February 28, 2002. Copyright 2002. Graphic News. All rights reserved. Embargoed until 14:00 Eastern U.S. (19:00GMT) Thursday, February 28, 2002 PICTURE CAPTION: GN13498 -- Skull of a dodo specimen on display at the Oxford University Museum of Natural History. DNA analyses confirm that the closest living relative to the dodo (Raphus cucullatus) is the Nicobar pigeon (Caloenas nicobarica). MUST CREDIT: Alan Cooper and Beth Shapiro ------------------------- The long and lonely road of the dodo LONDON, February 28, Graphic News: The preserved dodo thought to have provided the inspiration for Lewis CarrollÕs dodo in Alice in Wonderland has also shed some light on the speciesÕ evolutionary history. The dodo and another flightless island bird, the solitaire, died out centuries ago, leaving naturalists puzzled as to where they fit on the evolutionary tree. New research published in the March 1 issue of the journal Science indicates that both extinct birds are sister taxa (species), and that they are nested -- no pun intended -- within the pigeon family, the Columbiformes. DNA analyses from the skull and leg of a dodo specimen on display at the Oxford University Museum of Natural History confirm that the closest living relative to the dodo (Raphus cucullatus) is in fact the Nicobar pigeon (Caloenas nicobarica). The Nicobar Islands lie about 3,100 miles (5,000 kilometres) west of the Indian Ocean island of Mauritius, the historic land of the dodo. Beth Shapiro and colleagues at the University of Oxford and the Natural History Museum in London extracted mitochondrial DNA (mtDNA) from 37 species of pigeons and doves, including preserved specimens of the dodo and solitaire. The DNA from mitochondria, the cellÕs energy-producing organelles, are maternally inherited, so genetic variation arises largely from mutation alone. And because mutations have generally been thought to occur randomly and to accumulate at a constant rate, the date for a common mtDNA ancestor can be calculated. The short mtDNA fragments were ampified by polymerase chain reaction -- a technique that mimics natureÕs way of replicating DNA -- to make millions of copies so it could be examined in the laboratory. ShapiroÕs researchers found that the dodo and solitaire diverged from the Nicobar pigeon and its sister taxa, the New Guinea crowned pigeon (Goura) in the mid- to late-Eocene epoch about 42.6 million years ago. The dodo diverged from the solitaire much more recently, during the late-Oligocene period, some 25.6 million years ago. But how did the two species finally arrive on the Mascarene Island group? The dodo has only been found on Mauritius, and the solitaire on Rodrigues, 370 miles (600 kilometres) to the east. Geological evidence has established that ridges surrounding the Mascarene Plateau and the adjacent Chagos-Laccadive Plateau were above sea level in the late-Oligocene -- when India was gradually moving away from Antarctica towards Asia. The researchers suggest that the birds may have used the Mascarene island chain as Òstepping stonesÓ before eventually settling on their respective islands. Why the dodo made its long march to Mauritius remains unclear, but after some 40 million years the friendly, flightless bird finally met up with humankind. In the 1580s, when dogs and pigs were brought onto the island, things changed drastically. Man started hunting the bird and within a century the dodo became extinct: ÒTut, tut, child,Ó said the Duchess to Alice. ÒEverythingÕs got a moral if only you can find it.Ó /ENDS Sources: Science, Natural History Museum, Mauritius Wildlife Foundation