Scientists Decipher 3-Billion-Year-Old Genomic Fossils 217
hnkstrprnkstr writes "MIT scientists have created a sort of genomic fossil (abstract) that shows the collective genome of all life underwent an enormous expansion about 3 billion years ago, which they're calling the Archean Expansion. Many of the new genes appearing in the Archean Expansion are oxygen related, and could be the first biological evidence of the Great Oxidation Event, the period in Earth's history when oxygen became so plentiful that many anaerobic life forms may have become extinct."
Re:Wait, what? (Score:5, Interesting)
really, creationism is the 'elephant in the room' whenever you start talking about the fossil record
what I find interesting about the article is the layering effect of life. how the anerobic life got pushed out by the oxygen breathers and relegated to living in the cracks. good for us, but an extinction event for them. there have been many big extinctions, and each allowed some hardier form of live to make it to the next expansion. we are in a current extinction event (holocene), and have started to worry about an asteroid or some such wiping us out.
even that worry over our own 'extinction' bumps up against any number of religious beliefs, even if they seem to have an unrealistic timescale of tens of years, when any historical events have been separated by millions of years
so, gimmee something here, how do you discuss geologic events when people seem so driven to think in terms of their own lifespans?
Re:Wait, what? (Score:3, Interesting)
what I find interesting about the article is the layering effect of life. how the anerobic life got pushed out by the oxygen breathers and relegated to living in the cracks. good for us, but an extinction event for them. there have been many big extinctions, and each allowed some hardier form of live to make it to the next expansion. we are in a current extinction event (holocene), and have started to worry about an asteroid or some such wiping us out.
even that worry over our own 'extinction' bumps up against any number of religious beliefs, even if they seem to have an unrealistic timescale of tens of years, when any historical events have been separated by millions of years.
I'm a programmer but just happen to be reading Nick Lane's books on this. If I get something wrong please biologists jump in and correct me. :)
I only read a page or two a day (first "Oxygen", and now "Power, Sex, Suicide" - and yes, that's all based on oxygen). But the revelation I had yesterday was that anaerobic bacteria essentially drown in oxygen, just as we would suffocate with too little oxygen, which by the way is not that much below the historic percentage of atmosphere for last several hundred million years of 21%. Dropping below about 15% of atmosphere would kill all oxygen breathing life.
So anaerobic life which ruled the world didn't get pushed out by oxygen breathing life, it got pushed "out", or down into stagnant places rather, by oxygen, which was created by photosynthesis. Almost all the oxygen over .1% of the atmosphere was created by photosynthesis in plant life.
And what became of that anaerobic life in the sea with .1% oxygen? It exists to this day in our cells, which are in the same salt water of the sea in our body and exposed to .1% oxygen delivered by hameoglobin in the blood. It also exists in our intestines among other places with little oxygen, such as bottoms of swamps.
The kicker? People talk of evolution and they have no idea. All current life was set in place nearly three billion years ago. Every complex thing you ever read about in the human body cells is in every cell of every life form for almost three billion years.
DNA, RNA, mitochondria, conversion of glucose to storage of energy in ATP molecules using an extremely complex 12 step process, manufacture of the same proteins with ribosomes, fermentation to create energy without even that .1% of atmosphere oxygen when necessary (such as our muscles which fermentation kicks in when needed and creates a byproduct lactic acid which eventually causes cramps), respiration using haemin which is haemoglobin in blood and clorophyll in plants, everything was set almost three billion years ago.
Nothing has evolved, it has only specialized.
The bigger question is how this complex machinery of life developed in the first billion years of Earth amidst massive meteor impacts. People can call it what they want, but knowing that all life that has ever existed has existed essentially unchanged from three billion years ago defies explanation of "evolving" in first one to two billion years to the amazing complexity of how cells work and then staying pat for almost three billion years and only losing capabilities, not gaining new and more complex capabilities as one assumes from casual science study and reading.
I am not religious and do not consider religious arguments against evolution as anything but pedantic handwaving, but what we call evolution is really rather trivial specialization implemented by the ancient common embryo genes.
I could go on and I'm probably leaving out even more stuff that took my breath away when I read it but people have no idea the ancient universality of all life forms from the same unbelievably complex cell from three billion years ago.
rd
Re:Wait, what? (Score:3, Interesting)
The point is that this is extremely complex biochemical machinery that is mind boggling to even imagine how this somehow came together.
I am more inclined to think it came from space than anything.
How would that make it less mind-boggling? It just relocates the problem. Does it somehow make more sense to think that life had a few billion more years to evolve on some other planet than just 1.5 billion years here on earth? I'm not trying to be pedantic here, I'm genuinely curious as to how you'd think "space" is a better explanation...