I remember reading somewhere that the Irish Elk went extinct because their antlers simply became to big. Is there any truth to this? Are there any cases of a trait becoming bred to this extent?
It is a widely-known factoid. Don’t know how much truth there is to it, but they became extinct at the end of the last Ice Age–when a whoooole lot of other critters were also becoming extinct. It was apparently a very stressful time.
I think the term for what you’re talking about, Harborwolf, is “pathologic allometry” – a trend that becomes counterproductive when carried too far.
It’s my understanding that it’s been abandoned by most evolutionary biologists, and probably been refuted insofar as such theories can be refuted.
Their particular adaptations, antlers and all, were specialized for a particular ecological condition, and they could not adapt or migrate fast enough when things changed at the end of the Wisconsin/Wurm glacial stage to survive. (E.g., suppose them to have been creatures of tundra and the open forest of the taiga in Ice Age Europe, which I think is accurate – and notice that the North and Baltic Seas prevent them migrating north as those two zones did.)
It sounds more like orthogenesis, actually (can’t say I’ve ever heard the phrase “pathological allometry” before) - the changing of organisms along pre-disposed lines. Thus, once the antlers of the ancestors of the Irish elk (Megaloceros - more properly a “giant deer”, as it is neither exclusively Irish, nor an elk) started getting bigger, they could only continue to get bigger, even if they eventually became a liability.
Correct. The now-standard line is that Megaloceros is thought to have gone extinct as a result of changing climate at the end of the last ice age. It is now believed that they may have hung on as relict populations for a short time thereafter, however.
For something like the Irish Elk… what were the purpose of the enormous antlers?
Intimidating rivals then whacking hell out of those who don’t get the message? I think I saw the skull and antlers of one in Kilkenny Castle, either that or a bigass dear 