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The individual would still have other relatives who would pass on the genes, like sisters, brothers, other family members. If the individual's sacrifice helps t
by tbirdz 11y ago
The individual would still have other relatives who would pass on the genes, like sisters, brothers, other family members. If the individual's sacrifice helps the group survive, their genes would be passed on in those relatives. Also note that the gene would only be activated under a certain set of circumstances, so individuals could have the "self-sacrifice" gene and pass it to their children, even if they never encountered the set of circumstances that would induce suicidal ideation themselves.
I believe there is similar thinking for genetic passing of traits like homosexuality.
- haberman 11y agoThat explanation doesn't make sense to me. Your brothers/sisters etc. have similar genes, but they don't have your genes. The theory of evolution is that the most fit genes propagate. So if your brothers/sisters propagate but you don't, then your brothers/sisters genes (along with whatever mutations they might have) are being selected over yours, just as if you had some mutation that made you overall less fit.
- tbirdz 11y agoThe most fit genes propagate, not the most fit individuals. Your siblings have many of the same genes that you have. Say there is a gene A that will result in some individuals not reproducing, but will result in more members of their group reproducing. Now say there is 1 group where the members of the group have gene A, and another group where the members don't have gene A. Over time the group with gene A will reproduce more than the group without A, resulting in more copies of A in the general population. Even if some individuals in the group do not reproduce, their relatives in the group do reproduce. So say 1 person self-sacrifices and does not reproduce, and as a result of their sacrifice 10 others in the group survive and reproduce that would not have been able to if the first individual had not self sacrificed. The family all has gene A, so this results in a net gain of 9 individuals with gene A. So the amount of people with gene A increases, even though some individuals with gene A potentially do not survive and reproduce. If you want to learn more about this kind of thing, look into "Selfish Gene Theory".
- haberman 11y agoI guess this works if you separate the idea of "fit for a particular situation/environment" for "fit in general." Suppose we did not separate these things. In that case, for an entire group to have A, that implies that some ancestor of that entire group had A. But this contradicts the premise that the gene makes people less likely to reproduce. It works if you accept the idea that genes which are fit in some situations are less fit in others. In that case you could have a person who developed this mutation of feeling suicidal when they feel useless, but it doesn't "activate" because they aren't in a situation where they feel useless. But once a whole group has this gene, then your theory of propagation through siblings/cousins is more plausible.
- balfirevic 11y agoIt's called kin selection and I think it's generally accepted within scientific community to be a real phenomenon. https://en.wikipedia.org/wiki/Kin_selection https://en.wikipedia.org/wiki/Kin_selection
- haberman 11y agoThat addresses my question exactly, thanks!