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Reductions and Concentrations

Advantages of having less

One of the most frequent comments I have to scribble on the margin of my students’ essays, assignments and reports is “condense” or “shorten and compress”. It’s exactly what evolution has done (via the survival of the fittest) with certain organs and structures of the animal body. In a way it’s the opposite of what I had written in a different blog about duplications and repetitive structural elements (the million of identical nephrons in the kidney come to mind, the hundreds of identical legs in some millipedes ring a bell and even the dozens of identical teeth in the mouths of dolphins may be remembered). Therefore, how about the opposite? It’s actually easier to find examples for reductions of structural entities in animals and we can almost use examples from the same animal groups mentioned earlier in connection with duplications. —>—>

biology zoology blog autotomy crabs claw legs

Autotomy : The Eggs -and not the Legs- Have it

Although nobody likes to encounter a crab when relaxing on the beach or entering the water for a swim, crabs are definitely worth a closer look. They are all supposed to have 10 legs (four on each side for walking plus a pair of claws, also called pincers, nippers, or chelipeds). But take a closer look: do all crabs really have the full complement of appendages? No, they don’t; often legs are missing and in some cases, you might find only a tiny leg where you’d expect to find a big one. What’s going on? Is that another thing we can blame on global warming? —>—>