8 ms·

Freshwater animals aren't really relevant since they aren't going to do any good for life in the ocean if the animals that evolved for PH of 8.1 can't survive d

Freshwater animals aren't really relevant since they aren't going to do any good for life in the ocean if the animals that evolved for PH of 8.1 can't survive due to decreasing alkalinity. If the ocean life can't adapt it very well could be a harbinger of the apocalypse. Not saying it will, but your assertion that it isn't is also a false bromide.

Mikeb85 7y ago
I'm going to go out on a limb and say that since life has existed on earth for quite some time, through changing conditions (CO2 levels were far, far higher at one point in earth's existence!) and in many different biomes, life will continue to exist. In fact, I wouldn't be surprised if in ~20 years we find that these crabs, through natural selection, manage to keep their shells or adapt through some other means.
- ericd 7y ago
  The amount of time given to adapt to those changes seems likely to have a big effect on how well organisms weather them... just because the same conditions existed x million years ago doesn’t mean that life can deal with it if the same change happens over 100 years.
  - quakeguy 7y ago
    The rate of ecological collapse far outpaces most organisms ability to evolve.
    - Mikeb85 7y ago
      Does it? Normally I hate to be the guy to ask for some sort of citation but on this subject, all I hear is doom and gloom yet none of the dire predictions ever come to fruition.
      - srmatto 7y ago
        Aren't we currently living through a mass extinction? That seems like a reasonable proxy for "outpaces most organisms ability to evolve." https://en.wikipedia.org/wiki/Holocene_extinction https://en.wikipedia.org/wiki/Holocene_extinction
        Mikeb85 7y ago
        That article defines a "mass extinction event" as 75% of species dying off within a specific timeframe, but then goes on to say that 50% of species might be extinct by the end of the century. Later it says 7% of species have gone extinct. Far cry from 75%.
        gizmo686 7y ago
        The end of the centuary is only 80 years away, or ~4 human gereations. There are humans alive today that will experience it. In geological time, that is practically nothing. The artivle you are refring to also says that the current rate of extinction is 10-100x that if previus mass extinctions. Unless you have some reason to believe we will manage to stop the ongoing ectinction event, then it will be a mass extinction by the time it is done; hence saying that we are in it.
        abathur 7y ago
        What kind of timeframe do you imagine they mean?
- empath75 7y ago
  There have been times when almost all life on earth died out. So like, yes we will continue to having living things on earth probably until it's swallowed by the sun, but that doesn't mean that it will remain habitable for any of the species that currently live here, including ourselves.
- Johnny555 7y ago
  It's true that life has existed for a long time and survived a number of mass die-offs, but humans have only been around for a tiny sliver of that time. So yeah, it's unlikely that humans could kill off all life on earth even if we keep trying to do so, but it's certainly possible that they'll cause their own destruction. I think it's unlikely that human activity will lead to mass die-offs (of humans, we're already in a mass extinction event of animals) but our children and grandchildren may be in for a big lifestyle change.
- CalRobert 7y ago
  "Life" will, but then this statement would have given false comfort to organisms watching the coming Oxygen catastrophe.
- jknoepfler 7y ago
  Earth has also undergone at least five mass extinction events that killed between 70-98% of life on the planet. Rapid changes in atmospheric conditions are not friendly to life. Life is not robust or particularly adaptable at the species level, or on non-geological timescales.
- btilly 7y ago
  You went too far on that limb. The ocean Ph level doesn't have much to do with CO2 levels. It has everything to do with the rate of change of CO2 levels. If you raise the CO2 level fast, the ocean turns acidic. If you raise it slowly, deposits of lime on the bottom of the ocean dissolve and Ph remains constant. While CO2 has been much higher than the present, the rate of change is unprecedented. Also evolution is a lot slower than you think. A change in Ph over millions of years could readily be adapted to by evolution. Over 20, not so much.
  - Mikeb85 7y ago
    Evolution through natural selection happens much quicker than that. Sure, fish walking on land progression takes awhile, but otherwise it's pretty quick. https://www.sciencemag.org/news/2019/05/evolution-brings-extinct-island-bird-back-existence https://www.sciencemag.org/news/2019/05/evolution-brings-ext... As for the crabs, some of them still develop hard shells. They'll reproduce and the soft-shelled ones won't. So whatever it is that causes harder shells will persist.
    - btilly 7y ago
      Evolution has a fast mode and a slow mode. The fast mode is that if there is enough genetic diversity in the population that a subset have a combination of traits that suffices, natural selection quickly will reduce the genetic diversity and all of the survivors will have those traits. The advantage of sexual reproduction is that much of the genetic diversity is retained and gets to recombine in interesting ways allowing the next challenge to be addressed. The slow mode is that if overcoming a barrier requires random mutations to produce new traits, it takes many generations for that to happen. The current pH allows some to survive and others not to. But with projected future pH levels, none will be able to survive. Therefore natural selection will select out the entire population as there isn't enough time for a new set of traits to evolve.
  - achillesheels 7y ago
    What about nylonase?
Andrew_nenakhov 7y ago
Life on Earth had survived many much more dramatic events. Some had caused mass extinctions, but those organisms that survived soon captured the planet and thrived in a vacated environment. What I'm really worried about is that future brings us much more severe issues to deal with, which no multicellular life can survive. [1] The problem is quite urgent, and we only have 500M-1B years to deal with this. [1]: https://en.m.wikipedia.org/wiki/Timeline_of_the_far_future https://en.m.wikipedia.org/wiki/Timeline_of_the_far_future
hinkley 7y ago
In theory you are right, in practice threatened and endangered species may not have the population diversity for selective pressure to outpace population decline.

