R
rossum
Guest
No. Back then they were single celled eukaryotes, and single celled organisms do not have external genitalia. Rather than one individual splitting into two genetically identical individuals by asexual reproduction, they evolved a way for two individuals to mix their genes, resulting in offspring with a mix of genes from both parents. Basically an extension of the already existing horizontal gene transfer, but slightly more organised. External genitalia evolved about 500 million years ago in the late Precambrian and Cambrian, about 700 million years after sexual reproduction evolved.So, they must have spontaneously evolved male and female genitalia exactly at the same time.
All these question you ask can be answered by a little research on the Internet.
rossum