cost - in resources, in damage to the environment, in the potential for human exploitation - is too great, then make your case, and we can debate it on those terms. But trying to argue that it runs contrary to "evolution's plan" is incoherent and muddies the debate.