Monday, February 27, 2012

Flamingos & Grebes

Watching a flamingo navigate the shallows of an ephemeral lake, one would surely conclude that it is closely related to storks, herons and ibis; yet, placing this bird on the tree of avian evolution has long been a subject of controversy. By late in the 20th Century, fossil evidence from across the globe seemed to suggest that flamingos are a hybrid between shorebirds and waterfowl; indeed, they harbor the same feather lice that are found on ducks and geese. The fossil evidence also revealed that, despite their current concentration in tropical and subtropical life zones, flamingo species were widely dispersed throughout temperate regions before the Pleistocene Ice Age.

Then, within the past decade, molecular geneticists discovered that flamingos are, in fact, most closely related to grebes. This finding sent a shock wave through the world of avian biologists, especially given the obvious differences in the appearance and behavior of those bird groups. Nevertheless, morphologic studies have since confirmed that flamingos and grebes are, indeed, sister species.

While controversy continues to smolder, this story highlights the role of science throughout human history. Originally convinced that we lived on a flat landscape around which the sun, moon and stars revolved, we later learned, through scientific investigation, that we live on a smallish globe on an outer band of a massive galaxy that is one of billions of galaxies in our Universe. Despite the constant protestations of religious groups, we have also unraveled the mysteries of evolution, plate tectonics, genetics and astrophysics, among others. Throughout this ongoing process of discovery, human assumptions and beliefs have repeatedly dissolved in the wake of scientific progress.