How spiders got their knees

Noted: Still, there are other arachnids like mites that have kneecaps but no copy of the Dachshund gene, says Prashant Sharma, an evolutionary biologist at the University of Wisconsin, Madison, who was not involved in the work. “Reconciling how that occurs is something the study needs to grapple with before it can claim that one particular gene copy explains how all arachnids have patellas.”