A fished dolphin presenting a training of lower limbs A dolphin somewhat surprising has been just captured by Japanese fishermen off the West coast of Japan. Its characteristic: to present a supernumerary pair of fins, resurgence of the legs back of its terrestrial ancestors. The study of the fossils shows that the current dolphins have as an ancestor a terrestrial mammal with four legs, commun run with the whales and the hippopotamuses, and which lived 50 million years here. Evolution towards the dolphins which one currently knows started approximately 35 million years ago. The species then transferred and lost its legs little by little postpones, during that it adapted to the watery life. These members do not have however not yet completely disappeared: during its development embryonic, the foetus of the dolphins sees members postpones to be formed, small legs, which retract then and are not visible any more with the birth. The dolphin captured last on October 28 presents two pairs of fins against only one usually. The additional pair, smaller than the “natural” pair, was formed with the back of the animal, near to its tail, and a symmetrical way. These supernumerary members could be the result of a genetic change, causing the resurgence of the additional members of its ancestors. Radiographies and studies on the ADN of the animal will be undertaken in order to determine the causes of this change. Source: Geographic national Illustration: Taiji Whale Museum

Neurons in spindle, named thus because of the shape of their cellular body, would be implied in the feeling of love as well as other emotions. This discovery in the whales would start again the debate at the same time on question of their intelligence but also about the ethical question of their hunting by the man. Indeed, the neurons in spindle are located in zones of the brain responsible for our social organization, of our empathy (capacity to guess or feel the emotion of the others), word and other reactions fast and instinctive. It would seem that these neurons exist in cerebral areas counterparts in the humpback whale, the orcs, the fin-back whale and the cachalot. Moreover, the first estimates suggest that they possèderaient three times of them more than the human ones, by taking of account the difference in size. According to Patrick Hof, medical school of the Sinai Mount in New York (the USA), Co-discoverer of the neurons in spindle in the whales with Estel van der Gucht of the Consortium of Primatologie Evolutionary in New York (the USA): “It is extremely clear for me that they are very intelligent animals. We must be careful relating to our anthropomorphic interpretations on the intelligence of the whales. Their potential for high level cerebral functions is clearly shown at the behavioral level and is now confirmed by the existence of a neuronal type which was, thought one, present only in the man and his nexts of kin ". “They [whales] communicate with an enormous repertory of sounds, it recognize their own sounds and make the new ones. They also form coalitions to carry out strategies of hunting, learn them to the youngest individuals and have a social network evolved/moved similar to that of human and large monkeys”. As at the man, the neurons in spindle were detected in the cortex cingulaire former and the cortex fronto-islander, two areas essential for the “visceral” reactions emotional. Such reactions are based on fast emotional judgements, such as knowing or not if another animal suffers or the general feeling if an event is pleasant or unpleasant. Moreover, unlike the human ones, the researchers found these neurons in the whales in the fronto-polar cortex, in front of the brain, and also disseminated in a scattered way elsewhere. Hof states not to know the reason of the presence of the neurons in spindle in the areas other than those established in the man and the large monkeys. The neurons in spindle were on the other hand not discovered at the dolphins. Hof specifies that it would be interesting to compare the intelligence of the humpback whales with that of the dolphins. It is probable that the brain of the dolphins uses a strategy completely different from that of the cells in spindle to reach results undoubtedly comparable. Source: The Anatomical Record