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December 9

Evolutionary adaptation time and survival

Seemingly some complex adaptations, like evolving capsaicin in pepper to deter seed-destroying rodents, require quite a long time (possibly longer than some simple adaptations). If I understand correctly, the successful evolution of such traits require a more or less stable population over time. But in such cases detrimental factors that drive evolutionary adaptation seem to constantly diminish the overall population, thus reducing the probabilistic chances to evolve a beneficial trait - e.g. rodents eating early pre-capsaicin peppers were regularly damaging seeds, thus diminishing evolutionary chances for next-generation peppers - especially considering high reproduction rate of rodents that overwhelms pepper seeds. As the result, there should have been peppers with very few intact seeds which looks unsufficient to evolve a beneficial deterring trait over time.

On the other hand, if I understand correctly, the evolutionary pressure - that is detrimental factors - should be strong and persistent enough to produce such a beneficial trait, otherwise it may not evolve at all. How do organisms overcome this? Brandmeister^talk 09:00, 9 December 2023 (UTC)[reply]

Many detrimental factors are not so strong that they would lead to extinction; they are compatible with a stable population, allowing beneficial adaptations sufficient time to evolve. Other possible adaptations of herbaceous plants to seed-destroying rodents are to grow taller, so that the berries are not in easy reach of ground dwellers, as well as to grow more berries. Such simple adaptations develop in a shorter time, buying more time for more complex adaptations. --Lambiam 11:22, 9 December 2023 (UTC)[reply]

It appears there should be a fine balance in the strength of evolutionary pressure to produce a required trait in that regard - not so strong and not so weak, which, given the multitude of successful adaptations, honestly leads me to the fine-tuning argument. Brandmeister^talk 14:50, 9 December 2023 (UTC)[reply]

Found some papers that suggest this is indeed a challenge in evolutionary biology: [1], [2]. Brandmeister^talk 15:05, 9 December 2023 (UTC)[reply]

My understanding is that an evolutionary pressure killing one in a thousand is quite strong enough to lead to evolution in response. This is why if some gene hangs around that has some detremental effect it is always worth having a good look for what its other effects might be. Evolution normally proceeds on a number of genes at once so single mutations only have a minor effect unless they really do help or harm. NadVolum (talk) 16:59, 9 December 2023 (UTC)[reply]

Correct, most known natural selection pressures are so subtle that they are barely detectable statistically. A 1% selection pressure is considered crazy high. Abductive (reasoning) 20:17, 9 December 2023 (UTC)[reply]

Coumaric

Why are the coumaric acids called "coumaric"? How are they related to coumarin? --Lambiam 11:53, 9 December 2023 (UTC)[reply]

In the 1800s when coumarin was first isolated, one of the standard steps to work out what it was would be to hydrolyse it with e.g. NaOH. In that case, the lactone ring would open, giving the hydroxy cinnamate (although not initially the trans isomer). Naming would then follow, even if the complete structure was not then known. Mike Turnbull (talk) 12:12, 9 December 2023 (UTC)[reply]