Urban Lizards Are Divergent

Researchers in Puerto Rico have determined that lizards living in urban environments are genetically different from their forest dwelling relatives.  The crested anole (Anolis crestatallus), a brown lizard with an orange throat fan has developed special scales to allow it to scoot across smooth surfaces like walls and windows, while also developing longer limbs.  Scientist Kristin Winchell of NYU, lead study author, is watching evolution in action.

Her study looked at 96 Puerto Rican crested anoles, comparing the genome of lizards still dwelling in forest and those living in three cities including San Juan.  The researchers found 33 genes repeatedly associated with urban living.  The morphological difference appeared to be mirrored by the genetic changes.  The life span of the lizards is around seven years, but genetic changes can occur quickly, within 30 to 80 generations.  The alterations to their genetic codes allow urban lizards to adapt to urban conditions: longer limbs make them faster, and special scales help them to hold to smooth surfaces.  The study focused on male lizards, so it is unknown at this point whether female lizards are also changing.  If the adaptations allow males to breed more successfully, then the traits will be passed on to future generations which allows natural selection to take affect.

One of Winchell's favorite findings is an albino anole that is larger than normal (8 cm).  She named him "Godzilla", which is appropriate since we know Godzilla to be the "king of monsters"