Thom and the other debutants, 22-year-old centre Ben Cairns and lock Matt Mustchin, 31, will take their place alongside a man at the other end of the experience scale, Chris Paterson, who will equal Scott Murray's cap record total as he makes his 87th Test match appearance.
Scotland head coach Frank Hadden said: "I've been discussing this selection on and off for the best part of two months with Sean Lineen, Andy Robinson and Alan Tait.
"Once it became clear who was available and who was unavailable we looked at how we were going to have to play and we're confident we have picked a side to do what we need to do in such an important game this weekend."
On his new caps, Hadden said: "I've been tracking Ben Cairns since he was 17 as he looked like a future outside centre. He is very mature both on and off the field and has the ability to play his role so it brings out the best of those around about him.
"I spoke to Thom before the World Cup and told him that his whole season should be geared to getting on the plane to Argentina. He thoroughly deserves this opportunity as he's a very exciting talent.
"Matt is abrasive and combative, the sort of qualities that will be ideally suited to the forward battle with the Pumas this weekend."
Johnnie Beattie, 22, whose last Scotland appearance was in the 2007 RBS 6 Nations Championship against France, returns to win his fourth cap at No 8, reward from Hadden's perspective for the "greater consistency he has shown this year."
Paterson, whose 100% goal kicking record has stretched to his last 33 strikes, was typically modest in assessing his achievement. "You have to be proud of what you have achieved but the moment to start dwelling on it is sometime in the future.
"Records are not the finishing line. What I aim for on Saturday is to produce a performance where I have as a big an impact as possible in helping Scotland to win."
Hadden added: "Sometimes, in the pursuit of winning matches, coaches gloss over this kind of milestone but everyone has to acknowledge the significance of this landmark and one that Chris richly deserves."
Scotland team (team sponsor Murray) to play Argentina in the first Test at Gigante de Arroyito in Rosario on Saturday 7 June (kick-off 4.10pm BST)
Scotland 1st XV
15 Chris Paterson (Edinburgh)
14 Simon Danielli (Ulster)
13 Ben Cairns (Edinburgh)
12 Graeme Morrison (Glasgow Warriors)
11 Thom Evans (Glasgow Warriors)
10 Dan Parks (Glasgow Warriors)
9 Mike Blair (Edinburgh) CAPTAIN
1 Allan Jacobsen (Edinburgh)
2 Ross Ford (Edinburgh)
3 Euan Murray (Northampton Saints)
4 Matt Mustchin (Edinburgh)
5 Scott MacLeod (Llanelli Scarlets)
6 Alasdair Strokosch (Gloucester)
8 John Beattie (Glasgow Warriors)
7 Allister Hogg (Edinburgh)
Substitutes
16 Dougie Hall (Glasgow Warriors)
17 Alasdair Dickinson (Gloucester)
18 Alastair Kellock (Glasgow Warriors)
19 Kelly Brown (Glasgow Warriors)
20 Rory Lawson (Gloucester)
21 Phil Godman (Edinburgh)
22 Simon Webster (Edinburgh)
Referee: Alan Lewis (Ireland). Touch-judges: Alain Rolland (Ireland) and Cobus Wessels (South Africa). TMO: Shaun Veldsman (South Africa)