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> After all, selection works on an individual organism, and it's binary: either the organism survives, reproduces and passes on its genes, or not Not quite. Se

by Yen 11y ago

> After all, selection works on an individual organism, and it's binary: either the organism survives, reproduces and passes on its genes, or not Not quite. Selection isn't a 'did reproduce' / 'did not reproduce' binary - there's lots of in-between. 1. At the macro level, any given trait doesn't exist in a single organism, it exists in multiple organisms. Even assuming that an organism reproduces only once, or not at all, among a large population, the individual binary gets washed into a larger, fuzzy, aggregate. 2. A "binary" seems to assume that an organism can reproduce only once - many organisms reproduce multiple times. 3. A "binary" seems to assume that once reproduction happens, the vote is cast and the trait has (at least in aggregate), "won". Merely reproducing isn't good enough, though - most complex organisms have to continue to rear their young after birth.

zkhalique 11y ago
Yes, obviously the binary decisions are being aggregated, but at the end of the day, everything is filtered through these binary decisions. It's not like "I survived and reproduced and it was all because of X". It's just a binary outcome every time an animal reproduces. It's a vote for a certain combination of traits out of myriads, and now you have to show mathematically that this sort of selection can lead to evolution. And also keep in mind, the "beneficial" mutation step happens in only one animal, that had the mutation when the genes combined to form its genetic expression. And you need several of these steps. It's not like all of a sudden a bunch of proto-birds started to develop wings. Just one animal developed a proto-wing trait, and then reproduced along with 99.99% of others who didn't. But then, the proto-wing happened to be so beneficial despite not conferring an ability to fly, that the proto birds with the proto wings simply died less than the other 99.99%, and started growing in prevalence. And all this still assumes that, at every step from non-wings to wings, the improvements were beneficial for genetic fitness. Now, what if they weren't? How can evolution wait until a string of mutations detrimental to fitness takes place? Wouldn't that make the population with the proto-wings actually shrink -- when it was already 1 animal or so, it might actually be eliminated if we assume proto-wings were genetically disadvantageous before becoming wings? Again, there is no math in these explanations. Just descriptions and handwaving. Where is the actual math backing these claims and the explanation of the mathematical results! How does it actually work out? It clearly doesn't seem like it should!

by Yen 11y ago

zkhalique 11y ago

Yes, obviously the binary decisions are being aggregated, but at the end of the day, everything is filtered through these binary decisions. It's not like "I survived and reproduced and it was all because of X". It's just a binary outcome every time an animal reproduces. It's a vote for a certain combination of traits out of myriads, and now you have to show mathematically that this sort of selection can lead to evolution. And also keep in mind, the "beneficial" mutation step happens in only one animal, that had the mutation when the genes combined to form its genetic expression. And you need several of these steps. It's not like all of a sudden a bunch of proto-birds started to develop wings. Just one animal developed a proto-wing trait, and then reproduced along with 99.99% of others who didn't. But then, the proto-wing happened to be so beneficial despite not conferring an ability to fly, that the proto birds with the proto wings simply died less than the other 99.99%, and started growing in prevalence. And all this still assumes that, at every step from non-wings to wings, the improvements were beneficial for genetic fitness. Now, what if they weren't? How can evolution wait until a string of mutations detrimental to fitness takes place? Wouldn't that make the population with the proto-wings actually shrink -- when it was already 1 animal or so, it might actually be eliminated if we assume proto-wings were genetically disadvantageous before becoming wings? Again, there is no math in these explanations. Just descriptions and handwaving. Where is the actual math backing these claims and the explanation of the mathematical results! How does it actually work out? It clearly doesn't seem like it should!