It's all about getting your genes in the next generation.
你只想把自己的基因传给下一代。
Evolution tends to favor types of displays between members of the same species that are not necessarily lethal,
进化常常偏爱相同物种中成员间的各种形态的表现形式，那未必会是致命的，
that it becomes clear that the one who wins that match has something better than the other one...
那很清楚地表明在战斗中获胜的一方一定是在某方面强于对手更健康的外形，
a healthier pattern, a more vigorous display, hinting at a better internal condition, a more healthy condition.
更具活力的表现，都暗示着其内部状况更优秀也更健康。
One of those things that seem to be ture in the animal kingdom of the day is that when animals have extreme structures,
在动物王国里，有一条颠扑不破的真理说的是，当动物拥有终极构造时，
they do use them as a display-board and advertising-board, especially during the breeding season.
它们一定会拿来当做自己的"标签"和"宣传板"，在繁殖季节尤为突出。
Weighing in at six tons, Triceratops are the street fighters of the Cretaceous.
体重达六吨的三角龙是白垩纪时期的街头斗士。
For this brute, the most powerful herbivore of all time, evolution means getting stronger, tougher and meaner.
对这种野兽来说，作为史上最强大的食草动物，进化就意味着变得更强壮，更坚韧，还有更凶恶。
And those are exactly the traits females look for in males.
而这些特性正是雌性恐龙所看重的。
Triceratops' bony frill forms a defensive shield.
三角龙的骨质褶边形成了一块防御盾牌。
A strong one is a sign of strength and power.
强壮的盾牌就是力量和能力的象征。
But maybe it advertises something else as well.
但也许这也能展现其他东西。
The frill might have evolved as a defensive measure against predators.
这些褶边已进化成了一项能够抵御食肉动物的防御措施。
It might have evolved as a species-recognition character.
那也许是一种属于这个物种独有的特征。
But there's no reason why it couldn't have been taken advantage of in the evolutionary process as a sexual billboard.
但它们也有充分的理由在进化的过程中把这当成一块"求偶广告牌"。
So a Triceratops' frill could, like a peacock's feathers, be a display of virility?
那么三角龙的褶边能像孔雀的尾羽一样成为一种炫耀的资本吗？
One clue is that it changes color.
线索之一就是它会变色。
The bone that forms this shield is riddled with a meshwork of arteries and veins.
形成盾牌的骨头上布满了纵横交错的动脉和静脉。
In times of stress or excitement, hormones are released into the bloodstream.
在紧张或兴奋的情况下荷尔蒙就会被释放到血液中。
Arteries in the neck widen, and blood rushes to the frill, turning it blood red.
此时颈动脉就会扩张，血液会直冲褶边把它变成了血红色。
It's a ritualized drama with one single goal.
这种仪式化的戏剧性变化其目的只有一个。
They're gonna have to demonstrate to the females that they're the biggest and healthiest and perhaps smartest of the males,
它们想向雌性恐龙证明自己是最强壮的，最健康的，也许还是最聪明的，
that they have earned the right to reproduce by proving themselves worthy.
雄性恐龙它们要证明自己配得上获得繁殖的权利。
