06 APR 2015 by ideonexus

 The Need for an Internal Skeleton

The need for an internal skeleton stems largely from the nature of muscle tissue, which can exert force only by contracting and is therefore much more effective with a good lever system to work with. I belittle neither the intelligence nor the strength of the octopus; but in spite of Victor Hugo and most other writers of undersea adventure, the creature's boneless tentacles are not all that effective as handling organs. I don't mean that the octopus and his kin are helpless hunks of meat; but...
Folksonomies: physics biology speculation
Folksonomies: physics biology speculation
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30 MAY 2012 by RadioGuy

 Humans share 98.5% of our genes with chimpanzees

The genome is not a blueprint for constructing a body; it is a recipe for baking a body. As the hox story illustrates, DNA promoters express themselves in the fourth dimension; their timing is all. A chimp has a different head from a human being not because it has a different blueprint for the head, but because it grows the jaws for longer and the cranium for less long than a human being. The difference is all timing. The startling new truth that has emerged from the human genome - that...
Folksonomies: genetics
Folksonomies: genetics
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Even the difference between human and mouse blueprints are minor. Our variation comes from the schedules that manage the expression of genes, and these are controlled by the chemicals and enzymes in our environments.