Uncommon Descent Serving The Intelligent Design Community

Researchers: Eukaryotes got started from a merger between bacteria and archaea, without oxygen


Because otherwise, the timing doesn’t work:

Since the 1960s, many scientists have argued that the emergence of eukaryotes — cells containing a clearly defined nucleus — happened in response to the oxygenation of Earth’s surface environment. But new research led by Stanford University and University of Exeter scientists suggests eukaryotes in fact emerged in an anoxic environment in the ocean.

“We can now independently date eukaryogenesis and key oxygenation transitions in Earth history,” said lead author Dr. Daniel Mills, a researcher in the Department of Geological Sciences at Stanford University, the Department of Biology at Portland State University, and the Penn State Extraterrestrial Intelligence Center.

“Based on fossil and biological records, the timing of eukaryogenesis does not correlate with these oxygen transitions in the atmosphere (2.22 billion years ago) or the deep ocean (0.5 billion years ago).”

News Staff, “Eukaryotic Cells Emerged in Anoxic Environment, New Study Suggests” at SciNews (April 27, 2022)

So, on this view, complex life started as a merger (symbiosis) between the simplest life (Archaea) and bacteria:

“Mitochondria-bearing eukaryotes likely resulted from a merger between archaea and bacteria, and the DNA in modern Asgard archaea is more closely related to the DNA found in eukaryote nuclei today than it is to other archaea.”

“This is additional evidence that the host that took in the bacterium was an archaeon.”

News Staff, “Eukaryotic Cells Emerged in Anoxic Environment, New Study Suggests” at SciNews (April 27, 2022)

On the whole, it might be easier to conclude that the timing is somewhat off than that complex life started without oxygen. But symbiosis is an intriguing theory nonetheless.

The paper requires a fee or subscription.

You may also wish to read: Claim: Complex cells started without oxygen Yes, the ham sandwich was invented that way too. It started without any ham… (The University of Exeter’s take on the story)

Although not too germaine to the discussion, I just came across this and didn't see any UD coverage on it yet. "Potentially Alive 830-Million-Year-Old Organisms Found Trapped in Ancient Rock* MICHELLE STARR 16 MAY 2022 _Excerpts:_ And living prokaryotes have been extracted from halite dating back 250 million years;... _could it be conventional dating results aren't properly interpreted and it's actually much, much younger?_ .....why not 830 million? _laws of physics, chemistry, known biological decay rates_ Possible survival of microorganisms over geologic time scales is not fully understood," the researchers wrote. _if you insist on Myo, but it's much easier to understand if the organisms are only thousands of years old, buried by the Genesis flood_ It has been suggested that radiation would destroy organic matter over long time periods, yet Nicastro et al. (2002) found that buried 250 million-year-old halite was exposed to only negligible amounts of radiation. _or, the negligible radiation dose could indicate rather_ *a negligible time elapsed,* _roughly .000005% of the conventional dating_ Article: https://www.sciencealert.com/830-million-year-old-microorganisms-found-trapped-in-australian-rock solemn existence
To slightly misquote Fasteddious, (from an earlier post of his) “ Saying “the emergence of eukaryotes DID NOT happen in response to the oxygenation of Earth’s surface”, is like saying, “the emergence of airplanes DID NOT happen in response to the arrival of humans on Earth”. It may be true but tells you nothing about how it happened. Some scientists like to dance around the margins of evolution without addressing any actual natural processes. Then they pretend that they have added to our knowledge about evolution. (“evolution” is used here as changes in lifeforms over mega-years, rather than as “natural, Darwinian-like processes”.)” All that has happened is that oxygen has been removed as a contributing mechanism to the appearance of eukaryotes. The mechanism is as obscure as it ever was. Belfast

Leave a Reply