Genetics researchers have produced a new family tree for virtually every known bird species, using DNA analysis techniques to gain new insights into avian and evolutionary history.
The bird family tree was built by comparing the genomes of 48 bird species including the bald eagle, the common cuckoo, two kinds of penguin, the downy woodpecker and Anna’s hummingbird. These birds were selected to study because they were most likely to represent steps in the evolution of birds that led to most of the more than 10,000 known bird species.
However, since only three of the 48 bird genomes had been decoded before, 45 of the genomes were new.
The results of the research undertaken by 200 scientists from 20 countries worldwide were published last Thursday in the journal Science.
“Big bang” of speciation led to early split in bird family tree
The research suggests that an initial split in the bird family tree occurred around 68 million to 69 million years ago. One branch of the split evolved into to doves, flamingoes and a handful of other bird species, while the other branch evolved into 95% of the known bird species today. This surprisingly means that flamingoes are more closely related to pigeons than they are to pelicans or other water birds.
A second split followed shortly thereafter, enabling enough diversity that the resulting four lineages faced and survived the extinction 65+ million years ago that wiped out the dinosaurs, said lead author Erich Jarvis of Duke University and the Howard Hughes Medical Institute.
Evolution of birds — origins of bird song
Another important finding gleaned from the genetic data was that vocal learning, which is the ability to hear sounds and reproduce them (also an important feature of human speech), apparently evolved independently in several groups of birds. Also of interest, a brain region in song birds shares similarities with areas of the human brain related to speech
These song birds might be useful for studying what genes are involved in human speech disorders such as stuttering, noted study author Andreas Pfenning of the Massachusetts Institute of Technology.