At https://phys.org/news/2020-08-ancient-genomes-woolly-rhinos-extinct.html … ancient genomes suggest the woolly rhinocerus went extinct due to climate change – not from overhunting. On the face of it, this seems to be another article in the long running saga between those who believe humans were responsible for the extinction of large herbivores in Siberia and N America and those who claim climate change played an important and decisive role. The latter has in latter years become attached to the global warming/climate change hype but was not originally mixed up in climate science. There was a distinct case for climate change at the end of the Ice Age long before certain politicised scientists decided to highjack climate as a tool for change in society. They were challenged by the equally insistent group that believe humans are the scourge of life on earth and are to blame for all its woes. In other words, both sides of the coin are not a lot different from your average climate change alarmist and malthusian. For serious scientists this represents a dilemma and this article has run into the buffers as a result of having to choose between one and the other as no other explanation is part of the mainstream mantra – least of all, catastrophism, in any shape or form.
A study in Current Biology this month, has found, by sequencing the DNA of woolly rhino remains, that the population of these rhinocerus was stable and diverse right up until just before they disappeared. It was initially thought by researchers, it says, that humans were to blame for their disappearance. However, it is now known that humans were living in northern Siberia at least as early as 30,000 years ago. This implies these animals were able to cope with humans in the vicinity and any hunting activities were not great enough to cause a blip in their numbers and genetic diversity. The authors, on the basis of that evidence, conclude that humans could not have been responsible for their demise. Some other factor pushed them over the top – and that could only have been climate change from a mainstream perspective. So, once again, one point of view is being pushed against the other, but does it have to be that way. What is more obvious is that the genetic data only goes up to 18,500 years ago, the end of the Late Glacial Maximum (hereafter LGM). The LGM is followed by what is called the Oldest Dryas event, which was also cold but not universally as cold as the LGM. Hence, the authors of the article conclude that as woolly rhinos, like woolly mammoths, were adapted to a cold climate they could not have died out at this point in time but their demise must have occurred in the following Bolling-Alleroed warming period. The thinking here seems to be that woolly mammoths were not equipped to deal with temperatures that were significantly warmer than in the Ice Age and the Oldest Dryas. Ths is the achilles heel that will allow the opposite side in the mainstream blame machine to resurrect the humans did it idea, with a vengeance. Why would rhinocerus not be able to adapt to warmer weather. Evolution would suggest they were capable of shedding their hairy coats just as easily as they developed them in the first place, when living on the Tibetan Plateau.
We have another assumption, perhaps, that woolly rhinos did not die out at the Oldest Dryas but lived for a thousand years or longer afterwards, into the warming phase. Don't know if they can prove this but they did not have any remains to take a genome sample from so perhaps they did die out in the colder event. Some of them may have survived until the Younger Dryas event which saw a mass die-off of woolly mammoths and other herbivores. One can imagine a mass die-off at the Oldest Dryas too as there are distinct similarities between the two periods (hence the common designation of dryas, a flowering plant adapted to near Arctic conditions). The designation originates from researchers in Scandinavia and the dryas events can be distinguished from the LGM as in the latter an ice sheet covered Sweden and Norway (and surrounding regions) in which no flowering plant was able to grow. In other words, the dryas episodes had a varied climate – both warm and cold but with an average cooler than the warming period that followed. If there was a common origin for all these dryas events, as there was a shortish Older Dryas event dividing the Bolling from the Alleroed warming phases, ti can hardly have been climate change alone – and some other vector must be involved. The idea that woolly rhino died out in a nice warm climate is hardly convincing as warm allows plants to grow = more food for herbivores to consume.
Now, if there was a series of catastrophic events, of some kind, responsible for the dryas events, the new evidence gleaned by the researchers could be interpreted somewhat differently. We are looking for a cause of mass die-offs (not necessarily extinctions as some herbivores survived, such as horses and bison and musk oxen). A recurring catastrophic encounter between the earth and a cosmic object (or debris left behind by a cosmic object) might be one explanation – but this is an open question. Not the subject of this commentary.
