• Apathy Tree@lemmy.dbzer0.com
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    8 months ago

    So like I know horseshoe crabs have been around nearly unchanged and all. And good for them!

    But are you (general you, not op specifically) really trying to tell me that not once in their entire historical span of time on earth… not one single time did anything evolve from a horseshoe crab?

    Clearly I’m not saying the whole species changed, but that is separate from an offshoot population evolving into something different. Which surely must have happened, no?

    • theneverfox@pawb.social
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      8 months ago

      Weirdly enough, evolution isn’t random - it follows rules. We’re still figuring out what those rules are, but it does in fact reach a certain point, then lock down the genes.

      Horseshoe crabs are chemically incredible, they’re extremely resilient and physically pretty good for their niche

      Maybe they are a genetic endpoint

      • Apathy Tree@lemmy.dbzer0.com
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        8 months ago

        Do you have any citations for that?

        I’m not saying you are wrong, because I’m open to new information, but that’s not ever been my understanding of how evolution works, and I’ve read a ton on the topic.

        Evolution continues even if a species doesn’t obviously change over time. Unless it’s an asexual reproducing species, gene recombination ensures some level of diversity, and more opportunity for novel traits. But even a clonally reproducing species have a chance for mutations, they are just significantly more likely to be detrimental than useful.

        • barsoap@lemm.ee
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          8 months ago

          You’re in for a treat. The basic situation is that physiologists are watching it in real-time, neo-Darwinists have a hard time accepting it because “it’s not necessary for evolution to work”, physiologists then wish they could batter the neo-Darwinists with their microscopes until they relent.

          Noble is going over more but as a programmer, the information theoretical argument is close to my heart: DNA transcription, if left completely to its own devices, has a quite high error rate. Correction mechanisms (which evolved completely randomly at some time) then take that error down to practically nothing, and after that randomness is again introduced. Which means that evolution (or, well, how many a genome evolves) is not a random process, but a process employing randomness, enabling it to strategically choose where to mutate. The genome of a bird, for example, if it senses that the current phenotype can’t get at nectar, is well-advised to mess around with beak shape genes instead of mitochondrial DNA, and this “different environmental stressors cause different genetic transmission” is indeed what physiologists are observing and I don’t just mean epigenetics. It’s not that the same result couldn’t be achieved by pure, blind, randomness, it’s that a genome able to employ strategic randomness is more fit, can adapt faster and more successfully. And as it’s a metasystem transition it gets locked in, there’s no backsies because any deviation from that kind of achievement is always less fit than one that retains the capacity, same as you don’t see DNA-using life suddenly ditching it, being content with only RNA.