Why do emus have wings

But their palate bones match the ratites. Where do they belong? Scientists have debated this question for years. Now, a new study in the journal Molecular Biology and Evolution , analyzing the largest molecular dataset to date, clarifies the tinamous' place on the evolutionary tree and offers clues about the origins of flightlessness.

To sort out the details, scientists probed almost 1, DNA segments from tinamous, emus, ostriches, the extinct little bush moas, and others. After sandblasting and pulverizing an ancient moa toe bone to chemically extract and sequence the DNA, scientists compared its DNA with that of the other species and ran multiple computer models simulating molecular evolutionary changes. Some earlier studies, which have generally showed tinamous on the outskirts of the ratite group, relied solely on morphological traits like skeletal details.

Other investigations of limited genetic information suggested tinamous were evolutionarily tangled with the flightless birds. The results were staggering, Baker says. The tinamous evolved within ratites, not as a separate lineage. Moa breastbones, toe bones, leg bones, and even the occasional skull rested in the mud, the final resting place for birds chased and slaughtered by humans about 12, years ago.

Today, a cast of a Dinornis robustus skeleton towers over visitors to the Royal Ontario Museum where Baker is the senior curator of ornithology. The tinamous' place on the evolutionary tree offers a glimpse into the origins of flightlessness. All ratites, including tinamous, probably trace their ancestry back to a flying relative, according to Baker. Tinamous retained their ability to fly, while the other lineages each lost flight independently.

The study upends an alternate, oft-cited story. Scientists speculated that the breakup of the supercontinent Pangaea's southern section split up a population of flightless ratite ancestors.

Loss of wings most probably occurred in a beetle species that colonized a windy island. Again, this is a loss of genetic information, so it is not evidence for microbe-to-man evolution, which requires masses of new genetic information. The wings have a function. But they managed to survive and reproduce, because the threat was gone. Simon Foden has been a freelance writer and editor since He began his writing career after graduating with a Bachelors of Arts degree in music from Salford University.

He has contributed to and written for various magazines including "K9 Magazine" and "Pet Friendly Magazine. Vestiges can also be found at the molecular level.

Nipples of male mammals, for example, probably never had any function. They persist, however, due to the genetic blueprint shared by all human foetuses—and because there is no particular harm in them hanging around. The important thing to realise is that evolution is still happening right now.