Mikeb85 7y ago

I'm going to go out on a limb and say that since life has existed on earth for quite some time, through changing conditions (CO2 levels were far, far higher at one point in earth's existence!) and in many different biomes, life will continue to exist. In fact, I wouldn't be surprised if in ~20 years we find that these crabs, through natural selection, manage to keep their shells or adapt through some other means.

ericd 7y ago
The amount of time given to adapt to those changes seems likely to have a big effect on how well organisms weather them... just because the same conditions existed x million years ago doesn’t mean that life can deal with it if the same change happens over 100 years.
- quakeguy 7y ago
  The rate of ecological collapse far outpaces most organisms ability to evolve.
  - Mikeb85 7y ago
    Does it? Normally I hate to be the guy to ask for some sort of citation but on this subject, all I hear is doom and gloom yet none of the dire predictions ever come to fruition.
    - srmatto 7y ago
      Aren't we currently living through a mass extinction? That seems like a reasonable proxy for "outpaces most organisms ability to evolve." https://en.wikipedia.org/wiki/Holocene_extinction https://en.wikipedia.org/wiki/Holocene_extinction
      - Mikeb85 7y ago
        That article defines a "mass extinction event" as 75% of species dying off within a specific timeframe, but then goes on to say that 50% of species might be extinct by the end of the century. Later it says 7% of species have gone extinct. Far cry from 75%.
        gizmo686 7y ago
        The end of the centuary is only 80 years away, or ~4 human gereations. There are humans alive today that will experience it. In geological time, that is practically nothing. The artivle you are refring to also says that the current rate of extinction is 10-100x that if previus mass extinctions. Unless you have some reason to believe we will manage to stop the ongoing ectinction event, then it will be a mass extinction by the time it is done; hence saying that we are in it.
        abathur 7y ago
        What kind of timeframe do you imagine they mean?
empath75 7y ago
There have been times when almost all life on earth died out. So like, yes we will continue to having living things on earth probably until it's swallowed by the sun, but that doesn't mean that it will remain habitable for any of the species that currently live here, including ourselves.
Johnny555 7y ago
It's true that life has existed for a long time and survived a number of mass die-offs, but humans have only been around for a tiny sliver of that time. So yeah, it's unlikely that humans could kill off all life on earth even if we keep trying to do so, but it's certainly possible that they'll cause their own destruction. I think it's unlikely that human activity will lead to mass die-offs (of humans, we're already in a mass extinction event of animals) but our children and grandchildren may be in for a big lifestyle change.
CalRobert 7y ago
"Life" will, but then this statement would have given false comfort to organisms watching the coming Oxygen catastrophe.
jknoepfler 7y ago
Earth has also undergone at least five mass extinction events that killed between 70-98% of life on the planet. Rapid changes in atmospheric conditions are not friendly to life. Life is not robust or particularly adaptable at the species level, or on non-geological timescales.
btilly 7y ago
You went too far on that limb. The ocean Ph level doesn't have much to do with CO2 levels. It has everything to do with the rate of change of CO2 levels. If you raise the CO2 level fast, the ocean turns acidic. If you raise it slowly, deposits of lime on the bottom of the ocean dissolve and Ph remains constant. While CO2 has been much higher than the present, the rate of change is unprecedented. Also evolution is a lot slower than you think. A change in Ph over millions of years could readily be adapted to by evolution. Over 20, not so much.
- Mikeb85 7y ago
  Evolution through natural selection happens much quicker than that. Sure, fish walking on land progression takes awhile, but otherwise it's pretty quick. https://www.sciencemag.org/news/2019/05/evolution-brings-extinct-island-bird-back-existence https://www.sciencemag.org/news/2019/05/evolution-brings-ext... As for the crabs, some of them still develop hard shells. They'll reproduce and the soft-shelled ones won't. So whatever it is that causes harder shells will persist.
  - btilly 7y ago
    Evolution has a fast mode and a slow mode. The fast mode is that if there is enough genetic diversity in the population that a subset have a combination of traits that suffices, natural selection quickly will reduce the genetic diversity and all of the survivors will have those traits. The advantage of sexual reproduction is that much of the genetic diversity is retained and gets to recombine in interesting ways allowing the next challenge to be addressed. The slow mode is that if overcoming a barrier requires random mutations to produce new traits, it takes many generations for that to happen. The current pH allows some to survive and others not to. But with projected future pH levels, none will be able to survive. Therefore natural selection will select out the entire population as there isn't enough time for a new set of traits to evolve.
- achillesheels 7y ago
  What about nylonase?

Andrew_nenakhov 7y ago

Life on Earth had survived many much more dramatic events. Some had caused mass extinctions, but those organisms that survived soon captured the planet and thrived in a vacated environment. What I'm really worried about is that future brings us much more severe issues to deal with, which no multicellular life can survive. [1] The problem is quite urgent, and we only have 500M-1B years to deal with this. [1]: https://en.m.wikipedia.org/wiki/Timeline_of_the_far_future https://en.m.wikipedia.org/wiki/Timeline_of_the_far_future

hinkley 7y ago

In theory you are right, in practice threatened and endangered species may not have the population diversity for selective pressure to outpace population decline.