Man-made climate change is reportedly such a threat to the biodiversity of even just animals on earth (let alone other organic life) that species are proving to adapt too slowly to niche habitats all over the world according to a new study conducted by researchers from the University of Bath based in Somerset, UK, as well as the University of York and the Oxford University Museum of Natural History. The findings of the study, as published in Communications Biology, that rising sea levels and global warming are actually threatening to eradicate whole species very abruptly. The conclusion is that we may unwittingly be headed for mass extinction.
Scientists have found historically that, in the marine ecosystems like coral reefs where balance is particularly delicate and under constant siege, it is common for separate species to become symbiotic. This new study posits further that, in those same cases, those symbiotic species become the slowest to recover from anything that impinges on their biodiversity. The research team looked at diversity patterns and how they changed at different points along the evolutionary progression of caridean shrimps. These are the shrimps with which many are most familiar, and they’re a pillar of the marine food chain with an invaluable contribution to human fisheries as well, thereby presenting a massive vulnerability.
The team was able to model and fit an evolutionary tree for caridean shrimps — the largest ever in any study — for contrast with molecular dates and fossil dates. In so doing, they could then analyze where diversification accelerated and decelerated at various periods in the course of the last 2,000 millennia. The data they collected on that illustrates that shrimp transitioned of their own volition from marine habitats to freshwater habitats over and over, which constantly replenished biodiversity in one or the other at various times. The study cautions, though, that rising sea levels as a result of global warming might endanger this pattern.
Climate change disrupts freshwater distributions and might even yield significant extinctions. Lots of marine shrimp are symbiotic with a myriad of other animal species like sponges and corals, both of whose rates of diversification have decelerated noticeably already. Symbioses are more ubiquitous in shallow reef areas than anywhere else, yet they’re also the most threatened marine ecosystems and well known for being plagued with delicate balances. Lower diversification rates indicate caridean shrimp will recover successively more and more slowly from the foreseeable extinctions that already can’t be stopped.
The University of Bath’s Matthew Wills is an evolutionary paleobiology professor in the Milner Centre for Evolution, and he was a co-author on the published study. He says that “We are sleepwalking into a mass extinction of magnitude unparalleled since the asteroid impact that wiped out the dinosaurs. Astonishingly, we know remarkably little about the physical and biological forces that shape patterns of diversity on a global scale. For example, why are there over a million species of insects but only 32 species in their immediate sister group, the little-known remipedes?”
Mind you, the mass extinction to which Wills alluded some 2,000 millennia ago marks the broadest eradication of species in world history; it’s known as the Permian Extinction. That took out more than nine of every ten marine species along with seven of every ten land species, and to this day, no one knows why it happened, though there are several well-developed theories out there. Wills adds, “Diversity takes millions of years to evolve, but can be damaged in the blink of an eye. We are already losing diversity that has never even been documented, so it’s vitally important to understand the mechanisms that drive evolution into new species.”
There’s a new study submitted for publication in the Global and Planetary Change journal that actually puts forward the novel theory that too much coal burning was the cause of the Permian Extinction to which Wills is comparing the impending mass extinction that he and his team are anticipating. Utah State University’s Benjamin Burger studied rock layers in Sheep Creek Valley and found unexpected elements in one layer — high levels of zinc, carbon, mercury, and lead. These collectively indicate extreme coal burning, which would absolutely explain the Permian Extinction, and today, we know all about this as we attempt to curtail behaviors that would simulate exactly that because we’re avidly trying to roll back global warming’s effects. Obviously, fossil fuels (e.g. coal) are a huge part of that discussion today for the same reason.
Coal burning was always one of the many theories, but it never really took to the foreground of scientific research on the subject until now because it just lacked any real substantive evidence. The new study has yet to even be published yet, but when it comes out, it’s expected by some to make a pretty big splash, assuming methodology and results are what they sound like. The University of York’s Katie Davis was the lead author for Wills’s study, predicting a new mass extinction of colossal proportions on the same level as the Permian Extinction. She says, “Our research is important for predicting the effects of ongoing, man-made environmental change because the responses of groups in the geological past can predict their likely responses in the future. We hope our work will help us learn lessons from the last 200 million years — a different scale to that of most ecological studies.”
[researchpaper 리서치페이퍼=Cedric Dent 기자]