Basically, why do dogs have balck lips whereas people have pinkish lips? My 8 year old asked me, and I have no idea whatsoever why this is.
I don’t know, but if you want to impress, dog lips are called “flews.”
If memory serves, Desmond Morris discussed this topic in either The Naked Ape or The Human Zoo (I think it was the former). Sorry - I don’t have my “books that are older than me” collection right at hand. The gist of his hypothesis was that as humans became bipedal, female genitals became less visible and lost some of their “I gotta’ get me somma’ 'dat” value. So, through evolution, pinker lips became successful marks of beauty by basically imitating the now-tough-to-see labia (and they got bigger because engorged labia indicate arousal/readiness to mate).
Supplemental to this, Morris also discusses that women have larger breasts than other primates - again, because of bipedalism. The more pronounced breasts are an imitation of the buttocks, which are less pronounced in us vertical primates.
It should also be noted that hundreds of millions of people (or perhaps billions) don’t in fact have pink lips.
My dog has pink lips, a pink nose, and light brown eyes.
Rudolph had a red nose. A shiny one. Glowing, in fact, metaphorically.
But I digress from OP.
Because generally, even on some light coloured dogs, their skin is black (or grey), and the lips, as on humans are just a deeper shade of that skin colour.
let us know how your eight-year old takes this explanation.
And how you explained it.
There are a lot of possible explanations, but if it’s true that dog lips are black even when the skin is primarily pink, the simplest explanation is that dog breeders prefer it, or that it’s a wolf trait (in which case we could discuss natural selection possibilities).
It’s also possible that even if it’s true, it isn’t selected for. A lot of traits come as baggage along with other traits that are being selected for.
My dog, a rescue mutt that looks like it might be from Llewellen setter or Dalmaitian stock, has mostly pink skin (black under the spots), and pink skin around his eyes. But (mostly) black lips, adding one data point to the “valid observation” column.
I think you have this wrong or misinterpreted in some way; I don’t know what the original theory actually says, but humans have proportionately larger buttocks than any other primate, because we’re bipedal.
I could handle that. “People have pink lips because people like to kiss them, but dogs don’t kiss like people do.”
BTW, it seems to me that most black people’s lips are pinker (or redder) than the rest of their skin, so the comment can be made without too much regard for race.
Comments on the above:
(1) Forget Desmond Morris - he’s mostly full of crap.
(2) Not all dogs have black lips, and I’d say more than half of humanity’s lips are not pink.
(3) The ultimate answer to questions of this type (“why is [some physiological feature] like this and not like that?”) is usually “why not?” Evolution is like that.
(4) The proximal answer to the kid’s question is “Most people you know have pink lips because they have pale skin; the lips are very thin-skinned, and have lots of tiny blood vessels close to the surface, so when the skin is pale you can see the red color. Dogs have thicker skin on the part of the lips that you can see, and for some reason most of the dogs you’ve seen have dark skin on their lips. Some dogs have pale skin on their lips, and their lips are pink, though not as pink as yours or mine.”
Off topic, but I used to have a cat named Lips. His lips were black.
Yep.
Speaking of crap, is it possible that dogs have black lips so potential mates can’t tell whether or not they’ve recently eaten cat shit?
Probably not. I think dogs make their courtship choices based on factors such as: “This bitch (or son of a bitch) knows where the good cat shit is? Hubba-Hubba!”
Carnivores tend to have black lips. Look at pictures of lions, leopards, tigers, bears, wolves- their lips are black. Herbivores typically do not have black lips.
Wolves, as well as other carnivores, evolved black lips because it makes the teeth stand out more dramatically than pink lips, which makes them appear more ferocious.
Dogs that do not have black lips have simply not retained that particular ancestral trait, but most have.
Why would a carnivore want to advertise the fact like that? That is, what evolutionary advantage would a carnivore have by looking more ferocious?
I would think they would want to be less conspicuous. Wouldn’t stealth be more of an advantage?
Biped got back.
Finding adequate prey isn’t the only selector for evolution in carnivores. They also have to win mates (either by fighting off other suitors or seeming more desirable to the mate). That’s where looking ferocious would be helpful.
As for finding prey, the black lips aren’t enough of a disadvantage to outweigh their reproductive benefits.
Toss in Morris’ Dogwatching and Catwatching. Fun books… And, alas, also full of crap.
Stupid question: for people who do not have pink lips…are their lips the same color as their genitals? (I know I could get an answer on a porn site, but, ew.)