Try talking about biological operations without invoking “function”. Claiming it’s “convenient” to do so doesn’t cut it: convenient for what?
Why do acorns become oak trees? They must be causally ordered toward that end. That’s telos.
Even efficient causality presupposes telos. Why does striking a match against a matchbox consistently produce fire? Because the match has a causal ordering toward that end. Otherwise, you could not explain why fire consistently results as opposed to random things like a flock of seagulls or a BMW 7 Series…or nothing at all.
Telos is not necessarily a matter of some external purpose or Paley-style watchmaker. That’s mechanistic metaphysics appealing to a watchmaker to explain a purpose things would - under that metaphysics - inherently lack. It is a matter of causal order and directedness.
If you had a strong vendetta against mistaking map for territory, you could very well talk in terms of past survival and statistics. It's just not necessary for regular biological talk. It becomes relevant only when you start going to the boundaries.
> Why does striking a match against a matchbox consistently produce fire?
Because you wouldn't call these objects a "match" and a "matchbox" otherwise.
There's no force and there's no goal. These things happen because every moment is a direct consequence of the previous one.