Answer:
This term was created by Charles Darwin based off his research on evolution
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.
For continued survival
animals gotta eat
Our elbow bends all the time, we bend it when we pick up things, when we eat, when we do mostly everything. Cows on the other hand dont pick up food with there feet, they use there mouths, and they probably only bend when they are walking.
No estoy seguro que decir, pero sí es difícil