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Microbes Likely Abundant Hundreds of Meters Below Sea Floor
sciencehabit writes "Samples drilled from 3.5-million-year-old seafloor rocks have yielded the strongest evidence yet that a variety of microorganisms live deeply buried within the ocean's crust. These microbes make their living by consuming methane and sulfate compounds dissolved in the mineral-rich waters flowing through the immense networks of fractures in the crust. The new find confirms that the ancient lavas formed at midocean ridges and found throughout deep ocean basins are by volume the largest ecosystem on Earth, scientists say."
Possible, but more likely that it branched away from another more abundant form, filled a niche in and was pretty much forgotten about by everything else. Not to say that it couldn't well be an exceptionally early form that simply never changed.
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Latter option is pretty unlikely. Even microbes have their predators and parasites (usually in form of various viruses), so they have an arms race for survival of the fittest not that different from one we have here on the surface. It's highly unlikely for any single life form to survive billions of years largely unchanged by this process, as at some point your predators and parasites would optimize themselves to the level where you will get either wiped out entirely or severely weakened so that competing life forms will occupy your biological niche.
Or occupy a niche that is bitchin hard for predators to get at you in.
Not even close. They may possess some similarities to the first cellular life forms which were almost certainly also chemovores (though likely lived in amino-acid rich muck on the bottom of shallow seas), but these organisms have been evolving for four billion years since then - they are every bit as evolved as humans, arguably far more so since their generations are so much shorter. They simply spent more time optimizing for a particular ecosystem niche whereas our ancestors kept changing directions dramatically. I mean come on - living in giant clonal colonies of billions of specialized individuals? Clearly a fad. It'll last a few billion years more, tops.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I wish one of these bugs would occupy Wall Street. Now there is a place conspicuously lacking in any meaningful predation characteristic of a healthy ecosystem.
Stay sentient. Don't drink bad milk.
This isn't new: Recommend Professor Robert Hazen's book on the origins of life. He says no matter where you go on earth, deep into sea sediments or the rock of deep undergrounds mines, every cubic inch of the Earth is teaming with microbes. Worth noting the vast majority of them are indifferent to you. Even out of the ones that made their home on your body (for every cell on your body there are 10 bacteria along for the ride), the vast majority of those are indifferent or even beneficial. Only a tiny percentage are pathogenic, and often only when your immune defences are down. On the origins of life it isn't that it is hard to come up with an explanation, but instead there are so many plausible theories they don't know which one it might have been. It may be far easier for life to get started than we like to think. http://www.smithsonianmag.com/science-nature/The-Origins-of-Life.html
On Earth where ever life can survive it does and generally thrives. It just proves how tenacious and adaptable life is in the Universe. There are only really two options, life is an unlikely fluke or it's everywhere it can possibly exist. Life may be more pervasive than anyone thought possible. The dogma has been that where life is possible it's still rare but the more likely truth is systems where like can exist but doesn't may be the rare exceptions.
Indeed. In fact sunlight was probably largely irrelevant to Earth life for most of the first billion or so years it existed. Prevailing opinion is now that chemical energy from hydrothermal vents was probably the primary "food" early on, then eventually perhaps each other. Which makes sense if you think about it - complex chemistry would probably find chemical energy far more accessible than capturing radiation. Photosynthesis doesn't appear to have really caught on until much later, with the evolution of chlorophyll likely causing the first mass extinction event as it flooded the seas and atmosphere with toxic oxygen.
Of course Europa is a much smaller petri dish than Earth, and less energetic, so I'd suspect life would evolve much more slowly. If we do find life there, and it's anything like us (DNA, etc), it might provide a fascinating glimpse into what primitive life on Earth may have be like. Everything here on Earth is the product of around 4 billion years of evolution.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Shut your yap yah overgrown building block, I'd like to see you stop meEeep.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
In truth there are no "higher" life forms, just those more like us. Darwin himself took great pains to avoid concepts like "higher" or "lower", rather "suitability to environment" is the only meaningful yardstick, with adaptability being one factor in that when you consider the long-term.
Evolving doesn't imply any sort of direction, it's a path function. You could make a good argument for measuring it in terms of either gross or net changes from some historical reference point - in terms of a wiggly line on paper either the distance along the line or the distance between the endpoints. But to measure against some arbitrary characteristics that we possess is to draw a random straight line from the shared starting point and say "only distance in this direction matters", an extremely egocentric claim that would need some substantial justification. A perhaps more justifiable arbitrary line might be genome size, after all that's probably somewhat related to path length, and by that measure we're on par with corn, and have been beaten out by several other organisms, including I believe several bacteria and I think even some super-viruses.
I claim bacteria may be more evolved than us because each subsequent generation takes one step along that path, and bacteria have had thousands of times more generations than us in their history. Of course sexual reproduction allowed us to potentially take larger steps, but on the other hand bacteria still practice direct gene exchange so newly evolved "desirable" traits can potentially spread through the population in a single generation, and even between different species. And while I'm not certain as to the exact mechanism I would bet good money that there is some level of "choice" in gene transfer rather than being a purely random exchange (anyone with more definite knowledge care to chime in?), which would mean that synergistic gene combinations could reasonably be expected to accumulate far more rapidly - in essence they've been performing chimeric genetic engineering on themselves on a regular basis for four billion years, even if they're probably not too bright about it (on the other hand any incremental increase in the instinctual/chemical "intelligence" involved in the process would probably confer an *extreme* evolutionary advantage, so they might actually be incredibly "smart").
--- Most topics have many sides worth arguing, allow me to take one opposite you.