One would have to be a cave dweller with no access to news, or choose not to tune into various news outlets, to not know that humans are all over the place. And, as we selfishly and ruthlessly expand our home ranges going anywhere we choose absent much concern for other animals or in some cases other humans, anthropogenic (human) effects are obvious and having devastating effects for a wide variety of nonhuman animals (animals) in all sorts of diverse habitats.
It's well known and well-demonstrated that we significantly change the behavior of animals when we trespass into their lives, including their sleep-wake and activity cycles, reproductive patterns, competition, dispersal, and foraging, but what about their brains? An excellent review of recent research can be found in a book called Behavioural Responses to a Changing World: Mechanisms and Consequences, edited by Ulrika Candolin and Bob B. M. Wong.
A recent essay in the New York Times called "As Humans Change Landscape, Brains of Some Animals Change, Too" highlights very interesting and significant research that further shows that indeed, our activities are behavior and brain-changers for a number of different animals. The abstract of the original research paper by Emilie C. Snell-Rood and Naomi Wick of the Department of Ecology, Evolution and Behavior at the University of Minnesota called "Anthropogenic environments exert variable selection on cranial capacity in mammals" can be seen here. It begins, "It is thought that behaviourally flexible species will be able to cope with novel and rapidly changing environments associated with human activity. However, it is unclear whether such environments are selecting for increases in behavioural plasticity, and whether some species show more pronounced evolutionary changes in plasticity. To test whether anthropogenic environments are selecting for increased behavioural plasticity within species, we measured variation in relative cranial capacity over time and space in 10 species of mammals. We predicted that urban populations would show greater cranial capacity than rural populations and that cranial capacity would increase over time in urban populations."
To test their hypothesis the researchers measured the cranial capacity of ten different mammalian species including mice, shrews, bats, and gophers in urban and rural areas. And, they did indeed discover for two species, the white-footed mouse and the meadow vole, individuals in urban populations had significantly greater cranial capacity (about 6%) than individuals in rural populations.
While much more research needs to be conducted on a wider range of species to see if individuals with larger brains are better learners and show increased behavioral flexibility that is related to their ability to survive, thrive, and reproduce in more challenging altered environments, this study is a wonderful beginning and calls further attention to the fact that we are not only game-changers for many other species, but also brain changers. And, what's extremely disturbing, is that we really don't know where all this will lead or end.