Home / Science / “Ten Billionths of Cosmic History”: Homo Species of the Past Failed to Survive Intense Climate Change (Weekend Feature Film)

“Ten Billionths of Cosmic History”: Homo Species of the Past Failed to Survive Intense Climate Change (Weekend Feature Film)



The human experience on our pale blue dot lasted for less than 10 billionths of cosmic history surrounded by a vast lifeless space, yet we humans congratulate ourselves, “says Peter Brannen, author of End of the world on the present reign of human beings recently called the Anthropocene – the period dating back to the atomic era of the 1950s during which human activity had the dominant influence on the climate and the environment – “on a geological heritage not acquired before we have proven ourselves capable of escaping the next century with our lives. And, moreover, most of our proudest creations – entire cities and manufactured landscapes – will be destroyed by the incessant destruction of tectonics and erosion … many of the synthetic indicators proposed to delineate the Anthropocene will not survive the insults of deep time “.

The Anthropocene – “Human Arrogance?”

“It’s human arrogance,” Brannen adds, to coin an era, the Anthropocene, which is not comparable to a geological era on par with a yawning time period like the Lower Cretaceous, an era that lasted 600,000 times longer than long of this newly minted, or the reign of the dinosaurs which lasted more than 225 million years. The Anthropocene, Brannen concludes, is an event, not an era.

“Hubris of the Anthropocene” -COVID-19 Pandemic offers a lost cosmic perspective

Past extinctions of homo species

Brannen’s conclusions foreshadow a new study – “Past extinctions of homoic species coincided with increased vulnerability to climate change” – to understand early humans’ climate preferences and how they reacted to climate change. The study shows that despite technological innovations including the use of fire and refined stone tools, the formation of complex social networks and, in the case of Neanderthals, even the production of glued-on spearheads, tailored clothing and a good quantity of cultural resources and genetic exchange with Homo sapiens, the Homo species of the past have not been able to survive an intense climate change ”, says Pasquale Raia of the University of Naples Federico II. “They tried hard; they headed for the warmer places close at hand when the weather turned cold, but at the end of the day, it wasn’t enough.

“We were surprised by the regularity of the effects of climate change,” says Raia. “It was very clear, to the extinct species and to them alone, that the climatic conditions were simply too extreme just before extinction and only at that particular time.”

Warning for humans today

Raia notes that there is uncertainty in palaeoclimatic reconstruction, in the identification of fossil remains at the species level, and in the aging of fossil sites. But, he says, the main insights “are valid under all assumptions”. The findings could serve as a kind of warning to humans today as we face unprecedented climate change, Raia says.

“It is troubling to find that our ancestors, who were no less impressive in mental power than any other species on Earth, could not withstand climate change,” he said. “And we found that just when our own species saws the branch we sit on causing climate change. Personally I take it as a thunderous warning message. Climate change has made Homo vulnerable and unfortunate in the past, and this could just happen. again “.

Extensive fossil database

To shed light on past extinctions of Homo species including H. habilis, H. ergaster, H. erectus, H. heidelbergensis, H. neanderthalensis, and H. sapiens, researchers relied on a high-resolution past climate emulator , which provides the temperature, rainfall and other data for the past 5 million years. They also examined an extensive fossil database that includes more than 2,750 archaeological records to model the evolution of the Homo species’ climatic niche over time.

Their studies offer solid evidence that three Homo species – H. erectus, H. heidelbergensis, and H. neanderthalensis – have lost a significant portion of their climatic niche shortly before becoming extinct. They report that this reduction coincided with abrupt and unfavorable changes in the global climate. In the case of the Neanderthals, things were likely made worse by competition with H. sapiens.

“Crystal Clear” – Effect of climate change

“We were surprised by the regularity of the effects of climate change,” says Raia. “It was very clear, to the extinct species and to them alone, that the climatic conditions were simply too extreme just before extinction and only at that particular time.”

Raia notes that there is uncertainty in palaeoclimatic reconstruction, in the identification of fossil remains at the species level, and in the aging of fossil sites. But, he says, the main insights “are valid under all assumptions”. The findings could serve as a kind of warning to humans today as we face unprecedented climate change, Raia says.

“It is troubling to find that our ancestors, who were no less impressive in mental power than any other species on Earth, could not withstand climate change,” he said. “And we found that just when our own species saws the branch we sit on causing climate change. Personally I take it as a thunderous warning message. Climate change has made Homo vulnerable and unfortunate in the past, and this could just happen. again “.

Source: Pasquale Raia et al. Past extinctions of homo species have coincided with increased vulnerability to climate change. One Land. Published: 15 October 2020 DOI: 10.1016 / j.oneear.2020.09.007

The Daily Galaxy, Andy Johnson via The Atlantic, Cell Press and Raia’s Lab

Top image credit: thanks to Pixabay




Source link