Cows could be the biggest mammal left thanks to hominins’ love of hunting
Centuries ago, big mammals ruled the hinterland. There was the megatherium, a ground sloth that was as big as an African elephant, and there was the daeodon, a giant pig that weighed thousands of pounds and would probably give the fictional Okja a run for her money.
Sadly, these massive mammals are no longer with us, having been drawn to extinction. While it’s widely believed that extinction has been caused by climate change, it instead might actually be due to Neanderthals and humans’ love for hunting megafauna, according to a new study published in the journal, Science.
Things are now so bad that Felisa Smith and her team from the University of New Mexico believe that the last ever large mammal alive will be the placid domestic cow.
The researchers analysed 65 million years of mammalian fossil data on each of the continents. They looked at mammal prevalence, extinction and diversity at one-million year intervals. Then, separately looking at the 125,000-year period when humans migrated out of Africa, the researchers were able to find some pretty stark and depressing results.
According to the team’s findings, humans targeted larger species rather than smaller rodents. In every continent humans had migrated to (bar Antarctica), the average body mass of mammals had decreased.
“This suggests archaic human influences on mammal diversity, body size and the number of mammals,” Felisa Smith, lead author of the study, told Mashable. “The only time being big is bad is when humans are involved.”
As humans branched out to different continents, the body size of mammals continued to get smaller and lighter.
“There is a very clear pattern of size-biased extinction that follows the migration of hominins out of Africa,” Smith added when talking to Reuters.
There are a number of large mammals currently on the endangered list. The giraffe, for example, once thought to be safe from endangerment, was placed on the list in 2016. We even lost our last ever white male Rhino last month.
“The only reason why we’ll have something as big as a cow is because we like cows – they’re domesticated,” Smith told Mashable. “Mammal extinctions are rarely synonymous with climate but are always synonymous with human arrival.”
Extinction is unfortunately a very likely scenario. According to a study conducted by researchers from Princeton University back in 2015, mammal extinction rates over the last century have increased tenfold, and we’re now entering a “sixth mass extinction”.
With the knowledge that we have an active hand in mammal extinction rates, it does at least give us an opportunity to do something about it. But given past form on matters such as climate change, I wouldn’t hold my breath.