because the energy that comes from burning fossil fuels is converted into electricity and heat in power plants. When fossils are burned, carbon and hydrogen react with oxygen to produce carbon dioxide (CO2) and water (H2O) during this reaction heat is produced
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.
