protocell

In fact, our current understanding of prebiotic evolution makes it evident that the
membrane-bounded vesicles that evolved into the protocells could form only because of
the existence of amphiphilic molecules, which in turn required that water molecules exhibit
an electric polarity (their electrons staying closer to the oxygen atom than to the hydrogen
atoms, so that they would leave an effective positive charge on the latter and a negative
10.2 Contingency vs. determinism in the origin of life 219
charge on the former). Without this subtle electric property of water, the formation of
vesicles, and thus the emergence of life as we know it, would not have been possible. In
some sense, then, the possibility of life in the universe was implicit from the formation of
water and, indeed, from the very formation of the elements hydrogen and oxygen shortly
after the big bang.