Bigger brained birds took to skies
4 Feb 2011 by Evoluted New Media
What can the flocculus tell scientists about flight, and did the dodo become flightless because its brain shrank? Aided by incredibly sensitive computerised tomography, Scottish and Canadian scientists hope to find out.
What can the flocculus tell scientists about flight, and did the dodo become flightless because its brain shrank? Aided by incredibly sensitive computerised tomography, Scottish and Canadian scientists hope to find out.
|
Raven (Corvus corax) skull showing the reconstructed brain. Credit: National Museums Scotland/University of Abertay Dundee |
The flocculus – a small part of the cerebellum responsible for integrating visual and balance signals during flight – allows birds to focus on objects moving in three dimensions while flying. Birds skulls grow to a fixed size before leaving the nest, with the brain almost completely filling the cavity – from this, the size of the flocculus can be worked out.
Scientists from the University of Abertay Dundee, University of Lethbridge in Canada and National Museums Scotland hope to follow the evolution of flight in birds by creating accurate 3D models of their brains using a CT scanner.
“By charting the relative size of parts of the avian brain we believe we can discover how the flocculus has evolved to deal with different flying abilities, giving us new information about when birds first evolved the power of flight,” said Dr Stig Walsh, senior curator of vertebrate palaeobiology at National Museums Scotland.
The scientists are able to create 3D virtual brain models – reconstructing the cavity inside the skull that housed the brain – and hope to discover whether a larger flocculus is directly linked to a greater ability to process visual and balance signals during flight.
They have analysed ancient fossils – including the only two skulls of a flightless sea bird preserved in soft clay around 100 million years ago – and modern bird skulls.
“This is a hugely exciting project,” said Patsy Dells Sterpaio, joint project leader from Abertay. “We hope this project can answer some of these important unresolved questions about the evolution of flight.”
The research may shed light on whether bird-like dinosaurs were truly dinosaurs or secondary flightless birds. The team will also look at flightless birds like the dodo to see if the flocculus became smaller with the loss of flight, believing that brain power required for flight was reduced in such species.
