Such an event, if it transpired on Earth today, would see kilometres-thick ice sheets gouging their way from the Arctic to the Bahamas. Once-diverse ecosystems and climate zones would merge into a single, uniform condition, seemingly destined to be barren. Scientists once argued that such a 'snowball' state could never have existed on Earth since global glaciation could not be reversed. Moreover, on such a world, all life, including our own ancestors, would surely have been extinguished.
Mold is a perennial scourge in museums that can disfigure and destroy art and artifacts. To keep this microbial foe in check, institutions follow protocols designed to deter the familiar fungi that thrive in humid settings. But it seems a new front has opened in this long-standing battle. I'd recently heard rumblings that curators in my then home base of Denmark have been wrestling with perplexing infestations that seem to defy the normal rules of engagement.
Eukaryotes drastically differ from archaea and bacteria (collectively, prokaryotes) by the complex organization of eukaryotic cells. The signature features of this organizational complexity include the eponymous nucleus, the endomembrane system, the elaborate cytoskeleton and the energy-converting mitochondrion, which evolved from an alphaproteobacterial endosymbiont9. Thus, the last eukaryotic common ancestor (LECA) probably already possessed mitochondria along with the other signatures of the eukaryotic cellular organization.
It's a plant! It's a fungus! It's... an entirely new type of lifeform hitherto unknown to science? That appears to be the case for a puzzling, spire-shaped organism that lived over 400 million years ago, according to a new study published in the journal Science Advances. After analyzing its internal structures, the authors argue that the mystifying ancient beings known as prototaxites don't belong to any of the existing biological kingdoms.