Farwell forever Cambrian Explosion

marco_polo

Amazing discovery in Gabon that pushes back the date for the existence of multicelular life by an astonishing 1.5 billion years.

http://www.sciencedaily.com/releases/2010/06/100630171711.htm

The discovery in Gabon of more than 250 fossils in an excellent state of conservation has provided proof, for the first time, of the existence of multicellular organisms 2.1 billion years ago. This finding represents a major breakthrough: until now, the first complex life forms (made up of several cells) dated from around 600 million years ago.

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While studying the paleo-environment of a fossil-bearing site situated near Franceville in Gabon in 2008, El Albani and his team unexpectedly discovered perfectly preserved fossil remains in the 2.1 billion-year-old sediments. They have collected more than 250 fossils to date, of which one hundred or so have been studied in detail. Their morphology cannot be explained by purely chemical or physical mechanisms. These specimens, which have various shapes and can reach 10 to 12 centimeters, are too big and too complex to be single-celled prokaryotes or eukaryotes. This establishes that different life forms co-existed at the start of the Proterozoic, as the specimens are well and truly fossilized living material.

gbee

Gives me some credence so then, I often solved some mysteries by saying that we were probably here already and were destroyed either by natural selection, global extinction or nuclear wars.

So we might have escaped to Venus or Mars for a while, does this scenario fit the dates where Venus or and Mars could have been earth-like?

sink

gbee wrote: »

Gives me some credence so then, I often solved some mysteries by saying that we were probably here already and were destroyed either by natural selection, global extinction or nuclear wars.

So we might have escaped to Venus or Mars for a while, does this scenario fit the dates where Venus or and Mars could have been earth-like?

Whaa?

Capt'n Midnight

gbee wrote: »

So we might have escaped to Venus or Mars for a while, does this scenario fit the dates where Venus or and Mars could have been earth-like?

Venus first.
The atmosphere of Venus contains roughly the same amount of Nitrogen as ours does. Because of a lack of magnet field it's lost all the Hydrogen, enough to form an ocean 1Km deep. Venus had 90 times the pressure of our athmosphere. We would be similar if diatoms and their ilk hadn't taken the carbon dioxide released by volcanos and stored it at the bottom of the sea as limestone. In other words 2Bn years ago Venus wasn't suitable for life.

The water on Mars was lost a long time ago too.

Capt'n Midnight

What people forget is that in the kingdom of the blind the one-eyed man is King.

You can talk about oxygen transport limits and propose a very 2D organism. But it only needs to be as good as or better than it's neighbours to survive. I'm reminded of the large amphibians that used to inhabit Antarctica for so loing in roles similar to crocodiles.


Also life may have started on the planet more than once and may have been wiped out more than once !!

amacachi

Capt'n Midnight wrote: »

Also life may have started on the planet more than once and may have been wiped out more than once !!

May? I'd've thought it was more than probable.

Nice discovery, be interesting to see if it'll affect the questions in my repeat exam in a few months. :pac:

sponsoredwalk

Wouldn't this discovery either show;

a) that life can "pop into existence" pretty quickly,

b) that evolution is an extremely slow process,

c) that natural disasters can cause billion-year setbacks in the process evolution.

What I mean in c) is that Earth was relatively young back then & I'm sure the solar system was less stable with planetary debris still more prevalent and, like the Chicxulub event, would have caused speciation to take so long to finally settle (relatively speaking).

It's not such a stretch of the imagination to see that there were other microbial forms of life back then.

If you're willing to believe that thermodynamics and water played the most important role in creating replicating entities, i.e. according to the method's shown in this video, then you can see how alternative microbial entities could have formed in competition with prokaryotes.

I like that idea, but I haven't heard of much discussion on it.