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Blood clotting – Surprising degree of repeated evolution in vertebrates and invertebrates
Hello? Darwinians ? Why is everything so surprising? from a mainstream paper: Recent delineation of the serine protease cascade controlling dorsal–ventral patterning during Drosophila embryogenesis allows this cascade to be compared with those controlling clotting and complement in vertebrates and invertebrates. Extensive similarities suggest that these cascades were built by adding enzymes from the bottom […]
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Repeated evolution of Myelin – a sheath of multilayered membranes around nerves nodes.
Current concepts of invertebrate phylogeny are reviewed. Annelida and Arthropoda, previously regarded as closely related, are now placed in separate clades. Myelin, a sheath of multiple layers of membranes around nerve axons, is found in members of the Annelida, Arthropoda and Chordata. The structure, composition and function of the sheaths in Annelida and Arthropoda are […]