subscribe to this pageDRAGONS and virgin births are the stuff of myth and religion. Except, that is, in Kansas, where they have recently come together in a way that should alter the way many of us look at nature and demonstrate the risks in our habit of using it to help us make ethical decisions.
Scientists have discovered fossils of a 375-million-year-old fish, a large scaly creature not seen before, that they say is a long-sought missing link in the evolution of some fishes from water to a life walking on four limbs on land.
Working in rocks more than 375 million years old far above the Arctic Circle, paleontologists have discovered a remarkable new fossil species that represents the most compelling evidence yet of an intermediate stage between fish and early limbed animals.
Four years ago, while digging in the Canadian Arctic, paleontologist Neil Shubin discovered the 375 million-year-old fossil of a fish that appeared to have both neck and hands. It was seemingly clear evidence of the transition from life in water to life on land. Scientists heralded the find as their best answer yet to the creationist argument that an absence of such "missing links" is evolutionary theory's most obvious flaw.
Wrists, ankles and digits distinguish tetrapod limbs from fins, but direct evidence on the origin of these features has been unavailable. Here we describe the pectoral appendage of a member of the sister group of tetrapods, Tiktaalik roseae, which is morphologically and functionally transitional between a fin and a limb. The expanded array of distal endochondral bones and synovial joints in the fin of Tiktaalik is similar to the distal limb pattern of basal tetrapods. The fin of Tiktaalik was capable of a range of postures, including a limb-like substrate-supported stance in which the shoulder and elbow were flexed and the distal skeleton extended. The origin of limbs probably involved the elaboration and proliferation of features already present in the fins of fish such as Tiktaalik.