A very large dataset is offering a different picture:
Wild populations must continuously adapt to environmental changes or risk extinction. For more than fifty years, scientists have described instances of “rapid evolution” in specific populations as their traits (phenotypes) change in response to varying stressors. For example, Spanish clover has developed a tolerance for copper from the mine tailings in which it grows, and the horn size of Alberta bighorn sheep has decreased due to trophy hunting. But until now it hasn’t been possible to reach any overarching conclusions about how different factors (such as harvesting, climate change, invasive species, or pollution) shape this rapid (now called “contemporary”) evolution.
Building on earlier work, a McGill University-led team has created a massive new dataset of close to 7,000 examples of changing traits in various populations around the world, from house sparrows and gray wolves to freshwater snails and Canadian goldenrod. The dataset is 80% larger than any that existed in the past and documents trait changes that are a mixture of evolution and immediate (plastic) responses to the environment.
“We have come a long way from the old view of evolution as a slow process to the point where we are now realizing that everything is evolving all around us all the time,” says Andrew Hendry, a Professor of Biology at the Redpath Museum of McGill and the co-senior author on the paper recently published in Molecular Ecology.McGill University, “Uncovering the underlying patterns in contemporary evolution” at ScienceDaily (January 19, 2022)
This is valuable information but that which changed quickly before can probably change just as quickly back. Whether we end up with evolution in the traditional sense of an irreversible trajectory is going to take a while to sort out.
The paper is closed access.
You may also wish to read: Are humans changing evolution? Like tuskless elephants… In a human-dominated world, things happen faster, for better or worse. Should we still call it “evolution” if we did it?