The basic steps of light-dependent reactions are:
• Light absorption in Photosystem II (PSII) and excitation of PSII
• ATP synthesiS-proton gradient in electron transport chain isdriving ATP production in a process of chemiosmosis
• Light absorption in Photosystem I (PSI) and excitation of PSI
• Reduction of NADP+ and the photolysis of water.
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.
Clues such as fossils such as bones, footprints, tar, etc, preserved underground helped inform scientists. You can also count how old a tree is when you cut it open and there are some alive for thousands of years so that is a possible way.
Ribosomes; they assemble proteins together.
