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The De-Evolution of the Ocean
An anonymous reader writes to mention an LA Times article entitled 'A Primeval Tide of Toxins.' The article looks at changing conditions in the world's oceans, and the resulting explosion in the growth of algae, jellyfish, and other primitive lifeforms. From the article: "In many places -- the atolls of the Pacific, the shrimp beds of the Eastern Seaboard, the fjords of Norway -- some of the most advanced forms of ocean life are struggling to survive while the most primitive are thriving and spreading. Fish, corals and marine mammals are dying while algae, bacteria and jellyfish are growing unchecked. Where this pattern is most pronounced, scientists evoke a scenario of evolution running in reverse, returning to the primeval seas of hundreds of millions of years ago. Jeremy B.C. Jackson, a marine ecologist and paleontologist at the Scripps Institution of Oceanography in La Jolla, says we are witnessing 'the rise of slime.'" The article is parting of a just-beginning series on our changing world called Altered Oceans.
I'm not a biologist, but why is this de-evolution? Evolution is just organism's adapting to their environment over many generations through natural selection. There have been plenty of times when simpler organism's triumphed when more complex ones failed. Take the dinosaurs for instance. Simple things like cockroaches and small rodents survived while the much larger and more complicated dinosaurs died out. Types of bacteria have been around basically forever (as far as life on the Earth is concerned).
Really, (again, I'm not a biologist) it seems like simpler organisms are generally the things that make it through massive changes in the enviornment, because the more complicated animals are too-adapted to the current condiditions and can't evolve fast enough (too long of lifespans maybe?). The exception to this might be animals (humans) that are smart enough to either adapt their enviornment to them (for better or worse), or use tools to protect themselves from that change.
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We humans are drastically changing the environment. In this century we will see mass extinction. We will also see mass adaptations and new speciation. The hardiest and most successful new species may turn out to be the bacteria and engineered organisms and ultimately nanotechnological devices that can break down and reprocess our industrial waste. Who is to say all of this isn't natural? We're 100% natural, we evolved here and we're part of this system. Whatever we do, it's natural by definition.
The question is, what do we place value upon keeping around? The polar bears, the coral reefs, the rain forests? Polar bears are cute. Have you ever walked through a forest? I'd like for my kids to be able to go diving someday...
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Disclaimer: I have a Ph.D. in chemistry but am not a marine environmental researcher.
What is happening is a massive die-off of many highly adapted species, which, directly or indirectly, depended on oceanic dissolved oxygen being higher, pH being slightly alkaline, and toxin levels being lower.
A big culprit here is phosphate and nitrate fertilizer runoff; read the series for all the details.
Re-evolution may take as long as the first time; don't hold your breath!
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Does anyone have any good recipies for jellyfish and algae?
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I'm from Williamsport, PA. At one time, that small, now drug-ridden city was called the "Lumber Capital of the World", and had the highest level of millionaires per-capita in the entire world. Unfortunately, demand for lumber rose a little faster than the trees did, and now is not the same. In 6th or 7th grade, we went out to a nature preserve (that the power plant owns - I believe the government made them due it due to all the coal pollution). He explained to us why there were so many evergeen trees in the area and not much in the way of deciduous forest. The explanation seemed pretty logical to me - Once everything in the forest was killed off by the lumberjacks, it pretty well fucked up the ecosystem. But life isn't so easily put off. First, the lesser photosynthetic life returns, ferns, small plants, etc. and so on up until you finally get pine trees, and then deciduous trees. Animal life takes just as long to return. I never saw an elk until I was probably 16 or so (I'm 20 now.), and now they actually auction off a few elk tags a year.
Once we figure out how to stop destroying our oceans, the balance will correct itself, but it will take many, many years. I kinda wonder how long until my hometown returns to it's former affluent ways (ha.).
Minor nitpick: Organisms do not evolve, populations do. Otherwise, your post is right on. The more highly adapted species (specialists) are capable of filling only very specific niches. When that niche disappears, the population either changes, or dies out. If the change to the environment/niche is very rapid, the species is unlikely to be able to adapt quickely enough, especially if they have longer life cycles and small populations (relative to, say, bacteria). Less highly adapted species (generalists) have a better chance at survival, especially if they have shorter life-spans, and larger populations (which imply greater genetic variability), as it is likely that the genes needed to survive in the new environment are already present in some sub-section of the population, and only need the chance to spread.
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Specilization for a certain environment will cause an organism to be successful as long as that environment is static. But once an environment changes, specilization becomes a very bad (=extention) thing.
There have been several mass extinction in the history of Earth. In each, the majority of species went extinct. Some of the coolest, most complex creatures can be found in the fossil record, but they died out when the environment changed.
I think humans are unique in that our increasing complexity (manifested in our brains) will cause us to survive the next mass extinction while all the other complex species die out. This is speculation, of course, but it may be just us, microbes, and plants some day.
Alternatively, we may become so powerful that we will be able to stop all future mass extinctions. That's a fantastic thought, but our current carbon-regulating attempts are the first attempt at such a feat. Building something like a giant, polarized sun-shield may be required eventually, though.
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