A LUMBERING reptile has stolen a march on us all. A study shows that New Zealand鈥檚 tuatara is the fastest-evolving animal known.
The tuatara, Sphenodon punctatus, is a 鈥渓iving fossil鈥�, virtually unchanged since dinosaurs roamed the Earth, says at the Allan Wilson Centre, Massey University. The tuatara takes 15 years to reach sexual maturity, reproduces only once every two to five years and has a slow metabolism.
However, when Lambert鈥檚 team analysed mitochondrial DNA sequences from 650 to 8000-year-old tuatara remains and compared them with those of living tuatara, they found that the reptile is evolving almost 10 times as fast as the average animal. It is accumulating an average of 1.37 substitutions per base pair every million years compared with an average of 0.2 (Trends in Genetics, ).
Advertisement
Marc Jones at University College London says it鈥檚 time for a rethink on the tuatara. 鈥淭his study should prompt us to take a closer look at the 鈥榝ossil鈥� animals to see if their anatomy is really as unchanged and stable as generally assumed,鈥� he says.
Evolution 鈥� Learn more about the struggle to survive in our comprehensive special report.
