These New Orleans lizards are full of lead
Lead is highly regulated today, but this was not always the case for toxic heavy metal. In fact, the industrial ingredient was both omnipresent that experts estimate that around 90% of Americans born between 1951 and 1980 have raised problematic levels of the element of their blood circulation during childhood. Although lead pollution remains a major public health and an environmental risk in a large part of the world, at least one species is amazing researchers with its unexpected resilience.
Cuban brown lizards (Anolis Sagrei) New Orleans, in Louisiana, contain the highest levels of blood never seen in a vertebrate, according to a study published in the journal Environmental researchThe percentage is so high that a similar concentration would probably kill most other animals. However, the Anoles are not only imperturbable – they continue their invasive spread in the region.
“These lizards do not survive, they thrive with [a] The main burden that would be catastrophic for most other animals, “said the co-author of the study and an evolutionary biologist at the University of Tulane, Alex Gunderson, in a press release.
Unlike the city’s native green Anole (Anolis Carolinensis), experts believe that Brown Anole arrived by the Caribbean as recently as the 1990s. Their number has particularly exploded in the past two decades, with a population that now exceeds its native reptile parent. Unlike these relatively new arrivals, however, New Orleans was established as French colonial colonization in 1718. The city of today and its value of more than three centuries of civic infrastructure, technological advances and industrialized life provide an excellent backdrop to study long-term environmental effects to say
“New Orleans is an old town, which means that it has a long history with things like lead paint and lead essence, and that leads from these sources have made their way in dirt,” explains Gunderson Popular science.
He says that the study of lead levels requires studying the soil itself and that lizards are a large animal to use as a reference point. “The lizards live near the ground, they therefore breathe dust with lead and eat insects that have led on and in them,” explains Gunderson.
In their article, Gunderson and Project Lead Annelise Blanchette also wrote that the Bruns Anoles are particularly useful because they are already used as a model system in urban, physiological and evolutionary ecology “.
“My goal was also to understand how life in cities has an impact on fauna, and these lizards are well suited to cities, so I was curious to know if we saw anthropogenic effects,” says Blanchette Popular science. The results of his curiosity quickly left her “absolutely shocked”.
After collecting wild brown anoles and analyzing organic samples, Blanchette and her colleagues discovered that lizards presented the average and individual concentrations of the highest blood drift of all known vertebrate. In addition, they have shown little or no disabilities to the capacities often affected by lead poisoning, such as sprint speed, endurance and balance. Other experiences have shown that the brown anoles required lead consumption about 10 times higher than their already intense levels to train any notable deterioration. The brain’s tissues and the Anoles liver also revealed “minor effects” of lead exposure.
“I saw that the levels were high, but he didn’t really clicked with me until we confirmed the first cycle of data,” said Blanchette. “Once I realized that blood lead levels, other free wild animals tend to face much lower, I was amazed by the Anoles. I knew that we had sort of stumbled on something special. ”
We do not know exactly how or why the brown Anoles of New Orleans treat lead as if it was not serious, although the researchers noted that the lizards presented several modified genes linked to the regulation of metallic ions and the transport of oxygen. That said, the researchers warned against thought that all human genetics bio-engineering to tolerate larger quantities of lead is a viable path to follow. Instead, they say that their discovery emphasizes the importance of exploring more the large -scale ecological effects of lead.
“We have to reassess what we know about toxicity thresholds in vertebrates,” said Gunderson. “If we can understand what protected them, we could discover strategies that could help alleviate the poisoning of heavy metals in people and other species.”
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