Dolphins and orcas have passed the evolutionary point of no return to live on land again
www.livescience.com
Scientists have discovered that once a mammal has become fully aquatic, it passes a threshold that makes a return to terrestrial landscapes almost impossible.
  • @Nath@aussie.zone
    45•1 year ago

    I don’t understand. Are dolphins campaigning for land rights or something?

    Maybe that’s the problem, they can’t hold signs to protest. Perhaps if we figured out a way to help them hold signs they’d be able to live on land again.

    Before we get to that point, has anyone asked a dolphin if they want to live on land?

    • @swnt@feddit.de
      7•1 year ago

      I don’t understand. Are dolphins campaigning for land rights or something?

      This made me laugh harder than I’m willing to admit

  • @blakerboy777
    10•1 year ago

    All life started in the sea. Transitioning back to semi-aquatic or fully aquatic has happened many times. Is it possible to transition back? According to these researches, it seems like a one way gate. The types of changes that land animals make to become fully aquatic again seem to lock a lineage into the water forever. Increased body mass and carnivorous diet are helpful going back to water but make it really hard to go back to land and redevelop mobility.

  • @The_Vampire@lemmy.world
    8•1 year ago

    Reading the study (the actual paper, not the linked article), it seems expected and sensible.

    A conjecture is that aquatic adaptation is not reversible because there are already animals on land that can out-compete animals attempting to adapt back onto land (similar to how there have been very few transitions from aquatic to land in the first place).

    Of course, in actuality this does not mean the transition from aquatic to terrestial is not reproducible, just that it would require a removal of the prohibiting factor such as a mass extinction event killing off most or all life on land.

    • danielbln
      4•1 year ago

      Well, since mass extinctions are around the corner, I guess there could be a chance! Once we’ve cooked the earth, maybe the next global apex comes from the ocean.

      • BrerChicken
        1•1 year ago

        Mass exctincrions aren’t “around the corner,” they’re just a part of life on Earth. They’ve happened several times before, and they will probably continue to happen. It’s not a coming thing–it’s the reason mammals rule the Earth right now, and why almost all life uses oxygen.

        • danielbln
          2•1 year ago

          Holocene extinction: currently ongoing. Extinctions have occurred at over 1000 times the background extinction rate since 1900, and the rate is increasing. The mass extinction is a result of human activity, driven by population growth and overconsumption of the earth’s natural resources. The 2019 global biodiversity assessment by IPBES asserts that out of an estimated 8 million species, 1 million plant and animal species are currently threatened with extinction. In late 2021, WWF Germany suggested that over a million species could go extinct within a decade in the "largest mass extinction event since the end of the dinosaurs.

          source: https://en.wikipedia.org/wiki/Extinction_event?wprov=sfla1

          • BrerChicken
            1•11 months ago

            I think you might have misunderstood me. I’m not arguing that we’re not understand one right now. I’m just saying that it happens quite frequently, in geologic time. Definitely not trying to minimize the how harmful of an impact we’re having.