Not every line of scientific enquiry will make your teeth whiter or improve the gas mileage on your car, but that doesn't render scientific endeavors that don't deal with optimum petroleum efficiency or dental cleanliness entirely worthless. Where the value in a specific enquiry lies can be hard to pin down for the everyman, though, especially if news stories about said research don't make that clear.

For their tuatara genome sequencing project, a group of scientists in New Zealand are cutting out the middleman and blogging their way through their research. Their first post is "Why sequence the tuatara genome?" So, straight from the horse's mouth, here's why they're looking at the genome of lizards' cousins (SPOILER ALERT: Evolution).

To understand why a tuatara genome is such a tantalising prospect for scientists you need to know how the tuatara relates to other reptiles. All life on earth is connected by a shared evolutionary history. When biologists try to organise the diversity of life on earth, we reconstruct that history by finding groups of species that all descend from a shared common ancestor. 

You sometimes hear people mistakenly call tuatara "living dinosaurs".  In fact, as you can see in the figure above, tuatara are much more interesting than that. If you want to study a living dinosaur you only need to look out the nearest window. Modern birds descend from one branch in the diverse group we call dinosaurs, but each of those ten thousand species are dinosaurs. The tuatara, on the other hand, are the only living members of a lineage that separated from other reptiles more than 200 million years ago.

By placing modern organisms in the context of their evolutionary history, we can work out which traits were present in ancestral species, and reconstruct the changes that gave rise to modern ones. As the tuatara is the only living witness to hundreds of millions of years of evolution, its genome sequence will be immensely valuable in understanding the genetic changes that have allowed reptiles to evolve and diversify.

In fact, even the tiny amount that we already know about tuatara genetics has helped us understand not just the evolution of reptiles, but how mammals (like us) have evolved. [Sequencing the Tuatara Genome]