Evolutionary homogenizing

Source: https://www.science.org/content/article/most-distinctive-birds-are-ones-most-risk-extinction

It’s bad enough that Earth could be losing thousands of species each year. Now, two independent studies of birds have concluded the ones most likely to disappear are those that serve unique—and possibly irreplaceable—functions in their ecosystems. Consider the toucan: Its iconic beak lets it eat and disperse seeds and fruit too large for other birds in South American rainforests. Yet these striking creatures, as well as vultures, ibises, and others with distinctive physical traits, are likely to be the first to go extinct, homogenizing the avian world, according to one study. A second paper predicts communities will grow more alike as species flock to cooler regions in the face of climate change.

“That’s alarming because we know that diversity of sizes and shapes and behaviors is a signature of a healthy community,” says Scott Edwards, an evolutionary biologist at Harvard University who was not involved with the work. “This is laying out the grim world we are going to be facing.”

He and others hope the papers will spur conservationists to think more broadly about what biodiversity means. “The impacts of human actions can actually be worse than what we might think just based on species tallies alone,” says Jedediah Brodie, an ecologist at the University of Montana, Missoula. “We haven’t focused on what kinds of functions we might be losing,” adds Marta Jarzyna, a macroecologist at Ohio State University.​

This makes a lot of sense. A similar trend appears in domesticated flora and fauna.

Bob Wilson