SOS:
The answer is <u><em>genetic recombination!</em></u>
<em>Hope this helps!</em>
Answer:
Some tadpoles develop a chronic ilnness called yuraspasticitis causing decreased growth rates.
Explanation:
Yuraspasticitis is a common issue in the tadpole population of high tadpole density ponds. It is caused by a bacterial penetration of the urass gland.
It's harder to find one of the many genes involved in a polygenic trait vs the only gene involved in a discrete trait.