> 'Aliens' visiting Earth would immediately categorize us into groups very crudely resembling the groupings we use today I wonder about that... I can't tell th

> 'Aliens' visiting Earth would immediately categorize us into groups very crudely resembling the groupings we use today I wonder about that... I can't tell the difference between, say, a male octopus and a female octopus, but octopi can. Maybe the differences that seem so obvious to us are actually almost imperceptible outside of our species.