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sn1987a
02-03-2017, 10:28 AM
https://www.youtube.com/watch?v=rynHqD3Elow

graham.hobart
02-03-2017, 11:31 AM
This is very interesting.
Just read a very good book on the Cambrian Explosion by Erwin and Valentine and it delves into Ediacaran and Cryogenian evidence for multicellular life.
It also looks at genetic and biochemical environmental changes which may have allowed life to diversify-including changing O2 and carbon levels and Redox changes in biofilms with phosphate and iron reactions.
Certainly molecular clocks hint at a number of shared genes which have the basics for complex life going way back into 700MA territory.
There are a number of simple microbes today that still have the genes for bilateral symmetry and triploblastic development including basic muscle and nerve tissue- this is hints at a common ancestor to all way before the Cambrian explosion of body plans/crown phyla. There are suggestions that some species actually simplify body plans and turn off genes to evolve more adaptability to niche environments.
Some of the deep biology was a bit intricate but it's a damn good read and nicely illustrated with fossils and art work. :thumbsup:
Graz

traveller
02-03-2017, 12:11 PM
Speaking of which, very disappointed with the BBC and their sloppy illustration

gary
02-03-2017, 01:08 PM
Hi Barry,

There is an article today in the Sydney Morning Herald by Science Editor, Marcus Strom,
with the heading "Controversy over Nature magazine claims world's oldest fossils have been found".

Story here :-
http://www.smh.com.au/technology/sci-tech/controversy-breaks-out-over-claims-that-worlds-oldest-fossils-have-been-found-20170301-gunu0j.html

sn1987a
02-03-2017, 01:35 PM
Ha! thanks Gaz, so science then! :lol: I met some of those guys a million years ago and was wondering what their take on it all was.

Two good things, they'll all try harder and WA still has the oldest in the world confirmed :P

gary
04-03-2017, 02:55 PM
20 years ago, when they discovered what they thought might be four-billion
year old bacteria-like fossils in the Martian ALH84001 meteorite which
was found in Antarctica, the lead NASA investigator, David MacKay,
who was Chief Scientist for astrobiology at the Johnson Space Center,
gave a talk at Sydney University.

I had the opportunity to chat briefly with McKay after the talk and
congratulate him that if his findings turn out to be true, it would be
arguably the greatest scientific discovery of all time.

He was quite humble but gave a smile. The scientific and philosophical significance
of such a discovery was not lost on him. :)

Unfortunately, after further investigation, the consensus view was that these
were not extra-terrestrial fossils.

But it was exciting at the time.

Background on AH84001 -
https://en.wikipedia.org/wiki/Allan_Hills_84001