> But all lifeforms

That's not nessisarily true. Single celled organisms have a rather fluid exchange of genetic information even our 'single cells' are really several different organisms. It's possible life evolved many times on earth and current single celled organisms and thus all life has a mismatch of ancestors.

Further, life may regularly evolve even today, but simply get eaten due to the stiff competition.

PS: We know life evolved at least once, but the high end could be multiple times a second on earth.