Life on Earth May Have Arisen Twice, Radical Study Suggests
Radical Study Suggests Life on Earth Arose Twice
A radical new study proposes that life on Earth may have emerged not once, but twice. By analyzing the evolution of metabolic enzymes in bacteria and archaea, researchers found that these two major lineages independently developed the ability to catalyze essential reactions, suggesting they crossed the threshold from non-life to life separately. The study, published in Science Advances, challenges the traditional view of a single origin of life and could reshape our understanding of the tree of life.
Let's call it by name: we are looking at one origin of the genetic code, but two origins of life.
- randomImmigrant
The metabolic science is really cool. The conclusion that life arose twice requires you to buy that proto-cells that grew on these vents and needed those metallic surfaces to survive didn’t count as “life”.
Then, free living cells, bacteria and archea, could maybe be argued as having independent paths as they plugged the gaps in their metabolism independently. Same DNA/RNA, same proteins. Same broad rules of metabolism. Just some alternate paths through chemical space to plug in the metabolic gaps and get free from metal surfaces.
To me, these are clearly not independent paths, but rather the branching of proto-life into two of the great kingdoms of life. It’s a stretch to call this two origins rather than a branching.
Then a couple billion years later, one of em ate the other, and rather than destroy it, they both started a symbiotic relationship, and we were off to the eukaryotic race. This is all the same web of life. Not two independent streams.
- gyomu
The link the site points to seems like a better source (no ads, cites DOI etc, affiliated with AAAS rather than random aggregator website):
- andrewflnr
The headline is a little confusing. They're still talking about a "split" between bacteria and archaea, so even under this theory, the very roots of metabolism and (I'm guessing) genetic code etc still have a single origin.
Anyway, it does provide a nice reason that bacterial and archaeal cell membranes are different.
- MarkusQ
Clickbait headline.
Should be "Life left mineral substrate at least twice" or some such. The research is interesting, but they're playing word games in the telling of it by saying the most recent common ancestor of all life wasn't alive (because it was dependent on a mineral surface), but two of it's children gave rise to lineages that were.
- pingou
If true, fl in the Drake equation just got much bigger.