But share only eight gut microbes with their closely related cousins, the ringtail lemurs. This is not a neat Darwinian picture.
“The bamboo lemur’s evolutionary tree diverged from that of both panda species 83 million years ago — that’s 18 million years before dinosaurs went extinct,” says Erin McKenney, a postdoctoral researcher at North Carolina State University and lead author of a paper on the study. “These species are also separated by thousands of miles and the Indian Ocean. Red pandas and giant pandas aren’t closely related either, with their most recent ancestor coming 47.5 million years ago. Lemurs are primates, red pandas are related to raccoons, and pandas are related to bears.
“Yet all three species share these 48 gut microbes — more than 12 percent of the microbial types found in each species’ gut,” McKenney says. “The only common feature is their diet: all three species live almost exclusively on bamboo.”
Bamboo is not easy to eat. It is physically tough, difficult to break down, and is not especially nutritious. In order to thrive on a bamboo diet, an animal needs some help in breaking down the fibrous material to get the necessary nutrients. And that’s especially true for animals with simple guts — like the bamboo lemur, red panda and giant panda.
Of the 48 microbes found in common, some are also found in other animals fond of fiber-rich diets. For example, several are also found in cows, and one is found in termites. This suggests that these microbes play a role in breaking down fiber to extract nutrients.
“This really underscores the role that diet plays in determining what lives in our guts — and, in turn, how these microbial ecosystems can shape the way animals live,” McKenney says. Paper. (paywall) – Erin McKenney et al. Bamboo specialists from two mammalian orders (Primates, Carnivora) share a high number of low-abundance gut microbe. Microbial Ecology, 2017 More.
Findings like this offer a caution flag for sweeping generalizations based on ancestry. Ancestry may not be as important as we think in evolution.
See also: Stake in heart of school Darwinism lesson: Bilaterian nerve cords probably evolved many times
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