Interim head coach Stuart Lancaster has chosen Northampton's Dowson ahead of Ben Morgan at No8, although the Scarlets star is in line to win his first cap from the replacements' bench.
Saracens duo Barritt and Farrrell will continue their club partnership in midfield, with team-mate Charlie Hodgson given the reigns at fly-half as a result of Toby Flood's injury-enforced absence.
Fellow Sarries regulars David Strettle and Mouritz Botha will also start in Edinburgh as Lancaster makes a total of nine changes from England's last outing in the World Cup quarter-final defeat to France.
Strettle hasn't started for his country since 2008, while South African-born Botha will win just his second cap in the second row.
Alex Corbisiero, Dylan Hartley and Dan Cole start in the front row, with Stade Francais lock Tom Palmer joining Botha at lock and new captain Chris Robshaw selected at openside.
Leicesterblindside Tom Croft joins Hodgson as the only Lions in the starting side and his clubmate Ben Youngs wears the No9 shirt.
Ben Foden and Chris Ashton complete the line up at full back and right wing respectively, while Wasps hooker Rob Webber, Leicester lock Geoff Parling, Northamton scrum-half Lee Dickson and Harlequins centre Jordan Turner-Hall could join Morgan in making their debuts from the bench.
England (v Scotland, Murrayfield, Saturday, 5pm)
Ben Foden; Chris Ashton; Brad Barritt, Owen Farrell, David Strettle; Charlie Hodgson; Ben Youngs; Alex Corbisiero, Dylan Hartley, Dan Cole; Mouritz Botha, Tom Palmer; Tom Croft, Chris Robshaw (captain), Phil Dowson
Replacements: Rob Webber, Matt Stevens, Geoff Parling, Ben Morgan, Lee Dickson, Jordan Turner-Hall, Mike Brown
NB Bold denotes Lion