Evolution would imply superior fitness level, some kind of benefit for said organism to survive better.
This would be a defect because it looks to be impacting how this animal live as its hind leg appears to be backwards.
Without wings this organism also has a hard time jumping over obstacles like other chicken.
You are mixing up defect with mutation.
A genetic mutation is a precursor to evolution assuming the mutation has some positive benefit. If not it would be a defect and leads to less survivability.
That would be calling Down Syndrome evolution of human species except Down Syndrome sufferers are sterile and have severe cognitive impairment that would make their lives very difficult without modern intervention.
527
u/Lou_LL_11 29d ago
Genetic defect is just another word for evolution.