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Long before trees overtook the land, Earth was covered by prototaxites (2013)
281–290 of 295 posts
Re: Long before trees overtook the land, Earth was covered by prototaxites (2013)
#282Earlier quoted context omitted.
> evolutionary cohort This is a very cool idea; I haven't heard of it before, and I'm not finding much on this concept on the 'web. Anything you can point me to? :)
Large land animals only really survive in Africa, where they evolved alongside early hominids. Everywhere else they got slaughtered.
What about elephants, grizzly bears and polar bears?
Re: Long before trees overtook the land, Earth was covered by prototaxites (2013)
#283Earlier quoted context omitted.
Large land animals only really survive in Africa, where they evolved alongside early hominids. Everywhere else they got slaughtered.
What about elephants, grizzly bears and polar bears?
Wrong end of the viewscope. You're considering what's survived. Those are largely exceptions.
What's gone extinct: Virtually all of South America's marsupial megafauna (much of this prior to the arrival of humans, triggered by the rising of the central American ithsmus), mammoths, mastodons, native horses (the species was reintroduced by Europeans), giant ground sloth (Megalonyx), short-faced bears, saber-toothed cats, dire wolves, tapirs, peccaries, giant tortoises, the American lion, Miracinonyx (the American cheetah), siaga antelope, several species of llamas, Camelops (a giant camel), and more, all in North America alone. Very nearly the American bison ("buffalo") and California condor, amongst others.
In Europe there were also several species of mammoth and mastodons, native straight-tusked elephants, lions, cave bear, Irish elk, woolly rhinocerous, aurochs, and more.
Australia saw two phases of human-driven extinctions, one triggered by the aboriginies roughly 50kya, the second by Europeans, beginning about 250 years ago.
https://en.wikipedia.org/wiki/Pleistocene_megafauna>
https://en.wikipedia.org/wiki/List_of_North_American_animals...>
https://en.wikipedia.org/wiki/Australian_megafauna>
Re: Long before trees overtook the land, Earth was covered by prototaxites (2013)
#284Earlier quoted context omitted.
The time scale for new species adapted to a completely new climate is many millions of years, not a few thousands. What we destroy today won’t be replaced while humans as a species as we know it today even exists. It will always be many orders of magnitude easier to terraform Earth, even after we screwed it up, than trying to terraform Mars.
> The time scale for new species adapted to a completely new climate is many millions of years, not a few thousands. What we destroy today won’t be replaced while humans as a species as we know it today even exists. When it comes to changing climate (and some degree of pollution) instead of newly evolved adaptations you get migrations or selection for particular alleles. Adjust up and back down and you can end up wit…
Some manages to migrate or adapt. Many won’t. Either because there’s nowhere to migrate to, or because there’s no path there available. In the end, we will lose a lot of biodiversity.
Re: Long before trees overtook the land, Earth was covered by prototaxites (2013)
#285Earlier quoted context omitted.
Don’t forget all the thousands of species we’ve created ourself through agriculture! (Artificial selection) That is another important source of aligned biodiversity
None. Zero. We've created varieties, variants, races... no species. They can still interbreed.
“more new plant species in Europe have appeared than are documented to have gone extinct over the last three centuries”
https://royalsocietypublishing.org/doi/10.1098/rspb.2016.060...
From the Review article “How humans drive speciation as well as extinction”
Re: Long before trees overtook the land, Earth was covered by prototaxites (2013)
#286Earlier quoted context omitted.
What about elephants, grizzly bears and polar bears?
Wrong end of the viewscope. You're considering what's survived. Those are largely exceptions. What's gone extinct: Virtually all of South America's marsupial megafauna (much of this prior to the arrival of humans, triggered by the rising of the central American ithsmus), mammoths, mastodons, native horses (the species was reintroduced by Europeans), giant ground sloth (Megalonyx), short-faced bears, saber-toothed cat…
You're considering what's survived.
It was about what has survived
Large land animals only really survive in Africa
Re: Long before trees overtook the land, Earth was covered by prototaxites (2013)
#287Earlier quoted context omitted.
the existence of santa claus is a "belief" climate change isn't
Knowledge is just a belief that turned out to be true.
is it? I'm not so sure about that
it could also be a non-belief that turned out to be true, so that kind of shoots down that theory
yep, "belief" is definitely the wrong word to use here, "truth" or "reality" would work since climate change is true & real, and having "different beliefs" is definitely not the same thing as having your own truths and reality, which is why climate change deniers generally get mocked by people
Re: Long before trees overtook the land, Earth was covered by prototaxites (2013)
#288Earlier quoted context omitted.
> The time scale for new species adapted to a completely new climate is many millions of years, not a few thousands. What we destroy today won’t be replaced while humans as a species as we know it today even exists. When it comes to changing climate (and some degree of pollution) instead of newly evolved adaptations you get migrations or selection for particular alleles. Adjust up and back down and you can end up wit…
Some manages to migrate or adapt. Many won’t. Either because there’s nowhere to migrate to, or because there’s no path there available. In the end, we will lose a lot of biodiversity.
That's exactly my point.
Re: Long before trees overtook the land, Earth was covered by prototaxites (2013)
#289Earlier quoted context omitted.
Wrong end of the viewscope. You're considering what's survived. Those are largely exceptions. What's gone extinct: Virtually all of South America's marsupial megafauna (much of this prior to the arrival of humans, triggered by the rising of the central American ithsmus), mammoths, mastodons, native horses (the species was reintroduced by Europeans), giant ground sloth (Megalonyx), short-faced bears, saber-toothed cat…
You're considering what's survived. It was about what has survived Large land animals only really survive in Africa
First, that's an informal statement made in an online discussion forum, rather than a tightly-worded scientific assessment.
However it might be charitably interpreted along the lines of "of the prehuman megafauna extant on the multiple continents, the greatest degree of survival to the present day is found in Africa, where those species co-evolved with humans rather than experiencing humans as a suddenly-appearing invasive species".
Which is what the sources I'm familiar with generally suggest. Though not a primary source, Wikipedia reasonably summarises the situation:
Sub-Saharan Africa is the region of the world with the highest amount of Pleistocene megafauna surviving to the present day. These surviving species include the African bush elephant, African forest elephant, black rhinoceros, white rhinoceros and the hippopotamus. All of these species maintained populations in sub-Saharan Africa even after many of them were extirpated from Eurasia during the early Holocene.[58] This means that all of the largest herbivore genera present in Pleistocene Africa are still present today.
Citing:
Stuart, Anthony John (May 2015). "Late Quaternary megafaunal extinctions on the continents: a short review: LATE QUATERNARY MEGAFAUNAL EXTINCTIONS". Geological Journal. 50 (3): 338–363. doi:10.1002/gj.2633. S2CID 128868400
Stuart, Anthony J. (1991). "Mammalian Extinctions in the Late Pleistocene of Northern Eurasia and North America". Biological Reviews. 66 (4): 453–562. doi:10.1111/j.1469-185X.1991.tb01149.x. ISSN 1469-185X. PMID 1801948. S2CID 41295526
Which would strongly support the original statement by maxerickson above.
Re: Long before trees overtook the land, Earth was covered by prototaxites (2013)
#290Earlier quoted context omitted.
You're considering what's survived. It was about what has survived Large land animals only really survive in Africa
First, that's an informal statement made in an online discussion forum, rather than a tightly-worded scientific assessment. However it might be charitably interpreted along the lines of "of the prehuman megafauna extant on the multiple continents, the greatest degree of survival to the present day is found in Africa, where those species co-evolved with humans rather than experiencing humans as a suddenly-appearing in…
tl;dr?