Island spider sheds half its genome, defying evolutionary expectations

science • 10/13/2025

Over a few million years, the spider Dysdera tilosensis—a species endemic to the Canary Islands—has reduced the size of its genome by half during the process of colonization and adaptation to its natural habitat. In addition to being smaller, this genome is more compact and contains more genetic diversity than that of other similar continental spiders.

Over a few million years, the spider Dysdera tilosensis—a species endemic to the Canary Islands—has reduced the size of its genome by half during the process of colonization and adaptation to its natural habitat. In addition to being smaller, this ge... [5585 chars]