Photo of an old German owl, left, and Racing Homer, right. Two domestic pigeons are the ancestors of more than 100 pigeons, and the study looked at why the crane sizes of domestic pigeons vary widely. (Sydney Stringham via University of Utah)
Salt Lake City – There are many animals of interest during Charles Darwin’s 19th century mythology.
It may be commonly associated with turtles and sparrows, but it was mostly inhabited by domestic pigeons. Because he noted that domestic pigeons were artificially selected, the breed helped shape his theory of natural selection. Michael Villak wrote an article for “The Incubator” at Rockefeller University in 2013.
But one feature of pigeons he wondered: why are there more than 300 different pigeon species with cranes of different shapes and sizes, including very short cranes, which are difficult for parents to feed their young?
For more than a century, researchers at the University of Utah have claimed that they now have the answer to what they call “Darwin’s short-sighted mystery.” They claim that pigeons’ short cranes are the result of a genetic mutation that causes the same Rubino syndrome in humans. Their findings were published in the journal Tuesday. “Current Biology. “
To achieve their findings, the team of researchers bred two pigeons with different cranes. Michael Shapiro, James E. in Biology at the University of Utah. Dalmage leader and senior author of the study explained that domestic pigeon breeders chose cranes based on aesthetics rather than anything that would benefit the species in nature. For this reason, researchers knew they could find the genes responsible for different crane sizes.
“One of Darwin’s big arguments is that natural and artificial selection are differences in the same process,” Shapiro said in a statement Tuesday. “The size of the pigeons’ hooks helped figure out how this works.”
The group began breeding Homer aircraft with a medium-sized bill like an old rock pigeon with an old German owl, a luxurious little crane pigeon breed despite the name. Its chick is characterized by medium-length cranes; When these birds mated with each other, their offspring appeared with different crane sizes and shapes.
Elena Boer – a clinical diversity scientist at ARUP Labs, a former postgraduate researcher at the University of Utah and lead author of the study – later used microcomputed tomography to measure the beaks of more than 100 birds produced as offspring of the original pigeon pair. Found that not only do birds’ cranes differ, but they also differ in the slender shape of the bird.
“These analyzes showed that crane variation within the group was due to actual differences in beak length rather than skull or total body size,” he said in a statement.
But the paper’s greatest discovery is that there are short cranes as a result of changes in the ROR2 gene. It was discovered in two steps.
They initially used a process called quantitative loci mapping, which helped identify variations in DNA sequence and the ability to search for mutations in offspring chromosomes. The results confirmed what the researchers expected based on previous traditional genetic tests, Shapiro said. He said grandchildren with small bills were found to have “the same piece of chromosome” as a small bill grandfather.
They then analyzed all the genetic sequences of different pigeon strains. This study showed that the gene containing the ROR2 gene had the same DNA sequence for all small bill birds. Boer said it was “very exciting” to find the same results in two different ways, because it confirms that the ROR2 gene is an important factor in crane levels.
He said the ROR2 gene mutations also lead to rubin syndrome in humans.
“Some notable features of Rubino syndrome are facial features, a broad and prominent forehead and a narrow and wide nose and mouth, reminiscent of the short crane pinotype in pigeons,” he explained. “This makes sense from a developmental perspective because we know that the ROR2 signal pathway plays an important role in cranial spine development.”
One of Darwin’s many dilemmas related to animal mutations has now been solved.
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