# Dog Lips **URL:** \ **Category:** Factual Questions\ **Created:** [March 13, 2013, 12:36pm UTC](https://boards.straightdope.com/t/dog-lips/652809 "2013-03-13T12:36:09Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![TreacherousCretin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/treacherouscretin/32/476_2.png) [@TreacherousCretin](https://boards.straightdope.com/u/TreacherousCretin)\ **Post date:** [March 14, 2013, 2:32am UTC](https://boards.straightdope.com/t/dog-lips/652809/21 "2013-03-14T02:32:23Z")
> [@kaylasdad99](#): > > 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!”_ Oh hell. You’re probably right. So much for my theory. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [March 14, 2013, 4:37am UTC](https://boards.straightdope.com/t/dog-lips/652809/22 "2013-03-14T04:37:36Z")
> [@Trinopus](#): > > 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.) Great pick-up ice breaker. I’ll add that to “So, do the curtains match the rug?” ---
**Author:** ![Turpentine](https://avatars.discourse-cdn.com/v4/letter/t/ecd19e/32.png) [@Turpentine](https://boards.straightdope.com/u/Turpentine)\ **Post date:** [March 14, 2013, 12:55pm UTC](https://boards.straightdope.com/t/dog-lips/652809/23 "2013-03-14T12:55:30Z")
> [@dstarfire](#): > > 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. Yep. All this. Also to deter larger carnivores and for juveniles to be less likely to be bothered by older members of their species. Showing off your vivid white teeth is often a way to avoid a fight. Sometimes if you look ferocious enough, you don’t have to fight, which means you can save that energy for hunting or producing more offspring. Most animals in fact will do whatever they can to avoid a fight by displays and posturing. Fighting is only a last resort. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [March 14, 2013, 4:13pm UTC](https://boards.straightdope.com/t/dog-lips/652809/24 "2013-03-14T16:13:07Z")
I like the “show off your teeth” hypothesis. Unfortunately, a lot of questions about evolution of traits come down to “just-so” stories that sound good but are difficult to test. I like hearing the stories anyway. ---
**Author:** ![Mr.Milton](https://avatars.discourse-cdn.com/v4/letter/m/6bbea6/32.png) [@Mr.Milton](https://boards.straightdope.com/u/Mr.Milton)\ **Post date:** [March 15, 2013, 12:10pm UTC](https://boards.straightdope.com/t/dog-lips/652809/25 "2013-03-15T12:10:45Z")
I don’t think we’re getting to an asnwer… To clarify, I wasn’t interested in humans, bipedalism, buttocks, or breasts. (For the purposes of the question, that is.) I did make the offhand remark about humans having pink or pinkish lips, but that was only to contrast human lip color with dogs. There may be some humans with less than pink or pinkish or red lips, but it’s besides the point. The question remains “Why do dogs have black lips?” Our dog is a cockapoo, a poodle-cocker mix. His fur is principally white, with buff (tan) spots. Before that, we had a cocker who was all buff (tan) furred. FWIW, both had skin under tha hair that was pinkish spotted aparently randomly with dark tan/brown splotches. This seems to my observation to be rather common among dogs. As do the black lips. And when I say, black, I mean black like rubber O-rings. Black like black ink, not dark brown, not anything else. Actually black, not some euphemism from (human) racial naming conventions. If it had something to do with capillaries, then it seems to me that their lips would be some sort of variation of red, but they aren’t. Sun exposure wouldn’t get it either, because both our dogs were/are indoors way more than out, and besides, the setup of their faces keeps their mouths in the shadow of their muzzles rety much continuously. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [March 15, 2013, 2:34pm UTC](https://boards.straightdope.com/t/dog-lips/652809/26 "2013-03-15T14:34:28Z")
It’s speculation, but what’s wrong with the “to show off their teeth” answer? Of course, the correct answer is “I don’t know.” 😉 ---
**Author:** ![sidhechaos](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@sidhechaos](https://boards.straightdope.com/u/sidhechaos)\ **Post date:** [March 17, 2013, 10:08pm UTC](https://boards.straightdope.com/t/dog-lips/652809/27 "2013-03-17T22:08:29Z")
> [@GiantRat](#): > > 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. somewhere in my head (probably the gutter portion) my brain mentions that natural lip color often matches nipple color as well. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [March 17, 2013, 10:19pm UTC](https://boards.straightdope.com/t/dog-lips/652809/28 "2013-03-17T22:19:00Z")
My Golden one day had a big pink splotch on one of his jet black lips. Vet said something like “color flakes off sometime.” Have no idea how that works, but it should be noted for the purposes of this thread. [Previous page](https://boards.straightdope.com/t/dog-lips/652809.md?page=1)