text: 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
target: 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.