10 hours ago Helen Briggs BBC environment correspondent•@hbriggs Sloths have a reputation for being sluggish and slow, spending most of their lives dozing in trees, but a new study suggests this is one of the enduring secrets of their success.
Scientists have examined the evolutionary history of the animals, including extinct forms known only from the fossil records.
The researchers say it is a reminder of the need to conserve Earth’s remaining sloths, which represent only the tip of the iceberg of 30 million years of evolutionary history.
But around 15,000 years ago, sloths started to die out.
In the new study, researchers analysed the body size of sloths across their evolutionary family tree and combined this with genetic data.
Ten hours ago.
Briggs, Helen.
Environment correspondent for the BBC •@hbriggs.
According to a recent study, sloths’ reputation for being slow and lethargic—they spend the majority of their lives sleeping in trees—may actually be one of the long-standing factors contributing to their success.
The evolutionary history of the animals, including extinct species only known from fossil records, has been studied by scientists.
It is said that the first human hunters found it easy to prey on the enormous sloths that roamed the land.
Little sloths in the trees, on the other hand, were able to survive.
The remaining sloths on Earth are merely the tip of the iceberg of 30 million years of evolutionary history, and the researchers say this serves as a reminder of the need to conserve them.
Dr. Alberto Boscaini, who led the study, of the University of Buenos Aires, stated, “Some sloths are here with us today, some of them are at risk of extinction, and one take home message is that we need to act now to avoid a total extinction of the group.”.
These days, sloths are tiny, tree-dwelling mammals that are only found in South and Central American rainforests. They are renowned for their adorable faces and laid-back manner.
However, hundreds of distinct sloths of all sizes and shapes that were adapted to survive in a variety of environments once roamed the Americas. Sloths, some of which grew as large as elephants and taller than men, lived on the ground, in underground caverns and tunnels, and even in water.
However, sloths began to become extinct about 15,000 years ago. There is disagreement among scientists regarding the causes of their death, with some blaming environmental factors like climate change, human hunting, or a combination of the two.
The new study combined genetic data with an analysis of sloth body size throughout their evolutionary family tree.
Without any lasting consequences, they discovered that sloths frequently changed the size of their bodies to adapt to climatic shifts. When humans began to spread throughout the Americas and hunt large mammals for food, their “abrupt and precipitous decline” occurred.
According to the scientists, larger ground-dwelling sloths would have been a relatively easy target and were the ones that began to disappear.
Conversely, smaller sloths that lived in trees were mainly overlooked and are still alive today.
Because of their extremely low metabolic rate, sloths are incredibly slow. According to Dr. Boscaini, this is their survival tactic.
“Unfortunately, we lost something that cannot be replaced, but we can preserve the ones that are still alive,” said Dr. Daniel Casali, a co-researcher from the University of São Paulo in Brazil. “,”.
Science is the journal where the research was published.
