By the way, 'lower animals' isn't the preferred nomenclature in biology anymore. They have had a comparable amount of evolutionary time to specialize in their own things (maybe even effectively more if they have larger populations or smaller generation times), and they are more refined at some stuff while humans are more refined at other stuff (like advanced sweat pores and big brain).
Humans: lose our ancestral abilities of limb regeneration
Also humans: call our distant cousins who didn't lose those abilities as 'lower'
If you ever take courses for a degree in a science like biology, chemistry, or physics, you will often run into stuff like this. We are insanely pedantic about precise terminology because we have to be. If you don't speak carefully you can say something entirely different from what you mean.
To a lay-person it seems like we are just being know-it-all jerks. But it's actually really important to use proper terminology when communicating science information. Scientists spend a lot of their time just learning proper terminology and how to communicate properly. Stuff like the difference between precision and accuracy, centrifugal and centripetal forces, etc...
A good example of this is, that niacin used to be called nicotinic acid. As a result, many people tried to supplement niacin by smoking nicotine. When we communicate scientific concepts to lay-persons we have to be EXTRA careful. We had to language revise and rename the vitamin as niacin to prevent misunderstanding.
> When we communicate scientific concepts to lay-persons we have to be EXTRA careful. We had to language revise and rename the vitamin as niacin to prevent misunderstanding.
If you're cultivating a herd of uneducated emotion-driven stressed-out people by destroying education, getting everyone hooked on addictive social media and killing the economy every couple years, then yeah, you got to be careful. Better put that "do not eat" sticker on a box of moth balls.
But I think we'd be better off teaching people how to think properly, than trying to dumb down everything to a level of a toddler.
You can't be an expert on everything. Everyone is a lay-person in something. I used to scoff at warning labels myself until I realized that some people grow up without the benefit of parents or education. Those things that we think are obvious are, very often, not. We learned them from someone who cared about us.
Sure, but our effort should be put into making an education and learning accessible to those people, instead of normalizing stupidity by restricting everyone else's language.
Language by necessity must be restricted for it to have meaning. If a word can mean anything, it has exactly no meaning. By creating your own definition of the word you now must define it clearly otherwise you will spend all day arguing about "No True Scotsman".
What biologists have done in this case is removed the definition of "Lower Animals" from their context because there was no agreed upon definition of "Lower Animal." The term was too vague and could not be defined properly and was useless for scientific communication. There was no way to taxonomically define a "Lower Animal" except in a biblical sense. Even then, few can agree what it actually means.
I don't understand how the hypothesis that they are the same was under consideration. This seems sort of obvious to me that fingernails, antlers, hair, and other keratin growths aren't the same as growing bones and limbs. But I know little about the area -- what am I missing in my hasty, armchair thoughts?
"Each antler grows from an attachment point on the skull called a pedicle. While an antler is growing, it is covered with highly vascular skin called velvet, which supplies oxygen and nutrients to the growing bone. Antlers are considered one of the most exaggerated cases of male secondary sexual traits in the animal kingdom, and grow faster than any other mammal bone. Growth occurs at the tip, and is initially cartilage, which is later replaced by bone tissue. Once the antler has achieved its full size, the velvet is lost and the antler's bone dies. This dead bone structure is the mature antler. In most cases, the bone at the base is destroyed by osteoclasts and the antlers fall off at some point. As a result of their fast growth rate, antlers are considered a handicap since there is an immense nutritional demand on deer to re-grow antlers annually, and thus can be honest signals of metabolic efficiency and food gathering capability."
> They found a group of cells – called PMCs – believed to be crucial for limb regeneration in frogs and salamanders – to be abundant in deer antlers as well as in the tips of mouse digits.
So there's some positive evidence behind the mechanism being similar -- the same sort of cells are responsible for regeneration in deer and frogs. Which leads us to the question, how similar is this process? That was investigated by the scientists, who found that the source of PMCs to be different:
> However, the researchers also discovered that the PMCs in antler-generating tissues were formed by a sharply different process to lower-order vertebrates, according to the study.
The article continues in some detail as to the specific differences.
I think you are right. The only difference from fingernails is that when the antlers fall off there is bleeding. I get drops of blood where I feed the deer especially when they spar cross-pack. When they shed their antlers and some of them have bloody nubs that heal then form a smooth round nub and then the cycle repeats.
