Rating: 2.5 stars

Sweet, strange and at times slightly scary, the Ice Age fable “Alpha” tells the origin story of man’s best friend. You could call it “Dog Zero,” for the way it portrays the first wild wolf to let down its guard with a human, some 20,000 years ago, and form the first tentative bond that every modern lover of a “fur baby” knows.

But calling it “Alpha” will also do the trick.

That simple, almost primitive moniker does triple duty here: as the status of the film’s canine subject in its pack; as the nickname the animal is given by the film’s hunter-gatherer who adopts him, Keda (Kodi Smit-McPhee); and as Keda’s unfamiliar dominant role in the interspecies dynamic that becomes the film’s true subject.

The story by director Albert Hughes and screenwriter Daniele Sebastian Wiedenhaupt — elegantly told with minimal dialogue, in an invented early- ­European language — first centers on Keda, the gentle son of a tribal chieftain (Johannes Haukur Johannesson) who doesn’t have his father’s stomach for killing. Keda “leads with his heart, not with his spear,” explains Mom (Natassia Malthe), before the film’s opening hunt, which sees Keda gravely injured and left for dead after he is thrown off a cliff by a bison.

That’s one of the scary parts.

This family-friendly film is something of a departure for the filmmaker (one half of the Hughes Brothers, along with his sibling Allen, a filmmaking duo known for such violent fare as “The Book of Eli” and “From Hell”). And yet there are moments of intensity. Another one is the scene in which Alpha’s pack attacks Keda, who stabs the animal in self-defense. When Keda decides to nurse his victim back to health rather than put it out of its misery, a symbiotic relationship develops.

That’s the scientific way of putting it. Others would call it love.

Kodi Smit-McPhee, right, plays an young Ice Age man who befriends a wolf in “Alpha.” (Sony Pictures Entertainment)

Make no mistake: “Alpha” is not paleoanthropology. Although largely accurate in its depiction of the roots of canine domestication in a hunting context, it is not above corniness. After Alpha has healed and Keda is trying to shoo the animal back to its pack, Keda tosses a stick to scare it away, which Alpha promptly retrieves, in a proto-version of fetch.

It’s a bit cheesy, but so what?

The film’s plusses include jaw-dropping cinematography of lunar-looking landscapes, filmed in rural Canada and Iceland. (Invest in an Imax 3-D ticket; it’s worth it.) Smit-McPhee is also quite affecting, in a performance that calls for very little speaking, and a screen partner that is, well, known for chewing the scenery. The actor’s canine counterpart (Chuck, a Czechoslovakian wolfdog) will likely induce several awws, if not outright tears, in several interactions that show the intensity of their deepening connection.

I guess they don’t call August the “Dog Days” for nothing. “Alpha” is sort of a prequel to the canine-centric rom-com of that title that came out earlier this month. It explains, in the manner of fact-based fairy tale — with a little bit of hooey and just enough history — how a boy and a dog went from snarling at each other to curling up on the couch together.

PG-13. At area theaters. Contains some blood and intense peril. In an invented language with subtitles. 96 minutes.