2. The length of lines seen on phylogenetic trees represents the amount of change. The longer in length means a larger amount of change. The branching pattern represents a common ancestor among species. Although commonly misinterpreted, the tip proximity does not indicate any relatedness of organisms.
3. Yes, all organisms found on a phylogenetic tree are equally evolved. Every organism has a common ancestor from several billions years, each organism would have been evolving on earth equally through that time.
4. Science use collected data to figure out shared or derived characters to group organisms into clades.
5. Homologous traits