It's inaccurate to call that "the golden ratio" when it's not. If a plant has a logarithmic spiral with a factor of 1.4-1.8 then you shouldn't call it the same as a spiral of (1+sqrt(5))/2, for a lot of reasons - first, there's too much variance; second, there's no way to really prove whether it's the golden ratio or some other number. Suppose there is a slightly different number, say, (2+sqrt(8))/3, which is similar (~1.6 and ~1.6) yet entirely different - is it not just as possible that this is the magic number of life rather than the golden ratio?