In fact, the influence of humans practically engaged in subsistence survival within their local landscape, over the last 3 or 4 millennia has so radically changed almost every biome in existence that it could be claimed that there is no natural world, other than in the genuine wilderness of Antarctica.
The myth of the wilderness chimes strongly with Americans - unpopulated unpolluted vast stretches of land untouched by man.
Underpopulated yes, given that during the European invasion, the aboriginal population suffered a mortality rate from smallpox and persecution of -estimates vary - about 95%. Certainly, where Columbus landed in Hispaniola, modern day Haiti and Dominican Republic, we know that 100% of the natives had died out by around 1650CE. IIRC, it is estimated that the population of the Amazon was reduced by 95%. In the States, the official government policy was "extermination" until late into the 19th Century. And one of the main arguments advanced for the second amendment was so that private citizens could join in.
In the New World then, as well as the old, if you are intent on setting aside space for nature which has never been affected by humans, there isn't any.
Back in Europe, which I know better... My own idiosyncratic belief is that the greatest threat to local biodiversity in the UK, for example, is now UNDERpopulation.
By which I mean that the current rural population is not much bigger or smaller than it was 50 or 100 years ago, and whether it is bigger or smaller make little difference. But people no longer make any use of virtually any local natural resources. As far as the natural world is concerned, after at least 2,000 years of human exploitation, the humans disappeared, and that is a disaster.
If, to take an example pertinent to the discussion above, woodland is no longer coppiced to provide firewood and timber, you do still get some standing woodland; but it enormously impoverished as a habitat. In a purely "natural" state, in a now near mythical, unrecoverable past, which is now the preserve of Disney movies, there was some mature woodland, but with an awful lot of clearings in it. Because mastodons sometimes decided they preferred their lunch to lie down and not hover out of reach. Thus, biologists speculate, certain tree species evolved to survive being broken, or even felled and nearly uprooted. by producing new coppiced growth. There are also a wide range of woodland plants which have evolved to exploit the break in the canopy, on which a host of creepy-crawlies also depend. Once upon a time, the mastodon and the other mega fauna may well have been the "keystone" species in this environment.
Their role was inherited by a bunch of medievals, who certainly weren't even aware of why a tree can be coppiced, nor slightly interested in providing ecological niches for bluebells or butterflies; but who did so because the found it was the best way to obtain the maximum amount of wood from a patch of land. In modern terms, the best source of carbon-neutral fuel.
Similarly, not with the specific aim of pleasing the reed-warblers, reed beds were ransacked for every last standing reed, for thatch or basketry, on an annual basis. Reeds grow better if they are cut. Once upon a time, not so long ago, people around here even picked fruit off fruiting plants when they were bearing ripe fruit.
From such practices, the English landscape was largely formed, and in terms of the pattern of land-use, changed remarkably little between the late Bronze Age and the witterings of the Reverend Malthus in around 1800, when the situation gravely changed, due to the actual Tragedy of the Commons, rather than the mythical version referred to by Neven, above; which I may return to in a future instalment.
My point, for this instalment, is that the environment which was handed down to us by our ancestors was actually shaped by their exploitation of it; and while they may have a bit too good a job at, for example, supplying the beaver-skin hat market, or the wolf-skin cloak department, which is regretable, many of those species which actually survived a couple of millenia of living alongside humans actually thrived as a result of humans performing important, long-sighted and sustainable activities within it, and performing crucial ecological roles within it.
To impose a boundary between the human and the rest of the natural world, and to declare humans the enemy of the natural is to condemn many habitats which now only exists specifically because of human intervention to a long slow decline through neglect.
Those sources of natural resources and produce within Western Europe, at least, which were at genuine risk of extinction through overexploitation by people are long gone. Like Julius Caesar ate the last one, the greedy sod. There are many more in the actual modern world as it exists that are in more danger today because humans are now afraid to interact with their surroundings in any way, for fear of upsetting a "natural" ecological balance that actually irrevocably disappeared several tens of thousands of millennia ago.
I accept that Antarctica is a wilderness, and that humans have no business there, apart from on important scientific work. But Antarctica is not a hotspot of biodiversity, more of a desert. People have always tended to avoid deserts, preferring areas of high biodiversity, which is often tasty or of other interest. We are locked in a symbiotic relationship with our environment; and the continuing economic exploitation of the environment by humans is an essential feature of that relationship; without which both parties locked in symbiosis suffer immensely.