Extra-Terrestrial life: what type of life?

The non amateur stuff. Hawking, black holes, that sort of thing

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brian livesey
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Extra-Terrestrial life: what type of life?

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On our own planet Earth, all life is carbon-based. Some years ago, there was an hypothesis/theory circulating that considered whether there’s life in the universe that’s silicon-based. In recent years, the idea seems to have been dropped, with carbon reasserting itself.
If ET is carbon-based, we’d expect it to have formed in a watery environment of some sort, and be subjected to similar natural selection pressures as Earth’s life.
An important discovery has very recently been made in Scotland of the oldest known multicellular organism.It’s in an excellent state of fossil preservation and suggests that evolution from single cells to multicellular cells began at least a billion years ago, and in fresh water rather than in the ocean. This contrasts with another recent theory that single ( if not multicellular ) cells may have begun in chemical-rich geothermal springs.
Professor Charles Wellman at Sheffield University said: “The origins of complex multicellularity and the origin of animals are considered to be the two most important events in the history of life on Earth. Our discovery sheds new light on both of these.”
The fossil was discovered at Loch Torridan in the north-west Highlands.
We are told that in the beginning there were two types of cells. One type had a nucleus, but no surrounding mitochondria ( for energy ). They second type of cell had mitochondria but no nucleus. At some point, one of each type fused. The new cell divided exponentially and gave us the multicellular life,in all its variety, we see today.The boffins say it only happened once that two primitive cells fused together. We can only wonder how many exo-planets have travelled down the same road of evolution to life.
Last edited by brian livesey on Wed May 05, 2021 1:18 pm, edited 1 time in total.
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Re: Extra-Terrestrial life: what type of life?

Post by SkyBrowser »

brian livesey wrote: Tue May 04, 2021 5:32 pm suggests that evolution from single cells to multicellular cells began at least a billion years ago
I thought it was already known that multicellular organisms evolved well before one billion years ago??? E.g. cyanobacteria ("blue-green algae") that have been found in rocks over 3 billion years old. Or is the new discovery a eukaryote rather than a prokaryote?
brian livesey
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Re: Extra-Terrestrial life: what type of life?

Post by brian livesey »

I’m only a general reader Skybrowser, so I can’t answer your query. I just stated what was in the press article, but not verbatim, except between quotation marks.
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