One example of allometry ("other" -
"measurement") is the positive allometry shown by
antlers (including those of the extinct Irish
elk) and by horn-like structures generally. The
larger the animal the disproportionately larger their
antlers. Thus, if two deer are different sizes, one twice
the size of the other, the larger one's antlers are more
than twice as big.
This allometric relationship holds both
intraspecifically (between members of the same species) and
interspecifically.
The size of horn like structures is often
said, wholly incorrectly in Sporus's view, to be due to sexual selection.