New research on the Permian-Triassic extinction, Earth's most severe, reveals that even amidst widespread devastation, some marine ecosystems persisted. By analyzing brachiopod fossils from South China, scientists found evidence of thriving communities in shallow, oxygen-rich waters near land. These "oases" likely benefited from upwelling nutrients and offered refuge from the harsh ocean conditions that caused the extinction. This discovery suggests that even during catastrophic events, pockets of life can endure, offering insights into resilience and recovery.
Giant tunnels known as "paleoburrows" in South America, some exceeding a meter in diameter and tens of meters long, were likely dug by giant extinct ground sloths (specifically, scelidotheriines and mylodontines). Researchers used a variety of evidence, including claw marks, sediment analysis, and the burrows' size and shape, to rule out other potential excavators such as armadillos or humans. These immense burrows, which represent the largest ichnofossils (trace fossils) on the continent, provide insight into the behavior and ecology of these megafauna and demonstrate a unique adaptation not seen in extant sloths.
HN commenters discuss the likelihood of the giant paleoburrows being created by giant ground sloths, expressing skepticism due to the sheer size and complexity of some tunnels. Several suggest the possibility of multiple generations of sloths expanding the burrows over time, while others question the practicality of such large burrows for creatures needing to escape predators. The lack of claw marks in some sections is noted, prompting speculation about other unknown extinct creatures or even geological processes. Some commenters focus on the implications for understanding megafauna and past ecosystems, highlighting the surprising scale of these ancient burrows and the need for further investigation. One commenter humorously links the lack of clear answers to the enduring mysteries of Göbekli Tepe.
Researchers at the University of Liverpool have identified preserved collagen within a rib bone of a Lufengosaurus, a dinosaur from the Early Jurassic period. This discovery challenges the widely held belief that such soft tissue degrades completely over millions of years. The identified collagen, while fragmented, exhibits similarities to bird and crocodilian collagen, offering potential insights into dinosaur physiology and evolutionary relationships. Further analysis of this exceptionally preserved organic material may revolutionize our understanding of dinosaur biology.
HN commenters are skeptical of the "discovery," pointing out that collagen has been found in dinosaur fossils before, citing multiple examples dating back to 2007 and earlier. They question the novelty of this particular find and suggest the news is likely a misrepresentation or exaggeration of the research, possibly for publicity. Some express frustration with the cyclical nature of such announcements, while others discuss the challenges of definitively identifying ancient proteins and the potential for contamination. A few commenters offer more optimistic perspectives, acknowledging the potential value of further research on preserved collagen, particularly for understanding dinosaur physiology and evolution.
Summary of Comments ( 3 )
https://news.ycombinator.com/item?id=43408487
HN commenters discuss the Permian extinction's "oases," expressing skepticism about the study's conclusions. Some doubt the validity of characterizing small areas with slightly less devastation as "oases" during such widespread destruction. Others point out the limitations of interpreting highly localized data from millions of years ago, suggesting alternative explanations like localized geological factors or simple chance. Several commenters question the article's framing, finding it overly optimistic and potentially misleading about the severity of the Permian extinction event. A few highlight the broader implications for understanding current biodiversity loss and climate change, arguing that the study's message—that even in extreme events, pockets of survival exist—offers little comfort or practical guidance for today's conservation efforts.
The Hacker News post titled "Even the worst mass extinction had its oases," linking to an Ars Technica article about survival hotspots during the Permian-Triassic extinction event, has generated a moderate number of comments, exploring various aspects of the research and its implications.
Several commenters delve into the geological and ecological factors that may have contributed to these refugia. One commenter highlights the significance of upwelling zones, suggesting that nutrient-rich waters in these areas could have supported life even during the widespread environmental upheaval. This idea sparks further discussion about the role of ocean currents and localized environmental conditions in creating pockets of stability. Another commenter points to the study's focus on brachiopods, a type of shelled marine organism, and questions the extent to which these findings can be generalized to other forms of life.
Some comments focus on the methodology and interpretations of the research. One user questions the definition of "oasis" in this context, arguing that the survival rates, while higher than in other areas, still represent significant loss of life. Another commenter raises the possibility that the observed patterns might be due to preservation bias—that is, the fossils found in these areas might be better preserved than in other regions, leading to an overestimation of survival rates.
The discussion also touches upon the broader implications of the study for understanding past extinction events and predicting future ones. One commenter draws parallels with current environmental challenges, noting the importance of identifying and protecting potential refugia in the face of climate change. Another commenter points out the limitations of using the geological record to predict the effects of human-induced environmental changes, given the unique nature and rapidity of the current crisis.
A few commenters offer additional resources, such as links to related research papers and articles, expanding the scope of the discussion.
While the comment section doesn't contain any highly controversial or contentious debates, it provides a thoughtful and nuanced exploration of the research, highlighting both its strengths and limitations. The comments demonstrate an engaged community delving deeper into the science behind the headlines, exploring the complex factors that drive extinction and survival.