![]() The eyes are small and have a third eyelid, or nictating membrane. The platypus uses it for probing the mud of the pools and rivers in search of the small insects and crustaceans on which it feeds. It appears horny when it is dry, but it is in fact covered with soft skin, and is very delicate and sensitive. Although the snout looks so much like a duck's bill, it is rather broader. ![]() The body is flattened in shape and, including the tail, grows to a total length of about 50 cm (20 in). In fact, the platypus as this extraordinary animal is called, is a very primitive mammal. An investigation of the live animal's showed that it laid eggs like a duck or a bird, but suckled its young like a mammal. It was just by chance that its beak look like a duck's bill. Experiments showed that its anatomy was halfway between that of a mammal and a reptile. However, there was no sign of artificial joins and examination of a specimen which had been preserved whole in alcohol made it clear that this was indeed a genuine animal. ![]() The Chinese were known to be very clever at constructing chimera in this way and selling them to sailors as curiosities. They said that the specimens must have been made up by joining together parts of a mammal and a bird. Some of the naturalists of the time simply refused to believe that such an animal could exist. The fur of this creature was like that of a mammal, but instead of a mouth it had a beak, which looked like a duck's bill. So why the considerable ability to sense odors? The scientists speculate that it may involve sexual communication or the use of water-soluble odorants in navigating and hunting underwater.Towards the end of the 18th century, European naturalists were mystified by the skins of some strange animals that had been brought from Australia. As a primarily aquatic animal, the platypus was already known to rely on electrosensory receptors in its bill to detect faint electric fields emitted by underwater prey. One surprise was finding genes responsible for sensitive odor receptors. The platypus lacks nipples the young nurse through the abdominal skin. Of particular interest, the researchers reported, the analysis identified families of genes that link the platypus to reptiles (like those for egg-laying, vision and venom production), as well as to mammals (antibacterial proteins and lactation). Some repeated elements in the genome, the scientists noted, hold hints as to the chronology of changes in the platypus. The platypus shares 82 percent of its genes with the human, mouse, dog, opossum and chicken. In their investigation of the platypus genetic blueprint, the scientists found that its genome contains about 18,500 genes, similar to other vertebrates and about two-thirds the size of the human genome. “What is unique about the platypus is that it has retained a large overlap between two very different classifications, while later mammals lost the features of reptiles,” Dr. Greg Wood/Agence France-Presse - Getty Images The single subject of the study was a female platypus named Glennie, a resident of Glenrock Station in New South Wales, Australia, whose DNA was collected and analyzed.Ī platypus baby, or puggle, being held before being transferred back to its burrow at Taronga Zoo in Sydney, Australia. Warren, a geneticist at Washington University School of Medicine in St. The research is described in Thursday’s issue of the journal Nature by a group of almost 100 scientists led by Wesley C. If it has a bill and webbed feet like a duck, lays eggs like a bird or a reptile but also produces milk and has a coat of fur like a mammal, what could the genetics of the duck-billed platypus possibly be like? Well, just as peculiar: an amalgam of genes reflecting significant branching and transitions in evolution.Īn international scientific team, which announced the first decoding of the platypus genome on Wednesday, said the findings provided “many clues to the function and evolution of all mammalian genomes,” including that of humans, and should “inspire rapid advances in other investigations of mammalian biology and evolution.”
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