Attention biology nerds

Attention biology nerds Jan 11, 2018 21:17:16 GMT

Quote

Post by Terrapin Station on Jan 11, 2018 21:17:16 GMT

Jan 11, 2018 21:09:18 GMT Lugh said:

Jan 11, 2018 21:06:21 GMT Terrapin Station said:

It doesn't work that way (when we're talking about biology re genetics). It's not like there's an obstacle, and then the organism makes an effort or decision or anything like that to adapt to the obstacle.

The obstacle might simply kill off the species. That's one option.

However, there might be differences among individuals that makes it more likely that some will survive the obstacle to reproduce. Those differences will be more likely to be passed on. It's nothing that anything made an effort to change.

And there can be mutations that make the species more successful in dealing with the obstacle. Those happen effectively "randomly." Again, there is no effort or decision or anything like that involved.

The mutations might have multiple benefits. But it's not like one was a planned benefit and the other was accidental. There is no planning in this.

Wouldn't there be evidence that organisms have the same new mutations in all environments then?

I am not saying you are wrong, just enquiring.

? I don't really get what you're asking. Genetics are more complex than it simply being a case of "parent has mutation x, so offspring, all offspring from that point on, will have mutation x." The mutation might get passed on, it might not. It might be passed on to some offspring and not others. Offspring aren't an exact copy of the parents' genetics, especially in species that reproduce sexually. In that case, offspring have a combo of the parents' genetic material, where the combos happen in complex ways. On top of that, there will be "mistakes" as well, or new mutations.

I forgot in the earlier post to address this by the way:

"there is a cause and effect relationship between the presence of challenges and adaptions"

There isn't a cause and effect relationship (not between the environmental challenge and the mutation). That's not how it works. And again, the species might simply die out. That happens all the time. There have been tons of extinctions of species. Per some estimates, 24 species currently go extinct per day. That's believed to be a much higher rate than historical rates, but even if it were 24 per year, or 24 per ten years or whatever, that's still a lot.

So species do not evolve just because they're presented with challenges that will affect their ability to produce offspring. The species that experience mutations that enable them to survive in the face of challenges are akin to species that hit the lottery. And like the lottery, it's random (that is, epistemically random; it's not ontologically random)