Chemical reactions convert to . In nonliving systems, the presence of a(n) allows the reaction to proceed very quickly and have a lower . In living systems, this function is carried out by proteins called . activation energy
catalyst
enzymes
products
reactants

for example, no new evidence will demonstrate that the earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the earth is not divided into solid plates that have moved over geological timescales .

on island x the species needed to adapt because they were being subject to predators which didn't inhabit island y.