Mageth

I fail to see how that statement can be interpreted to be claiming that "head butting caused antlers to form on deer's heads."

Where on this thread has anyone claimed that "head butting caused antlers to form"???

kingzfan2000

Okay, so no one thinks that shoving heads caused antlers to form. Now that we have that settled, is someone going to say what did cause the origin of antlers?

kingzfan2000

Im a creationist so obviously I think all creatures were designed and if no one can give me a reasonable explanation for why and how antlers started sprouting from some creatures head, then I see no reason to think otherwise. However, I cannot prove that they were designed anymore than you can prove that they were not but imo, the evidence supports design. The evidence is that deer have antlers, use them for a specific purpose, and no one has presented a reasonable idea for what would cause symmetrical bony structures to just randomly protrude from a creatures head, and why antlers would proceed to grow from these structures. Im sorry if thats not sufficient evidence for you. It really seems that design is the only logical answer but thats simply unacceptable to an evolutionist and I completely understand that. Bottom line, if you or anyone else has evidence or an idea for how deers antlers originated, then simply present it.

judanne

Evidence? Better yet, a story! Everyone likes a good story don't they? Well actually, two stories. The first is just a short one. I had a bump develop on my head a while ago but had it removed. Thankfully it was just a cyst and not horns or antlers, so don't worry kingzfan :devil3:

Second story:

A group of cervids ascended to the top of Bald Mountain early one spring in anticipation of that year's mating season. All the bucks had a lively spring in their step since this was by far their favorite time of year. There was a lot of masculine prancing, snorting and head swinging, practice for the exciting rituals of the coming days. The largest bucks maintained a front line position, strutting their stuff as the timid does looked on in admiration.

One smallish buck trailed behind, hoping that his proximity to the does would get him noticed, but not so much noticed that the unsightly bumps on the front of his skull would be obvious to all. A freak - an accident of genetic mutation - not like his brothers, not like the other bucks who would be sure to have first choice in mounting the fairest and sturdiest does. He was eyeing a spindly-legged, frail looking doe with untoward whitish spots on her back. Little buck witnessed last years rut but this would be the first he would participate in. He thought to himself, inasmuch as a cervid could think, when the great challenges begin, I'll just hang back. Don't want to get my head bashed in by one of those big bucko's, that's for sure. Maybe nobody else will want that funny looking little doe... Little buck felt a twinge of excitement at that thought, as sex chemicals began to race through his bloodstream. Another cervid thought flashed through his cranium, hmm...well maybe it won't hurt too badly. I think I can, I think I can, I think I can...

Later that afternoon, things were heating up in the forest. The prancing, snorting and head swinging became more vigorous and aggressive. The big bucks were keeping one eye on their opponents and the other on the sturdiest, well seasoned does. Little buck never really understood what possessed him that fateful day, but following the first challenge and subsequent quadrapedal dance of the victor, little buck lowered his head and beat his cloven hoof against the ground. The sturdiest and finest doe looked up from the patch of lichen she had been delicately nibbling to watch this unseemly challenger prepare to charge. She had assumed the big buck would become her mate. Who is that randy little upstart, she thought. The big buck snorted and rolled his eyes. Confidently lowering his head, he prepared to meet this arrogant youngster in battle. They charged, skulls making a hollow thud upon contact.

Big buck: oh crap! my head. You little tick-ridden cur! What did you do to my head? Oh, that hurt. What the...what are those things on your head? Oh cervid! I'm gonna have a headache for a week. Ok, ok, you can have sturdy doe-eyes over there. I had her last year anyway. Just don't bash me with those horrid bumps again, sheesh! Big buck backs away, eyes already wandering toward a younger doe, attractive but still an unproven breeder.

Little buck couldn't believe his luck. Maybe those ruddy bumps aren't such a bad thing at all, he thought. He soon noticed that sturdy doe was looking expectantly in his direction. Another rush of sex chemicals. He approached sturdy doe with a twinkle in his eye and head held high. They nudged and nuzzled and sniffed each other. Awkwardly (it was his first time, after all) little buck mounted sturdy doe, entered her and began to thrust. He slipped off once, but remounted and continued at a feverish pace until #$@#$@!!Oh wow! Life is goooood! I think I need to sleep now.(OK, I couldn't resist that little bit of anthropomorphism

The mountain-top cervid festivities were memorable (well, at least for a few moments after it was all over and everyone went their separate ways). Little buck straggled along after sturdy doe for a little while but all she seemed interested in was eating lichen and tender bark. Eventually little buck veered off in a different direction and would not see sturdy doe until the following spring, when she and her three bumpy-headed little bucks made their way to the mountain top once again.

Time passed and as little bucks glory days began to wane, his many bumpy-headed offspring proved as successful and brazen as was their father. Many generations later, most of the deer on Bald Mountain had bumps on their heads. Some larger and some smaller than others. In general, rutting season was one big headache, but if you were a buck who had bigger bumps than the others, chances are you'd end up with the best doe-babe, a good sturdy breeder, a good mother. Your offspring would not only survive, but the big bumps you passed on to them would help them win the choice does of their generation, and those of many generations to come.

The end.

Fact, fiction. Who cares, right?

Berthold

Okay, so whenever you observe movement in a context that is not free of friction, you discard Newtonian physics in favor of Aristotelian.

This is an analogy, and only indirectly linked to the topic.

Oolon Colluphid

I’ll add another idea to Judanne’s tale, following from here (anthropomorphised so kingsfan can follow the idea):
... and the older females -- including the mother who fancied their father in the first place -- noticed. "Those bumpy-headed youngsters turned out alright", they told their daughters. "You could do worse than one of them."

So the young does chose the bumpy-heads. Not only were they more brazen, more willing to put their skulls where their mouths were, so to speak... but having the bumps were a sign of this. An easy way for a female to spot a good father.

