alt Hacker NewsThis is one of those times evolution doesn't make sense to me. It's clear how a giraffe's neck evolves, the ones that could reach higher leaves in trees had an advantage. In examples like this, how does this evolve when there is no gradual change? An animal had to exist that had an offspring that somehow both absorbed the chloroplasts of the food it ate in a way that it could use (not just simple digestion), then have a place to store them, then have a mechanism to move the chloroplasts to the storage space, then have the mechanisms in their body to use the energy the stored chloroplasts create. How does that happen gradually when each step is totally useless without the others?
(please note I am not challenging the scientific truth of evolution, I simply do not understand how something like this happens)
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They look kind of translucent to me, maybe the first of this kind of slug just had a digestive problem that didn't break down the chloroplasts, and the minimal energy through their bodies made those individuals more successful because they didn't need to eat as often as those who digested theirs. Yada yada other errors among the indegestible-chloroplast population showed further advantages when it's closer to the skin, they outcompeted their peers, etc.
> please note I am not challenging the scientific truth of evolution
Evolution isn’t a matter of faith, you’re welcome to challenge it and try to poke holes in it.
The article notes that the chloroplasts are like a larder that the slug can digest when needs be, so storage could have come well before photosynthesis was actually utilized.
Or maybe it was photosynthesis first. The chloroplasts just did their thing for a while, and slugs that digested them slower (and eventually ones that stored them) got more benefit than ones that didn't.