1. What would be the percentage of the non-singing trait in female birds in Generations 4 and 5 if this pattern continues?
2. In which generation will there be almost 100% non-singing females if there are no changes in the
birds’ environment and interactions?
3. In what possible scenario would the female birds evolve to having the singing trait?

Ты не знаешь ни английского языка

It would be the equator.

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.