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← New science: ancient eukaryotes and altruistic ants

New science: ancient eukaryotes and altruistic ants - Comments

Mbee's Avatar Comment 1 by Mbee

Both articles are great. I especially liked the article about the ants 'Sick ants commit altruistic suicide'.
Information and knowledge are wonderful things. Far better than any imaginary stories that contribute nothing to our understanding of life the universe and everything.

Sat, 20 Feb 2010 15:52:00 UTC | #442604

Stafford Gordon's Avatar Comment 2 by Stafford Gordon

Darwin's insight was so beautiful in its simplicity, that it's almost unbeleivable no one had ever cottoned on to it before; and we are all, if we so choose, the beneficiaries.

Sat, 20 Feb 2010 21:05:00 UTC | #442652

prolibertas's Avatar Comment 3 by prolibertas

That was cool.

Sat, 20 Feb 2010 23:20:00 UTC | #442667

Roland_F's Avatar Comment 4 by Roland_F

Eukaryotes lived already 3.2 BYA ££
If this is really confirmed in the next years all biology books have to be re-written on the beginning.

Just last week I came along this in my Microbiology book: Prokaryotes 3.5 Billion years, Eukaryotes 1.8 billion years, so Prokaryotes nearly 2 Billion years alone.
Also a few days ago somewhere I read that the Prokaryotes might have existed already 3.85 Billion years ago based on finding in old Greenland rocks.

Well 6 days of creation can be long….

Sun, 21 Feb 2010 05:42:00 UTC | #442700

Cook@Tahiti's Avatar Comment 5 by Cook@Tahiti

And if you read Nick Lane's recent article in New Scientist, he summarises a lot of current research suggesting life didn't get started until about 2.7 billion years ago...

http://www.newscientist.com/article/mg20527461.100-first-breath-earths-billionyear-struggle-for-oxygen.html?full=true

I think the further you go back in time, the less certainty there is.

Sun, 21 Feb 2010 05:54:00 UTC | #442703

Palaeocystodinium's Avatar Comment 6 by Palaeocystodinium

My avatar is the resting spore (hypnozygote) of Palaeocystodinium bulliforme, an extinct species of dinoflagellate, - a very complex eukaryote. This 270µm long specimen is only 60 million years old, extracted from a sediment sample 3 km below the sea floor in the Norwegian Sea. The cyst wall is composed of a macromolecule of complex polysaccharides. Living dinoflagellates construct this extremely strong, acid-resistant material by polymerising their photosynthesising pigments during their motile stage. An economic strategy, they take what was expensive to make (photosynthesising pigments) and use it to make a different material that they need for their survival.

The preparation method we use to extract dinoflagellate resting spores from much younger sedimentary rock is the same as the method Javaux, Marshall & Bekker used to extract organic-walled microfossils from 3.2 billion year South African (not South American) rocks. First, we dissolve the carbonate minerals in the sediment in warm hydrochloric acid. Then we dissolve the silicate fraction of the residue in warm 60% hydrofluoric acid. What remains after this brutal treatment is acid-resistant organic material: marine phytoplankton resting spores, acritarchs (unknown affinities), pollen and spores from land plants (the latter only in rocks younger than the evolution of land plants, of course).

It is a testament to the impressive chemical resistance of the complex macromolecules that such microfossils are found in 3.2 billion year old sediments. If these are in-situ specimens, this is a very important find for palaeontology. Eukaryotes or prokaryotes, it is a wonderful discovery.

Sun, 21 Feb 2010 18:06:00 UTC | #442818

daftness's Avatar Comment 7 by daftness

Comment #462555 by Palaeocystodinium

Thanks for that.

It makes the subject more alive to get information from a scientst actively involved in research directly related to the article we are reading.

Still went whizzing over my head, though.

Mon, 22 Feb 2010 20:23:00 UTC | #443252