You can infer that the birds once had a common ancestor but became separated. Mutations in copying their genes stacked and caused changes in the beaks so the birds could be more well off or better adapted in their new environment.
An atom is unlikely to react when it is stable. That is when it's shell is complete. Due to the completion of the shell, no other electron can combine through any form of bonding. Hope i helped.
From nucleic acid to amino acid apex i think
