Tristan: I've just read this interesting article about babies
Gavin: hahah, why interesting?
Tristan: Did you know that every year there are more male than female babies born?
Shane: Sure, it's normal, a phenomenon known for centuries
Tristan: really? I haven't known
Tristan: so what is the reason for that?
Shane: It's hard to say, there are different theories
Shane: what does the article say?
Tristan: that the main theory is evolutionary
Shane: right
Tristan: that boys and men generally die more often, so the nature regulates it to keep a balance between adult male and female
Shane: true, but some other scientists say it's about sperm
Tristan: sperm?
Shane: yes, that female sperms (with chromosome X) are robuster 
Shane: but one doesn't exclude the other
Tristan: It's fascinating
Gavin: You're such a nerd really
Tristan: hahah, a bit
Shane: Gavin, we all are nerds :P you're just a technology nerd and an ignorant in every other field
Gavin: I'm afraid it may be true
Tristan found out from an article that each year there are more male than female children born which is linked to an evolutionary theory. Shane alleges an alternative theory linked to female sperms.