This Island Spider That Deletes Half Its DNA, and Scientists Say It Shouldn’t Be Possible
The Daily Galaxy••science
Key Points:
- The island spider Dysdera tilosensis, found only on the Canary Islands, has a genome half the size of its mainland relative Dysdera catalonica, marking an unprecedented case of genome downsizing in an animal species.
- Despite its smaller genome (1.7 billion base pairs versus 3.3 billion in D. catalonica), D. tilosensis maintains greater genetic diversity, contradicting the typical expectation of reduced diversity in isolated island populations.
- The study challenges traditional evolutionary assumptions that island species expand their genomes due to reduced selection pressure; instead, D. tilosensis shows genome shrinkage through a process of streamlining by eliminating non-functional DNA.
- Chromosome numbers differ between the species, with D. til
