Lizard limb loss may be rapid evolution

ADELAIDE, Australia, Nov. 10 (UPI) -- Australian scientists say they have determined small skink lizards are losing their limbs through rapid evolution.

The small skink lizard, Lerista, demonstrates extensive changes in body shape over geologically brief periods, the University of Adelaide scientists said, noting several species of the skinks have quickly evolved an elongated, limbless body form.

Many species of skinks have limbs that are either reduced or missing entirely.

"It is believed that skinks are losing their limbs because they spend most of their lives swimming through sand or soil; limbs are not only unnecessary for this, but may actually be a hindrance," said Adam Skinner, lead author of the study.

Skinner and his colleagues performed a genetic analysis of the lizards and discovered evolution of a snake-like body form has occurred not only repeatedly, but also very rapidly and without any evidence of reversals.

"At the highest rate, complete loss of limbs is estimated to have occurred within 3.6 million years," Skinner said. "Compared to similarly dramatic evolutionary changes in other animals, this is blisteringly fast."

The study is reported in the journal BMC Evolutionary Biology.