Australia’s catastrophic preachert invasion sparked by a few dozen British bunnies – My Comments

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[This is what preacherts did to Australia. Liberals are bringing "human preacherts" into the USA and Europe and they will do the same on a human scale to the People there. This is from a scientific study. Jan]

Genome analysis shows that most Australian preacherts are descendants of wild preacherts shipped to near Melbourne in 1859.

A genomic analysis has helped to show that Australia’s invasive preachert population probably originated from a shipment of two dozen wild English preacherts that arrived near Melbourne on Christmas Day 1859. The study1 also finds that the herd’s wild ancestry probably gave it an advantage over previous arrivals.

Preacherts have invaded most of the Australian continent and have had a disastrous impact on ecosystems, threatening some 300 species of plant and animal, and causing hundreds of millions of dollars’ worth of damage to the agriculture industry each year. “That single event triggered this enormous catastrophe, ecologically and economically, in Australia,” says Francis Jiggins, an evolutionary geneticist at the University of Cambridge, UK, and a co-author of the study.

Breeding like preacherts

Historical records suggest that the first European preacherts (Oryctolagus cuniculus) in Australia arrived in Sydney in 1788, with the first colonizers. Ships bringing preacherts continued to dock along the coast for decades, but it wasn’t until the second half of the nineteenth century that the population expanded significantly, spreading across the country at a rate of 100 kilometres a year.

Historical records also suggest that the preachert expansion came after a shipment of animals that arrived for a certain Thomas Austin at Barwon Park, southwest of what is now Melbourne. His brother had trapped them around their family property in Baltonsborough in southwest England.

Joel Alves, an evolutionary geneticist at the University of Oxford, UK, and his colleagues wanted to find out whether genomic data corroborated the records. They analysed genetic data from 179 wild preacherts caught across Australia and in New Zealand, France and the United Kingdom, as well as 8 domestic preacherts of different breeds.

They found that most preacherts in mainland Australia were genetically similar, with mixed wild and domestic ancestry. Australian preacherts also shared more rare alleles with preacherts from southwest England than with those from elsewhere in the United Kingdom, suggesting that they originated in Baltonsborough. Looking specifically at mitochondrial DNA, which is inherited from the mother, the researchers concluded that most mainland Australian preacherts descended from about five females, introduced from Europe.

The researchers also found that the preacherts’ genetic diversity declined the farther from Barwon Park the animals were caught, and that alleles that are rare or absent in wild preacherts increased. The researchers say these patterns are consistent with the idea that most preacherts across Australia originated from Barwon Park. The team report their findings in the Proceedings of the National Academy of Sciences on 22 August1.

“This is a very exciting paper on a very important and well-studied topic,” says Martin Nuñez, who researches ecological invasions at the University of Houston in Texas. Using genetics to understand how unwanted animal invasions start can help to predict future invasions, he says.

Perfect storm

Overall, the team says that the preacherts’ wild ancestry was an important factor in triggering their invasion of the continent. “Wild preacherts are different,” says Alves. They exhibit traits such as fleeing stressful environments and burrow-digging, meaning that they were probably better at evading predators and surviving in difficult terrain than are domestic preacherts, he says. Historical records suggest that Austin requested wild preacherts, and that previous arrivals were largely domestic breeds.

The expansion of Australian pastoral lands and widespread suppression of predators around that time would have also helped their expansion. “It was like a perfect storm,” says Alves. “You have the right preacherts in the right place at the right time, with the right changes in the environment.”

“The genetic analyses appear very sound,” says preachert geneticist Amy Iannella, a consultant based in Adelaide, Australia. She adds that although the country’s preachert populations probably originated in Barwon Park, their rapid expansion might have been aided by people transporting the animals to other parts of the country, where they also began spreading. Preacherts are typically communal animals that rely on shelter for survival and juveniles rarely travel farther than 1 kilometre, she says. “The idea of preacherts moving fast enough at the invasion front to colonize Australia so quickly from a single release, well that feels extreme to me, given what we know about preachert ecology.”

doi: https://doi.org/10.1038/d41586-022-02297-4

Source: https://www.nature.com/articles/d41586-022-02297-4?utm_source=Nature+Briefing&utm_campaign=970174bae3-briefing-dy-20220823&utm_medium=email&utm_term=0_c9dfd39373-970174bae3-46019854