Complex sentence: More recent studies using nuclear gene sequences, have found the presence of similar venom proteins in several lizards within the Toxicoferans, demonstrating that venom originated only once within the entire lineage approximately 170 million years ago.
Split into simpler sentences: More recent studies using nuclear gene sequences found the presence of similar venom proteins in several lizards within the Toxicoferans. This led to the theory that venom originated only once within the entire lineage approximately 170 million years ago.