http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi may not have the latest greatest data, but pleasant to use. My original question about the path from Homo Sapiens (Humans) to Zea Mays (Maize) is answered almost immediately, it is got by gluing these two paths (49 nodes in all) 1. Eukaryota; Viridiplantae; Streptophyta; Streptophytina; Embryophyta; Tracheophyta; Euphyllophyta; Spermatophyta; Magnoliophyta; Mesangiospermae; Liliopsida; Petrosaviidae; commelinids; Poales; Poaceae; PACMAD clade; Panicoideae; Andropogonodae; Andropogoneae; Tripsacinae; Zea 2. Eukaryota; Opisthokonta; Metazoa; Eumetazoa; Bilateria; Deuterostomia; Chordata; Craniata; Vertebrata; Gnathostomata; Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Euarchontoglires; Primates; Haplorrhini; Simiiformes; Catarrhini; Hominoidea; Hominidae; Homininae; Homo and you can click on any of those words, e.g. "Craniata" to learn more. The amount of info inside this thing looks immense. About http://www.onezoom.org/ Currently omits the bacteria, far as I can tell? However they claim by the end of 2015 they will interface this to the full Open Tree of Life Project dataset with over 2 million species.