Deductive reasoning generates the conclusion that because we are here to think about and ask questions about the first living thing on Earth,it must have existed.This first living thing presumably gave rise to multiple lineages,at least one of which served as the ancestor for all of life on Earth.The acronym IDA has been applied to the first living thing,and LUCA to the ancestor that gave rise to all of life.What do IDA and LUCA stand for?