It seems that a fossilized fish found about four years ago in the Arctic had wrists, forearms, elbows and shoulders that may have been the precursors for the equivalent arm parts that we humans enjoy today. I enjoy my arms, don’t you? Anyway, it seems that more and more of biology is discovering the great number of genetic similarities that living beings on this planet share, as mentioned in my last post ‘The Tree of Life Gets a Pruning’. One suggestion from the work concerning the Tiktaalik performed by Neil Shubin, professor of anatomy at Chicago University, is that the fin in fish is a refinement of the original, or older hand structure. Indeed, Shubin found that the genes exist in modern fish for this arm development, but are turned off. Clearly, very small changes in genes can manifest as very large differences in outward appearance in living beings. For instance, research has shown that some genes involved in the development of the human eye and vision, are also involved in jellyfish metabolism. How about that? Shubin has written what sounds to be an interesting book on the subject, titled “Your Inner Fish: A Journey into the 3.5 billion-year History of the Human Body”. You might want to use your wrists for a little book-reading enlightenment.

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