The story
- Proto-Indo-European*bʰeh₂-
- Proto-Indo-European*bʰéh₂os
- Proto-Hellenic*pʰáwos
- Ancient Greekφᾰ́ος (phắos)
- Ancient Greekφῶς (phôs)
- Ancient Greekφωτο- (phōto-)
- Englishphoto-
- Proto-Indo-European*gʷeyh₃-
- Ancient Greekβίος (bíos)
- Proto-Indo-European*leǵ-
- Proto-Indo-European*lóǵos
- Proto-Hellenic*lógos
- Ancient Greekλόγος (lógos)
- New Latinbiologia
- Englishbiology
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- Englishbiological
- English todayphotobiological
From photo- + biological.
Etymology from Wiktionary, CC BY-SA 4.0.