Answer:
Homologous structures provide evidence for common ancestry analogous structures show that similar selective pressures can produce similar adaptations beneficial features Similarities and differences among biological molecules in the DNA sequence of genes can be used to determine species relatedness
Energy is ever-existing - energy does not disappear or is not created from nothing. Energy is only transferred from one system to another. Energy is only transformed from one type/form of energy to another type/form of energy. So, the energy of a system is either converted into another type of energy in that same system or is extinct to another system.