"People, like all mammals, are female unless masculinised.
 Female is the `default sex' (it is the other way round in birds).

 A single gene, called SRY, on the Y chromosome starts a cascade
 of events in the developing foetus that leads to development of
 masculine appearance and behaviour"

 [p. 160]
 - Matt Ridley's "Nature Via Nurture" 2003 ISBN 1-84115-745-7

------------------------------------------------
  Evidence file for 

  Altruist Survivor's "Options" page
  http://www.perceptions.couk.com/genes8.html

  and "Sexual Differences" page
  http://www.perceptions.couk.com/genes4.html
 
------------------------------------------------

              FURTHER REFERENCES

  GO - "search perceptions" - in SEARCH-ENGINE


file-ID www.perceptions.couk.com/template.txt