The genetic code links groups of nucleotides in an mRNA to amino acids in a protein. Start codons, stop codons, reading frame.
It can benefit the bird by being light enough to glide around in the air. It can also help the bird by giving it the lightweight body structure to get away from danger in a speedy manor.
Answer:
If one animal's population increases, the population of animals that eat that animal might also increase. Increases in population aren't always beneficial.
Explanation:
Sometimes a population will grow too large for the environment to support. Other changes in limiting factors can cause a population to decrease.
source: NHPBS