    Sentence & Who was Chai  Subcommittee on Oversight and  Investigations?         Sentence 2: On June 2005, Rep. Joe  Barton, chairman of the House Committee on  Energy and Commerce wrote joint letters  with €d Whitfield, Chairman of the  Subcommittee on Oversight —_ and  Investigations demanding full records on  climate research, as well as personal  information about their finances and  careers, from Mann, Bradley and Hughes.