> I think you are right. The only difference from fingernails is that when the antlers fall off there is bleeding.
This is far from the only difference, starting from the material (living bone tissue vs non-living keratin), and process of growth (the living tissue grows and branches like a tree, vs. being extruded like from a 3D printer by a special tissue at the root of the nail).
Hair and nails are the same. Antlers are very unlike those two. Horns are a mixture, with a keratin shell covering living bone tissue.
I do not disagree with the composition. The reason I compare them to fingernails is that when a tip breaks off the tip does not regenerate. The broken tip remains broken. The antler may continue to grow out from the base but the tip will stay gone until they shed and regrow new antlers.
But the point was that I don't think they grow out from the base but instead from the tips! Branching wouldn't even be possible otherwise. A broken off antler tip may not regenerate, yes, but the reason is more like it develops scar tissue over the wound rather than just being made of inanimate protein like nails are.
Your comment reminds me of Steve Carrel’s character in “The Forty-Year-Old Virgin” when he inadvertently reveals his virginity by opining that women’s breasts feel like bags of sand.
Nobody could ever confuse an antler - with skin, hair, blood, and bone — with a fingernail.
Yup and since humans trim or pick at their nails they don't get long enough to rip out as easily. I assume people with the extreme cases of YNS probably bleed when those gnarly nails get caught on things.
Deer antlers shed even when they are tiny. I have a box full of their tiny ones that a neighbor turns into artwork.
I just kind of assumed antlers grew like nails. Sharks grow new teeth all the time. I don't see why "regeneration" would ever be involved in the first place.
What's interesting with antlers is if one of them is cut or damaged in a certain way, when both fall off later and regrow, both will grow into the shape of the damaged antler.
Well, because your assumption was false. Antlers grow nothing like nails and hair which do share the same mechanism. Ruminant horns are a mix of the two, with a hard keratin shell covering living tissue.
Not an expert but if I was to guess logically, it's because of their function in the first place: it's an immense waste of resources to grow them, so being able to do so proves the individual is a healthy male, worthy of passing on his genes. Growing a new set of antlers each year (and each year it's a larger structure) proves how many resources you can accumulate and then waste, kinda similar to how lawns were maintained by medieval English lords: just to show that they can waste valuable land for nothing of value.
So if you think of the evolutionary pressure, there MUST have been some deer at some point that didn't shed their antlers. The question is: would a female choose a male that tries to be economical about it's resources and save the antlers for next year? Or would the female choose the male that can take that resource hit every year? It's kindof like asking present day women: do you prefer a male with a wasteful Lamborghini or a male with an economical VW or Toyota hybrid? I think we know what the answer is...
Also, biology has another angle to it, but I think this could have been overcomed evolutionary: the antlers grow form the top, so in order to keep the current antlers and then still grow them, the deer would have had to keep the velvet healthy. Being such large sharp tools, used for seasonal combat, keeping the velvet could be hard. I think this wouldn't have been un-surmountable if the deer chose this strategy, but I think my first explanation might be the most likely one.
I get that the velvet would have to die off, but the antlers are firm enough all mating season for battles, why not keep it year round? I think I may have a theory: deer antlers evolved to be too elaborate to maintain all year without hindering the animal's survival. Antlers can get caught in brush and trees when fleeing from a predator and prohibit escape through tight spaces. Horns on prairie / savannah creatures like bulls, ox and buffalo prob do not have to worry as much about fleeing through densely wooded environments. I suspect it also ensures the males will cooperate when not "in the rut".
Also, they're quite heavy and don't really offer protection like cows or buffalo's horns. They shed them so they can save energy to prepare for the next year's pair.
> It's kindof like asking present day women: do you prefer a male with a wasteful Lamborghini or a male with an economical VW or Toyota hybrid? I think we know what the answer is...
Would love to hear how "common knowledge" like this deals with circular dependencies. And since this is HN, please reply as quickly as possible, and only from first principles.
Problem: "present day woman" turns her head to the man stepping out of the lambo, who is shorter than the man in the hybrid, so she turns her head toward the taller man, who is driving a hybrid, so she turns her head toward the man stepping out of the lambo, who is shorter...
I can't remember if it was on here I saw it or on twitter, but a Moose shaking off it's antler is one of the more... uncomfortable... things I've seen:
Humans: lose our ancestral abilities of limb regeneration
Also humans: call our distant cousins who didn't lose those abilities as 'lower'