Climate change, not humans, has fueled the decline of prehistoric elephants, mammoths and mastodons

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July 1 (UPI) – Sudden and dramatic environmental changes triggered by climate change led to the decline of prehistoric elephants, mammoths and mastodons – and humans probably played only a minor role in their demise, according to a new study.

For decades, hunters and gatherers have been the prime suspects in the case of the planet’s vanished megafauna.

After all, their descendants, modern humans, have severely damaged the earth’s ecosystems and wiped out dozens of plant and animal species.

But the latest findings – published on Thursday in the diary Natural ecology and evolution – suggest that the appearance of small groups of spear-wielding people cannot explain the rise and fall of elephants, prehistoric and others.

Yet there were many more large animals in the past than there are today.

Thousands of years ago, a wide variety of large proboscis – the group of large herbivores that includes mammoths and mastodons – roamed the planet.

Today there are only three species left, all of which are endangered and banished to the tropics of Asia and Africa.

To better understand the evolutionary history of elephants and their relatives, an international team of paleontologists conducted a comprehensive review of the adaptive properties developed by 185 different trunk species.

The review included tooth and skull features, chewing methods, tusk size, body mass, and locomotion, among other things.

This analysis enabled scientists to better appreciate the wide variety of shapes and ecologies that proboscis assumed in the millions of years before the arrival of early humans.

Using sophisticated statistical techniques, the researchers modeled the emergence of these various adaptations over time and space.

“We discovered that the ecological diversity of the proboscis increased dramatically when they spread from Africa to Eurasia about 20 million years ago and to North America about 16 million years ago when land links formed between these continents,” the co-author said Study, Steven Zhang, opposite UPI. in an email.

“After these events, diversity increased in Africa too,” said Zhang, a research fellow at the University of Bristol in England.

Before this exodus, the prehistoric trunk animals of ancient Africa developed rather slowly.

In fact, the trunk animals of the Oligocene, the epoch that began about 33 million years ago, didn’t look much like elephants, and most of the morphological experiments were evolutionary dead ends.

After these archaic North African lineages fled to Europe and Asia, the evolution of the proboscis accelerated by a factor of 25 as prehistoric elephants quickly adapted to capitalizing on a plethora of ecological opportunities.

Unfortunately, the boom times don’t last forever. The analysis showed not only the point in time of proboscis diversification, but also periodic declines in proboscid speciation.

“For about 6 million years, and especially for 3 million years, the ecomorphological diversity of proboscis began to gradually decline worldwide after the events of climatic cooling and hardening,” co-author Juha Saarinen, postdoctoral fellow at Helsinki University in Finland, informed UPI in an email with.

According to the authors of the new study, people cannot explain these periodic declines.

“In Africa, for example, we see the great extinction pulse of the proboscis around 2.4 million years ago, when members of the evolving hominin line were still very bipedal chimpanzees in terms of their functional ecology,” said Zhang.

“The recent extinction of proboscis that we have discovered on different continents has not been accompanied by improved hunting skills in archaic hominins or the settlement of Homo sapiens on the various land masses,” said Zhang.

The latest evidence doesn’t rule out any human influence on proboscis extinction, researchers said, but it does suggest that there was an increased risk of proboscis extinction in Africa, Eurasia and America before the arrival of big game hunters.



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