 “There are about ten million species of animals, and they are fantastically varied. One would no more expect the worm, the flea, the eagle and the giant squid all be generated by the same developmental mechanisms, than one would suppose that the same methods were used to make a shoe and an airplane. Some similar abstract principles might be involved, perhaps, but surely not the same specific molecules?
One of the most astonishing revelations of the past ten or twenty years has been that our initial suspicions are wrong. In fact, much of the basic machinery of development is essentially the same, not just in all vertebrates but in all the major phyla of invertebrates too. Recognizably similar, evolutionarily related molecules define our specialized cell types, mark the differences between body regions, and help create the body’s pattern. Homologous proteins are often functionally interchangeable between very different species. A mouse protein produced artificially in a fly can often perform the same function as the fly’s own version of that protein, and vice versa, successfully controlling the development of an eye, for example, or the architecture of the brain.”
“Molecular Biology of the Cell”
Bruce Alberts…[et al.], 4th ed. |