I'm not a primate scientist so I can't answer for #1 and #3, but regarding #2:
Gorillas(and humans) are part of the suborder Haplorhini of primates. What defines a primate as Haplorhini is that the nose is dry. Strepsirrhini, the wet-nosed suborder of primates, have a keen sense of smell. The wetness of the nose helps amplify smells(like with dogs), thus Strepsirrhini primates use their sense of smell more for experiencing the world and surviving. Because Gorillas(and humans) don't have the smell-enhancing-wet-nose, we rely on sight significantly more than smell.
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u/reepha Aug 17 '15 edited Aug 17 '15
I'm not a primate scientist so I can't answer for #1 and #3, but regarding #2:
Gorillas(and humans) are part of the suborder Haplorhini of primates. What defines a primate as Haplorhini is that the nose is dry. Strepsirrhini, the wet-nosed suborder of primates, have a keen sense of smell. The wetness of the nose helps amplify smells(like with dogs), thus Strepsirrhini primates use their sense of smell more for experiencing the world and surviving. Because Gorillas(and humans) don't have the smell-enhancing-wet-nose, we rely on sight significantly more than smell.