Note: this proposal parallels the creation of Man with their naming . “in the day” links to Gen 2:4, “God created man” comes from to Gen 1:27, “In the likeness of God” is from Gen 1:26 and parallel with “blessed them” from Gen 1:28, “male and female” comes from Gen 1:27. The central point about Man being both male and female is emphasised in the genealogy that follows –  “sons and daughters” occurs for each generation. 

1 This is the book of the generations of Adam.

A. In the day that God created (Gen 2:4)

B. man (Adam),

C. in the likeness of God made he him (Gen 1:26);

D. 2 Male and female created he them (Gen 1:27);

C’. and blessed them (Gen 1:28),

B’. and called their name Adam,

A’. in the day when they were created (Gen 2:4).