Home Education 150-year-old platypus specimens that have proven that some mammals lay eggs –...

150-year-old platypus specimens that have proven that some mammals lay eggs – ScienceDaily

Emissions from international trade in agricultural products are growing - ScienceDaily

Jars with tiny platypus and echidna specimens, collected in the late 1800s by scientist William Caldwell, have been found in stores at the Cambridge University Museum of Zoology.

At the time of collection, these samples were key to proving that some mammals lay eggs – a fact that changed the course of scientific thinking and supported the theory of evolution.

This unique collection was not cataloged in the museum, so staff until recently did not know about its existence. An exciting discovery was made when Jack Ashby, the museum’s assistant director, was conducting research for a new book on Australian mammals.

“It is one thing to read 19th century announcements that platypus and echinoderms do lay eggs. But to have here the physical specimens that connect us to this discovery almost 150 years ago is pretty amazing, ”Ashby said.

He added: “I knew from experience that there is no natural history collection on Earth that would actually have a complete catalog of everything in it, and I suspected that Caldwell’s specimens really should be here.” He was right: three months after Ashby asked collection manager Matthew Lowe to keep an eye out, a small sample box was found in the museum with a note certifying that they belonged to Caldwell. Ashby’s investigation has confirmed that this is indeed the case.

Until Europeans first encountered platypus and echidna in the 1790s, it was believed that all mammals give birth to live babies. The question of whether some mammals lay eggs has become one of the most important questions 19th century zoology, and was hotly debated in scientific circles. The recently discovered collection of small jars is a huge scientific effort to unravel this mystery.

“In the nineteenth century, many conservative scientists didn’t want to believe that egg-laying mammals could exist because it supports the theory of evolution – the idea that one group of animals can transform into another,” Ashby said. .

He added: “Lizards and frogs lay eggs, so the idea of ​​mammals laying eggs has been rejected by many people – I think they thought it humiliating to be related to animals they considered ‘lower life’.”

The recently opened collection includes carnivores, platypus and marsupials at various stages of life from fertilized egg to adolescence. Caldwell was the first to make complete collections of all stages of the life of these species – although not all specimens were found in the museum.

For 85 years, European naturalists have tried to find evidence that platypus and echinoderms lay eggs – including by asking Australian aborigines – but any results they sent home have been ignored or rejected.

William Caldwell was sent to Australia in 1883 – with considerable financial support from the University of Cambridge, the Royal Society and the British Government – to unravel a long-held mystery.

In an extensive search, Caldwell collected about 1,400 copies with the help of a large group of Australian Aborigines. In 1884, the team eventually found a caterpillar with an egg in its bag and a platypus with one egg in its nest, and another just had to be set aside.

It was the ultimate proof Caldwell was looking for, and the news spread around the world. The colonial scientific establishment apparently was ready to accept this result only now that it had been confirmed by “one of them.”

Ashby says that over the past two centuries, scientists have constantly humiliated Australian mammals, describing them as strange and inferior. He believes that this language continues to influence the way we describe them today, and undermines efforts to preserve them.

“Platypus and vulture are not strange primitive animals – as many historical stories portray them – they have evolved as much as anything else. They just never stopped laying eggs,” he said, adding: “I think they “absolutely amazing and definitely worth appreciating.”

Needle-covered echidna is the most common mammal in Australia. They cover the entire continent and have adapted to living in any climate – from snow-capped mountains to the driest deserts.

Platypus – one of the few mammals that can detect electricity, and one of the only mammals that produce venom. With a tail like a beaver, a flat beak and webbed legs like a duck, when the first specimens were brought to Europe, people thought it was a fake that had been sewn.

Both platypus and vulture have a unique combination of traits that 19th century scientists believe should exist separately in mammals, reptiles or birds. This has made them central to the debate over evolution.

Ashby’s new book, The platypus matters: An unusual story of Australian mammalspublished in the UK on 12 May 2022 by Harper Collins.

Source link

Previous articleThis new census tool can recruit students into the liberal arts
Next articleFlixTrain announces three new routes, including the first connection to Basel