Texas Tech Biologist Leads Team of Scientists in Mapping Crocodilian Genomes
A Texas Tech University biologist is the leader of a team of more than 50 scientists who mapped the genomes of three reptiles in an attempt to discover more about the evolution of birds.
Associate Professor of Biology David Ray and the others’ research, funded by the National Science Foundation, was printed in the peer-reviewed journal Science on Friday, December 12.
Ray and the others completed genomes of a crocodile, alligator and true gharial as part of their ‘genomic family portrait’ because the crocodilians are some of the closest living relatives to birds.
“Technically, birds’ closest relatives are the dinosaurs,” said Ray. “So we can only look at their fossils and this can provide only limited information on their biology when compared to examining organisms that are alive today."
Ray said a major finding of the project was that the crocodilians genomes change very slowly over time when compared to avian genomes.
“We compared both birds and crocodilians to turtles, which are the closest living relatives of the group that includes both birds and crocodilians. We found that they evolved slowly also,” Ray said. “The best explanation for this is that the common ancestor of all three was a ‘slow evolver’ which in turn suggests that rapid evolution is something that evolved independently in birds.”
Initially, Ray’s team intended to map only one percent of the crocodilian DNA when they began the project back in 2009. During the process however, the price of mapping one million bases dropped from $1,000 to $1 and the team was able to fully map the animals.
More than 3 billion genome bases were mapped.
The researchers report the mapping of the genomes is just the beginning. Assistant Professor of Biomolecular Engineering at the University of California, Santa Cruz, said researchers are now in a unique position to search for the common ancestor of the crocodilian and aviary families.