Comments on Sanford and Carter respond to PS participants

[thoughtful (Valerie (non-scientist))]

@CrisprCAS9

For the sake of the moderators, and as requested, I’m replying to you here from the other thread.

Thanks for responding to me here.

@CrisprCAS9

I don’t think I’ve read @Rumraket as saying we know specifically what the DFE for neutral mutations is. Just that more mutations (of all sorts) are deleterious than beneficial. This is clearly true, but doesn’t imply anything about the detailed DFE for neutrality.

Ok. I guess I’ll let him answer that.

Looks like he did.

@Rumraket

I am not making a claim about the relative proportions or magnitudes of the [neutral and deleterious] ones, merely that they outnumber beneficials. Just hypothetically, they might outnumber beneficials 80d+n:20b, or 90d+n:10n or even further, depending on how far into high levels of fitness the population already is.
But then the [neutral+deleterious] fraction might itself be split [70d:30n], or [50d:50n], or [30d:70n] or w/e.

I don’t know the distribution within the neutral fraction, but even if it really is somehow close to how Sanford imagines, I’ve already given very good arguments (supported by real empirical evidence) for why his conclusion of inevitable and indefinite fitness decline physically cannot occur.

I haven’t seen these arguments supported by empirical evidence, or missed them, so please link me.

@Rumraket

It makes scientists look unscientific that they really care about being precise and correct in their characterizations of real data? Then perhaps what you find mildly amusing is itself an argument that you’re not being all that reasonable.

No what I meant. I meant missing the forest for a tree.

@Rumraket

Compare those historical values to the modern rate at the bottom. From about a quarter to roughly half of all children died before they reached adulthood. That’s an enormous selective pressure.

So since only the most modern data show a difference, we only have relaxed selective pressure now in the era we live in?

@Rumraket

Yes, there is a vast literature on this, and among it are also publications that put these numbers into an evolutionary context. Population geneticists such as Michael Lynch have pointed these things out:

I’ll read it.