Ecosystems as the unit of evolution

From Darwin's Unfinished Symphony: How Culture Made the Human Mind by Kevin N. Laland, page 6.

At the heart of this challenge was the undeniable fact that we humans are amazingly successful species. Our range is unprecedented; we have colonized virtually every terrestrial habitat on Earth, from steaming rainforests to frozen tundra, in numbers that far exceed what would be typical for another mammal of our size. We exhibit behavioral diversity that is unparalleled in the animal kingdom, but (unlike most other animals) this variation is not explained by underlying genetic diversity, which is in fact atypically low. We have resolved countless ecological, social, and technological challenges, from splitting the atom, to irrigating the deserts, to sequencing genomes. Humanity so dominates the planet that, through a combination of habitat destruction and competition, we are driving countless other species to extinction. With rare exceptions, the species comparably prosperous two humans are solely our domesticates, such as cattle or dogs; our commensals, such as mice, rats, and houseflies; and our parasites, such as lice, ticks, and worms, which thrive at our expense. When one considers that the life history, social life, sexual behavior, and foraging patterns of humans have also diverged sharply from those of other apes, there are grounds for claiming that human evolution exhibits unusual and striking features that go beyond our self-obsession and demand explanations.

Laland makes a point that is usually unremarked upon though occasionally is implicit. It is not only humans who are successful as a species, it is the human-created ecosystem which is successful.

That relates to the unresolved debate in biological circles - where do the Darwinian forces and selections occur? Dawkins argues that it is the selfish-gene. Darwin tackled this from the point of view of the individuals within a species. There are others who argue that it is at a group level within a species, usually when discussing humans (survival of the fittest communities, cultures, institutions). Laland, intentionally or not, raises the game to the next level: not genes, not individuals, not communities; mutually dependent ecosystems. The possible reading of his words is that codependent ecosystems might be considered a unit of evolution.