Back in the day, life on Earth seemed more impressive.. A little over 100,000 years ago, there were sloths the length of the giraffe we know today, and feral bears whose shoulders were several meters above the ground..
Before that, there was a type of elephant called(Palaeoloxodon) He can put his chin on the head of a modern African elephant. There was also a rhinoceros without horns called(Paraceratherium)which weighed at least ten times more than a living rhinoceros today.
After the extinction of most of the dinosaurs at the end of the Cretaceous period, 66 million years ago, mammals became the largest creatures on Earth, and they became really big..
But over time, all of these creatures have disappeared in such a fast and mysterious way that scientists are still unable to fully explain what happened..
Between scientific beliefs that an asteroid struck the Earth was the reason for the annihilation of these huge monsters, similar to the one that is believed to have wiped out the dinosaurs, and between widespread climate change, and epidemics of new diseases, it is believed that many factors led to the annihilation of the huge animals of our planet.
The role of man in the extinction of megafauna
In a study published in 2018 in the journal Science Provides evidence that the principal motives were mainly humans and hominids.
“We looked at the entire fossil record for 65 million years and found that for most of evolutionary history, greater body mass did not make the animal more vulnerable to extinction,” explains Phylissa Smith, a paleobiologist at the University of New Mexico.“.
However, a new species of predator was found on the scene, Homo erectus, scientifically known as (Homo Erectus).
About 1.8 million years ago, humans, who had been dependent on plants for much of their lives, became increasingly dependent on meat as a food source..
With the spread of animal hunters who use deadly tools, the extinction of large mammals from animals followed.
It is also possible that humans have actively targeted the most powerful and largest creatures on Earth for other reasons, including fear, or competition for prey, for example..
Likewise in the modern era, human conflict is often related to large animals because of their aggression on our livestock and important sources of our food, as is the case with wolves and lions, or because of their destruction or consumption of our crops, as is the case with elephants and others in some countries.
Large animals and rapid reproduction difficulty
William Ripple, a researcher at Oregon State University in the United States, said that something about large animals makes them more likely to collapse numerically, according to the newspaper. The Washington Post American.
Their life history traits, such as reproductive rates and rates of maturation and growth, are usually much slower. Thus, these animals become more vulnerable to extinction.
With the spread of humans, the average body mass of mammals in Eurasia fell by nearly half over the course of 100,000 years. In Australia alone, the average body mass of a mammal today is one tenth of what it was 125,000 years ago.
On the other hand, North America lags behind in terms of extinctions; Most of its large mammals survived until the end of the Ice Age. But when they began to become extinct, they quickly disappeared, which may be due to the discovery of Homo sapiens Homo sapiens) Long-range and more effective hunting weapons.
Impact of climate and environmental changes
Even during the massive changes in the planet’s climate, including the many ice ages and warm spells the planet has gone through, large mammals weren’t particularly vulnerable. The Atlantic American.
For her, her climate-induced extinction was also about whether humans were actually responsible for the loss of megafauna and meddling in the process..
Because when it gets warmer or colder, it won’t pick out bigger or smaller mammals and specifically target them, only when humans intervene, being huge increases the risk of your extinction and extinction..
According to . magazine Live Science Scientifically, Jessica Tudor of the University of Calgary says it can be difficult to analyze the effects of human hunting, climate change, and the dramatic changes that ecosystems are undergoing when large mammals and megafauna begin to disappear..
However, as Caitlin Maguire of the Orma J. Smith Museum of Natural History says: “While the extinction of megafauna is thought to have been the result of a dual punch from climate change and human influences, it is repeatedly clear to us that the human punch was stronger.
Even if climate change wasn’t primarily responsible for killing large mammals in the past, there are three very different things now: the climate is changing at an extraordinary rate because of humans; This change is of our own making now; Humans are also reducing the space available for wildlife and natural life.
It used to be that large mammals could deal with rising temperatures or shifting precipitation by constant movement and migration during the changing seasons..
Now, green spaces are constantly dwindling with the growth of cities and roads. These changes mean that modern humans have also become adept at killing the medium and small mammals that we know..
And after our ancestors killed mammals by hunting them or protecting themselves from their dangers. Now, we can indirectly drive the larger animals we know today to extinction by reducing their resources.
Today’s major animals are in danger of extinction
To date, the largest mammals remain in grave danger. Most of them live in countries with few resources, most of which suffer from conflict and poverty, according to the newspaper The Atlantic American.
For example, African elephants are heavily poached for sale. The northern white rhino became only female and all males became extinct.
Even giraffes are now threatened with extinction – their numbers have decreased by 40% in just 30 years, and they were moved to the Red List of Threatened Species in 2017. These dangers with the extinction of the largest animals we know today do not stop there.
Elephants and their relatives, for example, because of their diet prevent trees from encroaching on grasslands, and with the disappearance of mammoths from the ancient northern hemisphere, the grass-dominated worlds also became extinct. What predicts a similar scenario in the not too distant future.
If all currently threatened species became extinct, the largest mammal on Earth would be the domesticated cow. And all this because of man-made in the first place.