This episode is about horny animals!
Also like peacocks and stuff.
Hey domesticated wildlife, Trace here for Dnews!
With Christmas around the corner, it's time to take a look at one of the most famous mythical
creatures in Christmas lore: no, not Yukon Cornelius.
Rudolph the red-nosed reindeer.
Although it's not Rudolph's nose we're thinking about, but Rudolph's antlers.
Reindeer shed their antlers every year.
They're thought to do this because at a certain size, the antlers become too cumbersome
to deal with.
Sure, they're useful for defense sometimes, but antlers also slow them down, making them
more susceptible to being attacked, and keeping them from running away.
And it's not just reindeer, and it's not just antlers.
Plenty of animals have characteristics that directly threaten their survival.
Peacocks are another example; their enormous bright plumage is basically a giant, "Hey,
here I am!
Eat me!" for animals like wild dogs, raccoons, and even tigers!
According to various theories of natural selection, that kind of trait -- called ornamentation
-- should be pretty quickly wiped out; if you're a peacock that doesn't show off,
you're less likely to be eaten by a predator, and more likely to procreate, thus passing
along your lack of plumage.
Even dung beetles have excessively sized horns on their heads that work logically anyway
against their survival.
But despite going against natural selection, this ornamentation actually favors something
called "sexual selection".
These bright and flashy, or large and antler-y, extras are thought to help males of the species
stand out and attract females.
And that's pretty interesting, because if females prefer mates with ornamentation, then
their offspring will likely also have both ornamentation and a preference for it among
females, in an ongoing sort of " feedback loop".
This is called "Fisherian runaway" or "runaway selection", where the female's
preference for a specific trait -- in this case, ornamentation -- is strong enough that
it propagates itself through subsequent generations, leading to a "runaway" of that particular
trait.
This theory helps explain why a trait that seems detrimental would stick around, when
natural selection would seemingly phase it out..
But why would females prefer a mate that might be more likely to be killed?
One theory, called "handicap principle," suggests that if your ornamentation doesn't
get you killed by the time you're sexually mature, then you're probably a strong member
of the species.
For example, if you survive into adulthood with your antlers intact, it shows you're
more fit than those deer with antlers who couldn't run fast enough to escape death.
But that's still kind of a recipe for disaster.
What if your species doesn't have a lot of mates to choose from, and ALL the ornamented
males are killed, just because there was an evolutionary imperative to show off?
Now you're extinct
Well, researchers from Northwestern University found that many "ornamental" animals actually
end up splitting into two distinct subspecies on the basis of how likely they are to survive
with their ornaments.
Basically, in order to resolve the conflict of sexual selection versus natural selection,
animals simply evolved in both directions.
Some subspecies follow this sexual model, and have crazy big antlers or feathers or
horns, which are used to prove their fitness to potential mates.
Others develop tiny antlers, feathers, and horns, and simply live long enough to procreate.
And what's fascinating, is that there's almost nothing in between.
There are very few species with medium sized ornaments.
So to bring all this back to Rudolph.
Unlike most species of deer, both male and female reindeer grow antlers, and shed them
every year.
But males usually shed them around wintertime, whereas females shed around the summer, give
or take a few months for both.
So if Rudolph had antlers around December 25th, then it's most likely, Rudolph…
was a lady.
Keep that in mind while watching the TV special, change your perspective.
So now you know some fun facts about reindeer, how much do you really know about mistletoe?
Check out this video of seven things you probably didn't know about it.
What do you guys think?
Do you have any other Christmas myths you want us to bust?
Let us know down in the comments, make sure subscribe and we'll see you next time.
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