Amongst mammals, human females actual limited fertility is the odd thing.

Visual and maybe hormonal attractiveness may change over time with other mammals too, but not actual numeric quantity of eggs. (I'm not sure if there is broad enough data on egg viability across all mammals though, but the fixed quantity and therefore approximate time period of fertility is more easily seen)

Given that this variable is the different one, the differences in human populations (ie. the competition for being chosen) really should be evaluated with this aspect weighted more heavily.