Fisherian runaway: Difference between revisions

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There are many animals with exaggerated ornament, e.g. peacock tail<ref>https://link.springer.com/chapter/10.1007/978-3-319-46233-2_17</ref> and narwhal tusks.<ref>https://royalsocietypublishing.org/doi/10.1098/rsbl.2019.0950</ref> Some animal species have been theorized to have gone extinct in part due to runaway selection.  A prominent example is the Irish elk.  Female Irish elk may have selected male elk with increasingly larger antlers.  Some recovered antlers measure 9 ft (2.7 m) across and weigh over 90 pounds (40 kg). The extreme nutritious cost to grow such huge antlers, coupled with the burden of such a heavy load, were possibly more than the males could handle, particularly as their food source density decreased during environmental changes.<ref>The evolution of sexual strategy in modern humans: an interdisciplinary approach by Collins, Kendra Marie, https://studyres.com/doc/2550939/--california-state-university</ref> Natural selection would have favored males with smaller bodies and antlers for their lower nutritional needs and superior mobility, however the sexual selection pressures were strong and the ornament has become so fixed in a positive feedback loop, that it may have ultimately caused extinction.<ref name="moen1999" />