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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.
It's funny when people claim that things are evolving into "higher" or "lower" forms, as if people are the obvious pinnacle of the process.
What's happening is that the rate of change in the environment is faster than many species can keep up. When you have 10,000 individuals in a population and they breed every 5 years, they can only "absorb" so much change. When you have a species that has billions of individuals and reproduce every 20 minutes, they can take massive environmental change and thrive in it.
The genetic diversity in the bigger population is vast and there's bound to be some individuals with higher tolerance of whatever the change is, be it increased temperatures, environmental toxins, or loss of food supplies. If one individual has the gene that boosts survival, it can propagate through the species very rapidly due to short lifespans.
Think of the human species as the biological equivalent as a comet hitting the earth and you've got it about right.
Evolution is neither good nor bad, it is a description of what happens. It's kind of like calling gravity or relativity good or bad. There also is no such thing as "de-evolution." Evolution is the change of allele frequencies within a population over time due to differential reproductive success. If this results in a "simpler" form of organism or the extinction of the species all together, it's still evolution. Of the five great extinctions to hit the earth, none of them caused any "de-evolution," they just killed off a good portion of extant species and left a lot a niches open for the survivors to exploit. We might be at the begining of the next great extinction event (though I doubt it'll get to that point, as I think we'll clean up our act before it happens).