This entry examines Surah an-Najm 53:45-46, which ties the making of 'the two mates, the male and female' to the emitted drop, and its relation to the chromosomal mechanism of sex determination discovered in the twentieth century.
The source text
وَأَنَّهُۥ خَلَقَ ٱلزَّوْجَيْنِ ٱلذَّكَرَ وَٱلْأُنثَىٰ
“And that He creates the two mates - the male and female -”
Qur'an 53:45 · Saheeh International
مِن نُّطْفَةٍ إِذَا تُمْنَىٰ
“From a sperm-drop when it is emitted.”
Qur'an 53:46 · Saheeh International
“Thawban reported: A Jew asked the Prophet... 'From what is man created?' He said: 'From the fluid of the man and the fluid of the woman... The reproductive substance of man is white and that of woman is yellow, and when they have intercourse and the male's substance prevails over the female's substance, it is the male child that is created by Allah's permission, and when the substance of the woman prevails over that of the man, a female child is formed.'”
Sahih Muslim 315 · Grading: sahih (Bukhari-Muslim by definition)
What was understood in the seventh century
In the seventh century it was widely believed that the mother determined the sex of the child, or that sex followed from such factors as which side of the womb the seed settled in, the relative heat of the partners, or the direction of the wind at conception. No account located sex determination specifically in the male contribution, and there was no mechanism by which it could have been placed there.
The verse pairs the creation of 'the two mates, the male and female' with 'a sperm-drop when it is emitted,' so that the making of both sexes is attached to the emitted drop. A supporting narration in Sahih Muslim (no. 315) treats the outcome as a contest in which the male's or the female's 'substance' prevails, the reproductive substance of the man being described as white and that of the woman as yellow. This framing is closer to the older two-seed theories than to a chromosomal one, and it complicates any simple appeal to the verse.
The modern correspondence
Genetics established the modern mechanism in the twentieth century. The XY system was described by Nettie Stevens and E.B. Wilson in 1905, working independently on insects: the sperm carries either an X or a Y chromosome and so fixes the sex of the offspring, while the ovum always contributes an X. The male gamete is therefore the deciding factor, and the female gamete is uniform in this respect.
Commentators read the verse's association of the two sexes with the male's emitted drop as consistent with this finding, since it is the male contribution that determines whether a male or female results. The correspondence argued here is between the verse's linkage of sex to the drop and the later discovery that the sperm carries the deciding chromosome. Supporters emphasize the shift this represents from the prevailing seventh-century view, which placed the determination of sex with the mother or with external circumstances, to an account that attaches it to the male contribution, in the direction the modern mechanism confirms. The Britannica entry on sex determination, cited below, sets out the XY system on which the reading relies.
Considerations and counterpoints
Critics argue that 53:45-46 only says male and female are made from the drop, without asserting that the sperm alone sets the sex, so reading in the XY mechanism is generous to the text. They also point to the accompanying hadith, whose language of the man's fluid 'prevailing' over the woman's echoes Hippocratic-Galenic two-seed theory and misdescribes the mechanism, since the female gamete does not compete to determine sex. The presence of that hadith in the same tradition, they contend, tells against reading the verse as an anticipation of chromosomal genetics. They further observe that the verse's plain concern is the pairing of the sexes as evidence of design, a theme it shares with many creation passages, rather than any statement about which parent's contribution is decisive.
Credibility rating: Tier 2 · Interpretive — The Qur'anic verse plausibly ties sex to the male drop, but the supporting hadith frames determination as a contest between male and female 'fluids,' which does not match the chromosomal mechanism.