Whenever I read the word “study” in a article, I become skeptical. Most of these studies are worth nothing, and are just done in order to obtain more grant money.
There were not enough humans over the past 100000 years to affect anything on the Earth.
The same is true today.
One thing these a$$hole$ don’t get. Humans are as much a part of the ecosystem as cockroaches. Humans are not unnatural. We are part of the Earth.
Why is it that these people are ashamed of being human?
Maybe it's because these people are creeps.
The fact is that humans have driven many species to extinction. Its not shame at being human its just what it is. More often than not they’ve been specialized populations or limited populations. Think Dodo birds, the Great Auk, Irish elk, or passenger pigeons. Hunting pressure, loss of habitat, introduction of predators, all take their toll.
On the other hand, we’ve brought some species back from the brink of extinction that were likely dying out all by themselves. The California condor doesn’t appear to have ever existed in any great numbers and would likely go extinct within a few decades if it weren’t for deliberate human intervention.
Other species like the Kirtland warbler have been brought back from the brink because of humans doing what humans do. In the 50s there were only a couple dozen breeding pairs that existed in a couple dozen square miles of northern Michigan. Today they’re found across the northern 3rd of the lower peninsula, across much of the upper peninsula and into northern Wisconsin. They rebounded because of things like logging, clearing of land for oil and gas exploration, forest fires both natural and controlled. They won’t nest anywhere but in new growth jack pines of a particular size.
We nearly wiped out the buffalo but I suspect the indians would have done the same given enough time. Running whole herds off of cliffs was a particularly wasteful means of hunting.
As far as the megafauna are concerned, my guess is that the naturally changing climate did the most damage and wiped out the most species. Humans appearing on the scene probably did finish off a few species. Its also important to note that new species arrived at the same time as humans and would have damage of their own.