Human influence is thought to be driving declines in biodiversity. Extinction rates could be some 1,000 times faster than they were before humans showed up. Some models suggest we've already lost as much as 7 percent of known species.
And as the climate shifts, animals and plants could find it even harder to adapt. Extinctions could grow more common.
Plus, while we've created new species thanks to domestication and our movements around the globe, those species don't have the same genetic diversity as ones that have just now died out after millions of years.
In any case, impact on these animals will eventually make its way into the geological record. Whether it gets its own name or not, some of the first fossil evidence of overall human influence on the planet will be the bones of the domesticated chicken.