Silkweaver says: The human genome has only about 25 percent more genes than the amphioxus genome, according to Holland. During evolution, humans have duplicated genes for different functions. Such duplication has given humans and other vertebrates a much larger "toolkit" for making various structures that are absent in amphioxus, including cells for pigment and collagen type II-based cartilage, for example. "vertebrates have employed old genes for new functions" This is an interesting strategy of evolutionary processes, that lend credibility to both the vast variability of life forms, and the speed of evolution of certain species. So many of the 'missing links' that we are searching for in fossils, still survive in creatures that exist today. We will learn by what we find, and what we learn, will give us leads as to where to look further. The cyclic nature of the world environment means conditions both change, and repeat themselves. Why throw something away that may come in useful in the future, when leaving will cause absolutely no trouble? Waiting to be triggered when conditions make them necessary again. Reminds me a bit of how people can put something like money away for safekeeping, then forget it entirely, only to find it when moving house - when money would be needed far more than when it was put away. Putting... |
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