Flamingo and Grebe May Be Sister Species

ByLee Dye

July 12, 2001 -- It's not often that scientists arrive at well-documented findings that are so contrary to common sense that they sit on them instead of publishing them because they figure no one's going to believe them anyway.

But that's sort of what happened to two independent research teams at Pennsylvania State University and the University of Wisconsin. Using very different approaches, the two teams studied the genetic nature of a wide range of aquatic birds, and some of the results were downright "astonishing," says evolutionary biologist Blair Hedges of Penn State's Eberly College of Science, leader of one of the teams.

For example, the elegant flamingo, with its stork-like legs, long neck and brilliant colors, turns out to have a really strange bedfellow in its family tree. The flamingo's closest relative, according to the researchers, is not another long-legged shore bird. It's a grebe.

The grebe is a duck-like bird with short legs designed for diving, and it doesn't look at all like a flamingo. Yet according to the researchers, the flamingo is more closely related to the grebe than it is to any other bird.

Turning Ornithology on its Head

If confirmed by further research, the findings indicate that the way we have grouped birds into distinct families, based generally on morphological traits like body structure and other similar physical characteristics, is wrong.

In other words, just because it looks like a duck, walks like a duck, and quacks like a duck, it's not necessarily a duck.

The research also suggests that evolution, especially among aquatic birds, has moved along at a much faster pace than had been thought, with many species developing similar characteristics — like webbed feet — independently, and at different times.

Of course, not everyone's convinced. Hedges himself admits the response among ornithologists has been one of "disbelief." That was expected, and it's one of the reasons the researchers waited several years to publish their findings, which finally appeared in the July 7 issue of England's Journal of the Royal Society.

And it might not even have appeared there if Hedges hadn't cleaned out his desk awhile back.

Hedges collaborated for several years with the late Charles G. Sibley, a world leader in ornithology, who was also fascinated with aquatic birds because their evolutionary history is so vague. Research results frequently conflict with other findings, leaving the field highly contentious.

Sibley was a leader in DNA research, even decades ago when most people knew virtually nothing about genetics, and his pioneering work earned him a membership in the National Academy of Sciences.

Hedges and Sibley collaborated on a number of research papers, but they remained particularly troubled by the flamingo. Even their early research, several years ago, suggested the flamingo was an odd bird indeed, closely related to the grebe.

Strength in Numbers

"It was really astonishing because there is no morphological trait that would even suggest that," Hedges says.

Fast forward a few years, and there's Hedges, cleaning out his desk and glancing over his correspondence with Sibley. One note from the grand old man of ornithology noted that his colleague, John A. W. Kirsch, got the same result using an entirely different technique.

"He didn't publish it because he thought it was so bizarre," Hedges says. "He thought there must have been some mixup."

Hedges had wondered the same thing about his own work, so he contacted Kirsch, who is now a professor of zoology and director of the Zoological Museum at the University of Wisconsin, where he has continued his research.

Hedges figured no one would believe just one of them. But there is strength in numbers, and since the two scientists had used different techniques, and different samples, and arrived at the same conclusion, it would be a bit harder to sweep the findings away.

Kirsch's lab used a technique called "DNA/DNA hybridization," which Sibley had pioneered. This technique compares all the genetic material contained in the DNA molecules of different species to determine the degree of genetic similarity. Hedges' lab used a technique called "DNA sequencing," which targets specific genes that carry the codes for inherited traits.

While the two techniques are quite different, the results were the same: the flamingo's sister is a grebe.

Webbed Feet Don't Make Relatives

The research also suggests that some birds that have been grouped together because of similar characteristics actually evolved at very different times. All birds with webbed feet, for example, did not inherit that trait from a single evolutionary event. The webbing that allows some birds to swim so effectively "appeared more than once" in the evolutionary history of aquatic birds, Hedges says.

The fact that an event that was thought to have occurred only once actually happened over and over again shows just how adaptable aquatic birds are, he adds, and it indicates that evolution could have moved along at a somewhat faster pace than had been thought.

If all of this is confirmed — and DNA research on aquatic birds is a very immature field — then many birds that look so much alike have erroneously been assigned to the wrong families. Hedges says it will take years to sort all of this out, and probably even longer to convince ornithologists who have become accustomed to seeing the world as it appears to be.

But just because it looks like a duck doesn't necessarily mean it's a duck.

Genetics is reshaping our view of just about everything these days. Nothing, it seems, is what it seems like on the surface. That's exciting, and a bit scary.

Unless, of course, you happen to be a lowly grebe who has just learned that you're very much like the beauty on the beach.

Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.

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