Living the Good Life, For the Past 20 Million Years

A new study out by Collar, et. al. suggests that largemouth bass have changed little over the past 20 million years since optimal feeding development occurred. It seems natural selection stopped after bass developed their large mouths and well balanced shape which allowed for higher order food chain dominance. You can read more at the two links below. The first is a good one-page article in layman's terms from EurekAlert. The latter the actual research paper out of UCDavis which contains a cool 'family tree' of centrarchids, along with the standard 'science talk'.

• Freshwater fish at the top of the food chain evolve more slowly
• PISCIVORY LIMITS DIVERSIFICATION OF FEEDING MORPHOLOGY IN CENTRARCHID FISHES

Comments

[Paul Roberts]

Very neat stuff. Can't wait to read it.

[richard ziert]

We are all connected at the hip.

Evolution is like a vessel that can expand and contract. Once reaching the top or near the top of the food chain, there is no place to go but down. That usually happens with the introduction of competing species, and over harvest. That “introduction” can be then, additional evolution by other species both in and out of the water. Once tasting, or living off of a fish diet, a meat, or high protein, and vitamin/mineral diet, a diet that offers the most an ecosystem has to offer, the species seemingly stops evolving and begins its own extinction. But even extinction is a part of evolution. For example, man is a distant relative of the shark; both top predators in their designated environments. Bass are in many cases the top rung of the evolutionary ladder only so long as man doesn’t interfere. Evolution is change in growth and protection, and in elimination. High protein diets enlarge parts of the brain that enhance evolution. Humans were largely meat eaters early in their evolutionary path. Still, bass, sharks, and humans will eat the easiest meal they can find; turning only to "meat" out of necessity, immediate opportunity, or in its abundance and where energy expenditures do not on average outweigh the benefit.