What recent invention did carl woese use in 1970 to create his tree of life?

The correct answer will be - study of Ribosomal RNA (rRNA) genes using Polymerase chain reaction.

Explanation:

Carl Woese is known for his formation of a new tree of life based on the study of the evolutionary molecule called Ribonucleic acid.

He studied the genes of the ribosomal RNA and compared them and found a new group of an organism called Archaea.

Archea does not contain a nucleus and are similar to bacteria in appearance but the genetic differences of the genes of the ribosomal RNA excluded them from bacteria and eukarya ad were placed in archaea.

Thus, the study of Ribosomal RNA (rRNA) genes using Polymerase chain reaction.