A few generations later, the females knew to look for bumps. (In fact, it was simply that those who chose the bumpy males left more descendants.) But if looking for a bumpy head, bigger bumps are literally more prominent. They made their owners stand out from the crowd. So bigger bumps were more often selected by the females. Soon, every male who wanted to mate had to have the New Improved Head Bumps to stand a chance at all.

But then there was a quandary. These bumps cost money. The currency was calcium, which isn’t that available to a vegetarian. A buck that could get away with not growing these bumps could perhaps be healthier, not having to divert precious resources to growing the bumps. But not only could he not challenge the males without an even worse headache than that first un-bumpy male; he would not be what the females were looking for, in a quite specific way: not having those desirable bumps. So even though the bumps were expensive, the males were stuck with growing them.

A few generations later. Now, only the healthiest males have the largest, most desirable and conspicuous bumps, because the less healthy ones cannot afford to grow them so well. These bumps are even more of a signal to females, advertising the fact that I’m a big strong male, I can butt the brains out of any weedy bucks that dare challenge me! And the females that choose the bumpy-heads do so because their mothers, grandmothers and great-grandmothers chose them. Any genes involved in their brain wiring that made ‘having a bumpy head’ desirable spread through the population as the generations pass, just as surely as having the bumps made a buck desirable.

This population is now stuck in a positive feedback loop. If you’ve got big bumps on your skull, the females fancy you; and fancying a bumpy-headed buck is a good way of picking a healthy father for your fawns... who will inherit the brain wiring for realising that good male = bumpy head. But as ‘having bumps’ is a stimulus to the does, ‘having bigger bumps’ is even more of a stimulus, making any buck with them even sexier. Again, since only the healthiest males can afford to ‘make them big’, a female choosing even bigger bumps is picking the best fathers... and passing on whatever made her desire big bumps to her daughters... while the male passes on the genes for making big antlers.
Please, kingsfan old chap. Please explain your fixation on finding something we cannot explain. Have you heard of the 'god-of-the-gaps' argument? Have you not heard why it is such a poor argument?

Suppose we did not have a clue about antler origins, and could not even speculate as Judanne and I have above. What difference would it make? In science, we work with the evidence we already have, and try to gather more. Of course there are gaps. But plugging Goddidit into a gap is no real answer, and can make you look pretty dumb when a better evinced explanation does come along! “He threw himself to the ground and writhed around, arms flailing. The demons did it!�? looks rather daft now we know about epilepsy, don’t you think?
But you see, we can reject design, even without considering whether -- or not -- evolution can explain antlers. See here for why. You see, antlers are a poor design.

Some ways in which antlers are a poor design.

• They grow, only to be shed each year. Seems like a waste of materials, no?

• Since antlers are built from calcium, and since deer eat green vegetation, a large source of calcium is needed. Deer get much of this calcium by depleting their own bones -- mostly the ribs. Is that a good idea?

• The remainder of the calcium come from their food. In order to grow their huge racks of antlers, deer and elk must eat more than 50kg of calcium each season. That’s an awful lot of extra calcium for a vegetarian to find... and for what purpose?

• Antlers start as bony growths covered with skin and hair, called velvet. When the antlers reach their full size, the blood vessels close down, and the velvet dries up and peels off. The deer assists this process by rubbing against trees, and to mitigate the waste of energy that went into growing the velvet, as it peels away, they eat the newly removed skin. But the question to the designer is, why grow the velvet in the first place? Velvet: grow it, let it die, use more energy to rub it off, and recycle the remains... or not bother to grow. The better design would be...? You decide.

Why not just small antlers? They’d still be a sign of health to the females, and would still be useful for contests. Small antlers would be lighter to carry around the rest of the year, so would not need to be so wastefully shed.

Oh, and if we talk about deer in general, there's a whole load more poor designs, because they are mammals. Their lungs, retinas, laryngeal nerves... get the idea?

Comments, kingsfan?

premjan

It is interesting that as a vegetarian, large antlers really are a signal of good health and strength as they are difficult to grow. It is also interesting that there needs to be something in the female deer genotype that actually recognizes and favors large antlers. I wonder if such a segment of the genome will actually be found and it will be possible to trace the original accidental mutation that caused it. It seems awfully specific to be able to trace visual recognition of large antlers to some genetic sequence.

Oolon Colluphid

Nitpick: It's the phenotype that does the selecting, of course.
Awfully specific... and unnecessary. All that is needed is recognition of whatever counts as a sign of health or virility.

There’s no need for a genetic sequence for specifically recognising length of a peacock’s tail, quality of a bowerbird’s bower or even body size in a male copepod. Females just need to recognise ‘that which counts as a good mate’. The genes involved will be dealing with brain wiring for good mate spotting, not for spotting any particular feature itself.

premjan

The fact that deer are not as intelligent as humans indicates that there is some specificity to their pattern recognition abilities (it is not general purpose). Recognizing a "healthy mate" is a capability whose genotype would not change at all after a large-antler mutation, so I think it would be necessary to invoke a genetic explanation for the shift that considered males with large antlers to be good mates.

RBH

Premjam wroteIt's an instance of sexual selection, an inherited preference for some feature associated with the males. It is almost certainly the product of an interaction among a slew of genes, rather than being a single genetic sequence. We know a whole lot of stuff is heritable, including perceptual stuff -- human babies are born able to recognize human faces, for example, and chicks of some prey species are born sensitized to overhead shadows like those associated with hawks and owls or to adult alarm calls, and herring gull chicks are born sensitized to a red spot on mother's bill -- so it doesn't seem like much of a stretch for female deer to recognize and inherit a preference for differences in male racks.

RBH