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> Biologically, it's still reproductive failure. On the contrary, how many children one has is ultimately selected by evolution. For a given species in a given
by lutusp 12y ago
> Biologically, it's still reproductive failure.
On the contrary, how many children one has is ultimately selected by evolution. For a given species in a given environment, there is an optimal number of offspring. Too few or too many, and the trait is selected against.
This is the simplest calculus of natural selection. What this means is there is no "reproductive failure" in the sense you propose, there are only the blind choices natural selection makes. And the successful blind choice is not always "as many as possible", not in any real environment.
> A culture that chooses to not have children is a culture that has decided to stop existing.
So tell me the names of Einstein's children. Give up? They're special and general relativity, and the photoelectric effect. They look great in family group portraits.
My point? In modern times, ideas have a life of their own. Some people choose to have ideas instead of children. Some of those ideas have an influence that no child could possibly equal.
- sbierwagen 12y agoOn the contrary, how many children one has is ultimately selected by evolution. For a given species in a given environment, there is an optimal number of offspring. Too few or too many, and the trait is selected against. No adaptation ever selects for zero children. (Edit: replace gene with adaptation)
- dllthomas 12y agoThat is clearly false. Notwithstanding mutations that aren't going to stick around, you also have to contend with non-reproductive castes in social insects.
- JoeAltmaier 12y ago...and in social people!
- dllthomas 12y agoWe don't have "non-reproductive castes" in quite the same sense...
- sbierwagen 12y agoBoth of your counterexamples are bogus. 1.) Workers in eusocial insects are more related to their sisters (75% similar) than they are to their own offspring (50% similar). This results in selection pressure that favors cooperation, rather than producing your own children: http://en.wikipedia.org/wiki/Evolution_of_eusociality http://en.wikipedia.org/wiki/Evolution_of_eusociality 2.) Deleterious de novo mutations are, obviously, deleterious. Duh. I didn't say that all genes are beneficial, I said that no gene selects for reduced fitness.
- dllthomas 12y agoYour first point is simply a statement of reason why a gene for zero children (under some circumstances) might be selected. Obviously there are such reasons, since there are such creatures! In no way does that make it a bogus example - in fact, it's quite relevant to the parent conversation, with an acknowledgement that the selection pressures would be weaker. The second point, I'll grant - though with the qualification that your language is tremendously imprecise. Genes don't select at all. Evolutionary pressures (plus happenstance) select between genes. That messiness is partly why it got a "notwithstanding..." aside, rather than a full example.
- dllthomas 12y agoWhat is clearly true is a more restricted version - no gene will be selected for if it causes zero reproduction (of any sort) across all carriers. But that's also basically irrelevant to the discussion.
- lutusp 12y ago> What is clearly true is a more restricted version - no gene will be selected for if it causes zero reproduction Like the genes that cause someone to become a doctor and minister to his/her genetic cohort? I think your argument doesn't go deep enough into how genetics works. We should all remember that reproduction isn't about individuals, it's about genes. The old question about the chicken and the egg actually has an answer -- a chicken is an egg's way to make another egg.
- dllthomas 12y agoI think there's a biological sense in which it's reasonable to call it a "reproductive failure", but that sense does not contain any normative content and is inapplicable in a policy context so I don't think it makes sense here.