At https://wattsupwiththat.com/2020/08/13/ancient-genomes-suggest-woolly-rh… … which comes complete with a hat full of comments. The same people, mostly, that were vocally anti-catastrophist on the recent Younger Dryas was caused by a volcano study posting emerge on the this thread as championing the human overkill theory. Barmy. It is clear this was a serious piece of research and their findings, as far as the DNA is concerned, is top notch. It is also clear from other DNA research that during the LGM there was a lot of humans living in Siberia – some of whom migrated into the Americas. At the end of the LGM, as temperatures became colder in Siberia and warmer in northern Europe, humans moved from Siberia to colonise previously glaciated regions. They expanded in both directions. No doubt human numbers also declined, along with those of herbivores, at the boundary of the Oldest Dryas, just as they did at the boundary of the Younger Dryas, around 5000 years later. The interesting point here is that if northern Siberia was able to support not only humans but large herbivores there must have been considerably more vegetation than occurs within a tundra system. One of the comments even refers to a Russian study that claimed woolly mammoths did not live on a tundra habitat but in larch woodland. That makes sense as elephants feed on tree parts. In the modern world larch grows in cooler habitats than temperate forest, and at altitude on mountain ranges such as the Carpathians in central Europe. They dominate boreal forest across Siberia and Canada, a zone situated below the modern tundra.
The big question left unsaid is in what manner did the herbivores die. Was it in mass killings with lots of bone heaps or are we dealing with single animals. Is there any evidence of catastrophism such as mass burials of herbivores, mixed up swith broken trees and vegetation. One of the commenters makes the point that mainstream opinion is that tundra during the Ice Age was in some way magically different to tundra in the modern world, a theory that seems to have stuck in the minds of some students (even when they are adults). If tundra contained lots of grasses rather than moss and sedges it would not amount to tundra. It was a different kind of habitat. Mainstream, while recognising that research has shown Siberia was not glaciated, still think in terms that it was bitterly cold. No doubt it was cold – but it was also warm enough for large herbivores to browse and feed and expand in numbers. Large herds of bison, horses, and mammoth, as well as rhinocerus, require lots of vegetation in order to feed themselves. Some animals, such as musk oxen, live in cold environments in the modern world – so we are not talking about warm as in warm and pleasant but warm as in not glacial or bitterly cold. Quite unlike modern northern Siberia. Not only that but the Pleistocene herbivores were much larger than their modern equivalents. They required even more vegetation in order to thrive. One might suggest a mixture of boreal forest and steppe habitat.
It is worth pointing out than in early to mid Holocene Siberia was warmer than it has been from mid to late Holocene. This seems to explain the survival of mammoth in locations such as Wrangel Island. They became dwarf mammoths, attributed to their island location and a dearth of vegetation. They seem to have survived, albeit in small numbes, down to around 3000BC. Why this should be so is not fully understood. The implication is that climate deteriorated around 3000BC, or they were hunted down by humans. There is evidence of a 200 year cooling episode at this time, the so called Piora Oscillation. Again, what was the vector for that long cooling episode?
Whatever occurred at the Oldest and Younger Dryas periods it was not drastic enough to kill off horses and bison and musk oxen etc. We also have to take into account mass die-offs of animals around 40,000 years ago, preceding and leading up to the LGM. The dates here are skewed by C14 plateaus that the new IntCal20 calibration will not resolve. That was perhaps not the plan. IntCal20 will keep the C14 laboratories in universities solvent for a some time even though new forms of dating, and perhaps cheaper, are catching up with them.
If we were to link all these events to a sudden onset of cold weather rather than warming, the modern obsession, one could imagine the woolly rhino demise coincided with the Oldest Dryas event. Warmth is an unlikely killer. No doubt there will be a revival of the human hunting theory, a certainty when one reads some of the comments at WattsUp.