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[rubyelf]

It cracks me up when you tell people that when bacteria first started filling the atmosphere with oxygen it was a massive crisis for all living things because oxygen is a highly reactive, toxic, corrosive, dangerous gas that reacts with almost everything it comes in contact with... and they try to tell you that you're making that up and that oxygen

Comments

[mikononyte]

Well I did not know that. So really, our oxygen usage is evolutionary and revolutionary in that we either did it or died. Hmmm. Things I did not learn in rudimentary high school science class.

Thanks! :)

[rubyelf]

Yup... oxygen was a crisis. The most primitive bacteria were all anaerobes. Oxygen was a toxic waste byproduct of some very prolific cyanobacteria.

[ragnarok_08]

Wow - this post was very enlightening :)

[theiform]

I loved this, because it told me so much I didn't have details for, but really? "Hurr durr oxygen isn't bad, we need it to live, that's stupid!" Well duh, have you never heard of evolution? The species that couldn't survive all died out and the ones that had a way to live damn well utilised it. Otherwise we, uh, wouldn't be here?

Some people.

[rubyelf]

Well, lots of organisms reacted by avoiding oxygen or just developing mechanisms to keep it out and continued using other metabolic pathways just like they had been. So it wasn't that life HAD to respond by finding a way to use oxygen... that was just a lucky trick of bacterial chemistry that led to a very efficient method of producing energy, and then some other cells captured those bacteria and made use of their tricks... all luck, a tremendous bit of luck, and why there's a good chance life on other planets never made it past the single-celled stage.

[theiform]

I getcha. My point though was that anyone who's heard of evolution should really have been able to extrapolate to "Life must have adapted to cope with what once was only toxic and destructive." Like those bacteria that live in caves where all the water is full of sulphuric acid and they have to eat the oxygen and hydrogen sulfide to survive.

Actually I just took a peek online to make sure I was getting my facts right, and it says that beneath THOSE bacteria is another layer of bacteria that can't be around oxygen and instead convert the sulphuric acid into hydrogen sulfide, so there's an example of something that just hides from the oxygen instead of making it vital there.

Also, the bacteria that eat the oxygen and sulphuric acid? Instead of making stalactites and stalagmites like mineral-rich water does in regular caves, these bacteria flowing through the water leave snottites, which are basically stalactites made of gooey bacteria instead of mineral deposits and are just as gross/cool as they sound. Also-also there is another cave

[rubyelf]

I didn't figure I'd drive people nuts with all the details. There's an excellent book called "Power, Sex, Suicide: Mitochondria and the Meaning of Life" that goes into tremendous detail about anaerobic sulfur metabolism among many, many other things.

[nimnod]

That was most satisfyingly fascinating, thank you!

[rubyelf]

You are very welcome!

[bluegerl]

Oh yummy... a lovely dose of Dawkins explained. Not that he needs much explaining but I love the way YOU do it. I get to see Oxygen dressed in weird clothes, waving a spear and a banner yelling 'REVOLUTION -KILL KILL!' teehee. And all these other molecules behaving just like a crowd of people, some saying OK lets join in stopping this ... as in "Je Suis Charlie"

And I am getting old cos my genes are committing suicide? I'm running out of ions? Dammit, so it doesn't help putting cream on my lip wrinkles????

LOVE YOU... this is BLOODY WIZARD!

[rubyelf]

Actually, cell death (and probably aging) has a lot to do with telomeres, which are bits at the end of chromosomes that protect the DNA from getting mixed up with other chromosomes or chopped off during replication. Problem is that every time a cell divides, the replication machinery has to chop off a bit of the telomere because it has to start copying somewhere in the middle, so every cell division they get shorter, and when a cell runs out of telomeres, it can't divide anymore.

[bluegerl]

So IF I should have an epitaph, I could put... 'She ran out of Telomeres.' teehee. Mine are doing pretty damn well at the moment! (is there a mitochondrial sort of superglue??) sorry am silly!

But when you think of the times a cell DOES divide in a lifetime, I'm surprised that we live so much longer than we used to. Av age 400 years ago was 42... and I'm twice that now. likely to be a lot more! And the Economic sods used to base the Pension Age at 60 because most blokes (who were the ones who earned pensions a hundred years ago) had likely died off before they got to sixty. Now...pensioners are living till 90 and 100 more and more... so the telomeres are being restuck on or are evolving to become more tenacious?

edited for spellings!

[rubyelf]

It used to be that people were likely to die of something else long before their telomeres ran out... but now they can treat so many things and keep us alive for so long! Telomeres have not gotten longer or changed their coding... it's just that the process of cells reaching the end of their lifespan is a slow, gradual process that happens across the many years of aging, and the longer we live, the more we see the effects of it.

(Free radicals can also damage telomeres. And cells that manage to develop a mutation that allows them to regenerate their telomeres have taken a big step toward becoming cancerous, because they can divide indefinitely, which our cells aren't supposed to be able to do)