Pittsburgh

Why no tusks? Poaching tips scales of elephant evolution – Pittsburgh, Pennsylvania

Pittsburgh, Pennsylvania 2021-10-21 21:19:00 –

Large amounts of fangs are usually beneficial to elephants, allowing them to dig water, bark for food, and joust with other elephants. But during the episode of intense ivory poaching, those large incisors are responsible. Researchers have now identified how years of civil war and poaching in Mozambique have increased the proportion of elephants that never develop tusks. During the conflict between 1977 and 1992, fighters on both sides slaughtered elephants in search of ivory to fund war effort. About 90% of elephants have been killed in this area, which is now Golongosa National Park. Survivors could share important traits: half of the women naturally had no tusks and simply never developed tusks, but before the war they lacked tusks for five minutes. It was less than 1. Like the color of the human eye, whether an elephant inherits its fangs depends on genes. Their parents. Fangless conditions were once rare in African elephants, but have become more common as rare eye colors become more widespread. After the war, those fangless surviving females transmitted their genes with expected and surprising results. About half of their daughters had no fangs. To make matters worse, two-thirds of their descendants were women. Shane Campbell Staton, an evolutionary biologist based at Princeton University, said long-standing anxiety “changed the evolutionary trajectory of the population.” He worked with his colleagues to try to understand how the pressure of ivory trade changed the scale of natural selection. Their findings were published in the journal Science on Thursday. Researchers in Mozambique, including biologists Dominique Goncalves and Joyce Poole, have observed about 800 elephants in national parks over the years and created a catalog of mothers and offspring. Poole, science director and co-founder of the nonprofit Elephant Voices, said: Poole had previously seen other cases of elephant populations in Uganda, Tanzania, Kenya, etc., with disproportionately large tusksless females after intense poaching. “I’ve been confused as to why it’s a fangless woman for so long,” said Poole, co-author of the study. At Golongosa, the team collected blood samples from 7 tusked female elephants and 11 tusked female elephants and analyzed their DNA differences. Elephant survey data gave them an idea of ​​where to look: the fangless elephants were female, so they focused on the X chromosome. (Women have two X chromosomes, and men have one X chromosome and one Y chromosome.) I also suspected that the related genes were predominant. Short-circuit their development. “If a mother takes over, I think her son is more likely to miscarriage and die early in development,” said Brian Arnold, a co-author and evolutionary biologist at Princeton University. Their genetic analysis revealed two important parts of elephant DNA. They believe they play a role in communicating fangless traits. The same gene is associated with tooth development in other mammals. “They produced evidence of a smoking gun with genetic alterations,” said Chris Darimont, a conservation scientist at the University of Victoria, Canada, who was not involved in the study. This work “helps scientists and the general public understand how our society can make a significant impact on the evolution of other life forms.” Most people think that evolution is slow, but humans can hit accelerators. “When we think of natural selection, we think it’s been happening for hundreds or even thousands of years,” said Samuel Wasser, a conservation biologist at the University of Washington who wasn’t involved in the study. Said. “The fact that this dramatic fangless choice has been made for over 15 years is one of the most amazing discoveries.” Now scientists are saying more fangs for this species and its savanna environment. I’m studying what an elephant without a sword means. Preliminary analysis of fecal samples suggests that Golongos elephants are changing their diet without long incisors to remove the bark from the tree. Robert Pringle, co-author and biologist at Princeton University, said: “These changes will continue for at least multiple generations of elephants.”

Large amounts of fangs are usually beneficial to elephants, allowing them to dig water, bark for food, and joust with other elephants. But during the episode of intense ivory poaching, those large incisors are responsible.

Researchers have now identified how years of civil war and poaching in Mozambique have increased the proportion of elephants that never develop tusks.

During the conflict between 1977 and 1992, fighters on both sides slaughtered elephants in search of ivory to fund war effort. About 90% of elephants have been killed in this area, which is now Golongosa National Park.

Survivors could share important characteristics. Half of the women naturally had no tusks and simply never developed tusks, but before the war less than one-fifth lacked tusks.

Like the color of the human eye, genes are responsible for whether an elephant inherits its fangs from its parents. Fangless conditions were once rare in African elephants, but have become more common as rare eye colors become more widespread.

After the war, those fangless surviving females transmitted their genes with expected and surprising results. About half of their daughters had no fangs. To make matters worse, two-thirds of their descendants were women.

Shane Campbell Staton, an evolutionary biologist based at Princeton University, said long-standing anxiety “changed the evolutionary trajectory of the population.”

He worked with his colleagues to try to understand how the pressure of ivory trade changed the scale of natural selection. Their findings were published in the journal Science on Thursday.

Researchers in Mozambique, including biologists Dominique Goncalves and Joyce Poole, have observed about 800 elephants in national parks over the years and created a catalog of mothers and offspring.

Poole, science director and co-founder of the nonprofit Elephant Voices, said:

Poole had previously seen other cases of elephant populations in Uganda, Tanzania, Kenya, etc., with disproportionately large tusksless females after intense poaching. “I’ve been confused as to why it’s a fangless woman for so long,” said Poole, co-author of the study.

At Golongosa, the team collected blood samples from 7 tusked female elephants and 11 tusked female elephants and analyzed their DNA differences.

Elephant survey data gave them an idea of ​​where to look: the fangless elephants were female, so they focused on the X chromosome. (Women have two X chromosomes, and men have one X chromosome and one Y chromosome.)

They also suspected that the associated gene was dominant-that is, only one modified gene was needed for a woman to become fangless-and when passed to a male embryo, It may short-circuit their development.

“If a mother takes over, I think her son is more likely to miscarriage and die early in development,” said Brian Arnold, a co-author and evolutionary biologist at Princeton University.

Their genetic analysis revealed two important parts of elephant DNA. They believe they play a role in communicating fangless traits. The same gene is associated with tooth development in other mammals.

“They produced evidence of a smoking gun with genetic alterations,” said Chris Darimont, a conservation scientist at the University of Victoria, Canada, who was not involved in the study. This work “helps scientists and the general public understand how our society can make a significant impact on the evolution of other life forms.”

Most people think that evolution is slow, but humans can hit accelerators.

“When we think of natural selection, we think it’s been happening for hundreds or even thousands of years,” said Samuel Wasser, a conservation biologist at the University of Washington who wasn’t involved in the study. Said. “The fact that this fangless and dramatic choice has been made for over 15 years is one of the most amazing discoveries.”

Scientists are now studying what more fangless elephants mean for this species and its savanna environment. Preliminary analysis of fecal samples suggests that Golongos elephants are changing their diet without long incisors to remove the bark from the tree.

Robert Pringle, co-author and biologist at Princeton University, said: “These changes will continue for at least multiple generations of elephants.”

Why no tusks? Poaching tips scales of elephant evolution Source link Why no tusks? Poaching tips scales of elephant evolution

Back to top button