They most likely married unnamed sisters, as did the 12 sons of Yaacov
according to some commentators. The mishna in Sanhedrin goes unchallenged
when it takes as a fact that Hashem created all mankind (male and female)
from ONE person. I believe the best scientific evidence supports this, DNA
testing etc., based on the probability of a recent complex creation and/or
the Torah 5757 time line to be true.