'Homo sapiens' is a very rough category. If you would call a 250,000 year-old animal a homo sapiens, you'd probably call its grandparents one too. Time-frames used this way are only really applicable to talking about some static history, not active evolutionary processes.
Humans will still be Homo Sapiens in 1 million years as long as we still call them that. In other words, "how old" homo sapiens is is a rather arbitrary matter of convention, so it doesn't make a good argument.
> If you would call a 250,000 year-old animal a homo sapiens, you'd probably call its grandparents one too.
Sure, and conditional on that I'd probably call their grandparents H. sapiens too, and conditional on that, probably also their grandparents. But it doesn't take that many generations before all these "probably"s multiply out to a "probably not".
I don't think the distinction between homo sapiens and not-homo sapiens is so fuzzy that we can't distinguish between evolution working on 250,000 and 1,000,000 year timescales.
My point is that we distinguish species based upon their features, not timescale. So you cannot use this timescale-based differentiation to make a good argument to counter a feature-based differentiation.
How many generations would it take for some evolved feature to become part of homo sapiens has nothing to do with how many features are needed to not be homo sapiens anymore. Other than the fact that they both take time and are statements about evolution, there is no relation between the two.
> you cannot use this timescale-based differentiation to make a good argument to counter a feature-based differentiation.
I don't know what you mean by this. I don't know what feature-based differentiation I'm supposedly countering, and I don't know what it would mean to counter it.
What argument do you think I'm trying to make, exactly? Because all I'm saying is, "evolution makes significant changes on timescales significantly less than millions of years".
This thread isn't actually particularly interesting to me, so I may tap out now.
Humans will still be Homo Sapiens in 1 million years as long as we still call them that. In other words, "how old" homo sapiens is is a rather arbitrary matter of convention, so it doesn't make a good argument.