and daughters were born to them (bereishis 6:1)

Question

There is a strange way of saying that the human population increase on parsha Bereishis (6:1). The pasuk says:

וַֽיְהִי֙ כִּֽי־הֵחֵ֣ל הָֽאָדָ֔ם לָרֹ֖ב עַל־פְּנֵ֣י הָֽאֲדָמָ֑ה וּבָנ֖וֹת יֻלְּד֥וּ לָהֶֽם:

"And it came to pass when man commenced to multiply upon the face of the earth, and daughters were born to them".

These last words are intriguing. Does that implies that until that time the daughters were not born to them? The Radak makes an interesting point here by saying that it is obvious to think that human species cannot survived without male and female, but he does not explain why the pasuk miss to mention the male offspring.

Abravanel to Noach (p. 214) (and others) says that these words meant a lot of daughters (as opposed to a few ones) but this not explain why the males are absent here too. (In fact, he does say that both male and female are hinted in "Adam" in the begining of the pasuk, but then the mention of daughters would be superfluous).

Interestingly, there is no explicit mention of female children being before this (with the exception of Cain knowing his wife). It almost makes one want to presume that there was some kind of asexual reproduction for a while. The causative הוליד is not used until Terach; before that it’s only the simple ילד or יולד , almost implying as if the males had their kids by themselves (?). Is there any commentary or midrash on that?

Answer 1

The Netziv seems to indicate that it is stated this way, because it was a prelude to polygamy and rapid population expansion:

ובנות ילדו להם. בא הכתוב ליישב שלא יהי׳ מוקשה היאך אפשר שישא אדם א׳ הרבה נשים והרי א״כ תחסרנה נשים לכמה אנשים. מש״ה פי׳ הכתוב שרצון ההשגחה העליונה הי׳ בזה. מש״ה יולדו בנות הרבה יותר מבנים. באופן שהי׳ אפשר לכל זכר ליקח נשים הרבה

This pasuk is coming to teach us how could one person marry multiple wives- wouldn't this mean that other men wouldn't have any women to marry? Therefore the pasuk tells us that there were many more women born than men and this was "hashgacha elyona" and that every man could marry many women [ie that the world should be populated]

The Malbim adds:

ויהי. כבר הזכירו חכמי הטבע כי במדינות שאין נושאין רק אשה אחת יולדו זכרים ונקבות בשוה, ובמדינות שנושאים נשים רבות יולדו נקבות כפל מהזכרים.

In places of monogamy, an equal number of men and women are born. However in places where polygamy is the rule, many more girls (lit. "double") are born than boys.