Parasite DNA from & # 39; the first gastric infection in the world & # 39; is found in 17,000-year-old excrements from a cougar that lived in the last ice age
- The fossilized stool was radiocarbon dated to 17,000 years ago by scientists
- Contains microscopic eggs from intestinal parasite known as a coprolite
- May spread from animals to humans and cause rash, headache and diarrhea
- DNA in the parasite is the oldest of its kind ever discovered by scientists
The earliest evidence ever for parasitic DNA is found in the fossilized faeces of an old cougar.
Feces from 17,000 years ago contain eggs from a parasite, a coprolite, a intestinal parasite that nowadays affects cats, dogs and foxes.
Microscopic eggs were identified in the feces of the predator that once roamed Argentina.
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The oldest DNA of parasites ever (right) is found in the old, dried-out stool of a puma (left)
The eggs belonged to Toxascaris leonina, a type of roundworm that is nowadays found in the digestive system of cats, dogs and foxes.
It can be picked up by people from contaminated soil. Symptoms include rash, headache, sore throat and diarrhea.
Spectacular mammals prowled the pampas, including the saber-toothed cat smilodon with seven centimeters of teeth, giant sloths and horrible wolves, the largest dog ever.
There were also herbivores such as stilt legs and South American camelids – such as llamasa and alpacas – that the cougars might have been hunted for.
Dr. Romina Petrigh, of the National University of Mar del Plata in Buenos Aires, said: & although we have found evidence of parasites in coprolites, those remains were much more recent and date only a few thousand years ago.
& # 39; The latest finding shows that these roundworms infected South America's fauna before the arrival of the first humans in the area, about 11,000 years ago. & # 39;
Archaeologists believe that the number of cases of parasitic disease in humans increased as hunter-gatherer populations became farmers.
This would have put them in regular contact with accumulated waste and droppings, making the infections more likely.
The coprolite was excavated in a cave in the mountainous province of Catamarca on the southern Puna plateau in northern Argentina.
Remains of the now extinct megafauna were previously excavated on the same site.
Analysis of the mitochondrial DNA in the dried faeces confirmed that it was from a species of a Puma concolor – commonly known as a cougar.
At the time – geologically known as the end of the Pleistocene – the area around the shelter called Penas de las Trampas would have been wetter than today.
This made it a suitable habitat for both the huge beasts and the smaller wildlife they were hunting.
Dr. team Petrigh analyzed the old mitochondrial DNA in the dried faeces analysis to confirm that it was from a species of a Puma concolor – commonly known as a cougar.
The extremely dry, cold and salty conditions that occurred after the ice age helped to reduce DNA degradation, which explains the excellent retention.
Dr. Petrigh said: & # 39; I was very happy when I discovered how old this DNA was.
& # 39; It is difficult to restore DNA from such a good age, because it usually gets damaged over time.
& # 39; Our working conditions had to be checked extremely to prevent contamination with modern DNA, so we used special disinfected reagents and disposable supplies.
& # 39; Several experiments were conducted to authenticate the DNA sequences obtained and the efforts of the team of researchers who participated were essential. & # 39;
The research is published in the journal parasitology.
Microscopic eggs were identified in the feces of the predator that once roamed Argentina
WHAT DO WE KNOW ABOUT OLD MEGAFAUNA?
The earth was once inhabited by a variety of gigantic forms of animals that would be recognizable to us today in the smaller forms that their ancestors had assumed.
They were very large, usually more than 88 pounds (40 kg) in weight and generally at least 30 percent larger than all their living relatives.
There are several theories to explain this relatively sudden extinction. The most important explanation was that this was due to environmental and ecological factors.
It was almost complete by the end of the last ice age. It is believed that mega fauna initially arose in response to ice conditions and died out with the onset of warmer climates.
In temperate Eurasia and North America, the extinction of mega fauna was simultaneously terminated with the replacement of the huge periglacial tundra by a vast forest area.
Glacial species, such as mammoths and woolly rhinos, were replaced by animals that were better adapted to forests, such as moose, deer and pigs.
Reindeer and Caribou retreated north, while horses moved south to the Central Asian steppe.
This all happened about 10,000 years ago, despite the fact that people colonized North America less than 15,000 years ago and non-tropical Eurasia nearly a million years ago.
There are no indications worldwide that indigenous peoples systematically hunt megafauna and do not kill them too much.
The largest regularly hunted animal was bison in North America and Eurasia, but it survived for approximately 10,000 years until the beginning of the 20th century.
For social, spiritual and economic reasons, First Nations people have harvested game in a sustainable way.
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