# At which point in our evolution did we lose our tail ? **URL:** \ **Category:** Factual Questions\ **Created:** [July 23, 2012, 9:59pm UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173 "2012-07-23T21:59:01Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [July 23, 2012, 9:59pm UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/1 "2012-07-23T21:59:01Z")
How do we know that the apes we descend from, maintained a tail (maybe vestigal) far the evolution steps ? Is there direct evidence that the tailless monkeys in our evolution steps are indeed tailless ? ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [July 23, 2012, 10:31pm UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/2 "2012-07-23T22:31:55Z")
All the other apes (chimpanzees, gorillas, orangutans and gibbons) are tailless, which suggests that their ancestors, after they split off from the monkeys, were all tailless. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [July 23, 2012, 10:49pm UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/3 "2012-07-23T22:49:45Z")
I find a little tail every Sat night. šŸ˜ƒ A Swinging good time. ---
**Author:** ![Foggy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foggy/32/1082_2.png) [@Foggy](https://boards.straightdope.com/u/Foggy)\ **Post date:** [July 23, 2012, 11:11pm UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/4 "2012-07-23T23:11:25Z")
> [@aceplace57](#): > > I find a little tail every Sat night. šŸ˜ƒ A Swinging good time. Does your wife know? ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 24, 2012, 12:43am UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/5 "2012-07-24T00:43:44Z")
The best known early ape (or perhaps close ape relative) was[_Proconsul_,](http://en.wikipedia.org/wiki/Proconsul_(primate))which originated about 23 million years ago. Like later apes, it lacked a tail. Since being tailless is one of the defining characteristics of apes vs monkeys, we can say that the apes we descended from lacked tails. (A few species of monkeys also lack tails.) ---
**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\ **Post date:** [July 24, 2012, 12:49am UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/6 "2012-07-24T00:49:01Z")
Is ā€œtailed vs. taillessā€ a distinct branching point in our ancestry? Or have tails gone and come again in some lines of apes/monkeys? (Isnā€™t the same true for zebras and other striped horses? There are both striped and unstriped equines along lineages, so that ā€œstriped/unstripedā€ isnā€™t a primary branching distinction. I _think_ thatā€™s what Stephen Jay Gould said in his essay on the subject.) ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [July 24, 2012, 12:57am UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/7 "2012-07-24T00:57:18Z")
> [@Trinopus](#): > > Is ā€œtailed vs. taillessā€ a distinct branching point in our ancestry? Or have tails gone and come again in some lines of apes/monkeys? AFAWK, yes. As noted, ā€œtaillessā€ is one of the attributes of an ape. > [@](#): > > (Isnā€™t the same true for zebras and other striped horses? There are both striped and unstriped equines along lineages, so that ā€œstriped/unstripedā€ isnā€™t a primary branching distinction. I _think_ thatā€™s what Stephen Jay Gould said in his essay on the subject.) Yep. " Zebra" is a [paraphyletic](http://en.wikipedia.org/wiki/Paraphyletic) term. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [July 24, 2012, 12:57am UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/8 "2012-07-24T00:57:43Z")
> [@Trinopus](#): > > Is ā€œtailed vs. taillessā€ a distinct branching point in our ancestry? Or have tails gone and come again in some lines of apes/monkeys? > > (Isnā€™t the same true for zebras and other striped horses? There are both striped and unstriped equines along lineages, so that ā€œstriped/unstripedā€ isnā€™t a primary branching distinction. I _think_ thatā€™s what Stephen Jay Gould said in his essay on the subject.) Great question - I had similar thoughts. Also, Colibri - can you please elaborate how did they deduce it had no tail by looking at the skeleton? ---
**Author:** ![Speaker\_for\_the\_Dead](https://avatars.discourse-cdn.com/v4/letter/s/c77e96/32.png) [@Speaker\_for\_the\_Dead](https://boards.straightdope.com/u/Speaker_for_the_Dead)\ **Post date:** [July 24, 2012, 1:19am UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/9 "2012-07-24T01:19:47Z")
> [@am77494](#): > > Great question - I had similar thoughts. Also, Colibri - can you please elaborate how did they deduce it had no tail by looking at the skeleton? Iā€™m no expert, but the skeleton having no tail would be clue #1. Thatā€™s not as sarcastic as it soundsā€“you can tell where the (appropriately named) tailbone attaches and ends if you have a pelvis to look at. I presume they have other skeletons than the ones shown in the Wiki articles, with parts or whole pelvises. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 24, 2012, 2:29am UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/10 "2012-07-24T02:29:03Z")
> [@am77494](#): > > Great question - I had similar thoughts. Also, Colibri - can you please elaborate how did they deduce it had no tail by looking at the skeleton? As **Speaker** says, you can tell by looking at the sacrum and pelvis. Although most internet references said Proconsul was tailless, apparently this has been somewhat controversial. [Recent evidence](http://tech.groups.yahoo.com/group/paleoanthropology/message/13135) apparently confirms that it didnā€™t have a tail. Whether or not Proconsul had a tail, by 15 million years ago it seems that apes had definitely lost their tails. [QUOTE=Trinopus] Is ā€œtailed vs. taillessā€ a distinct branching point in our ancestry? Or have tails gone and come again in some lines of apes/monkeys? [/QUOTE] In apes, it seems that once the tail was lost it was never regained. As I mentioned, a few monkeys have also lost their tails independently. I am not aware that any monkey has re-evolved a tail once having lost it. ---
**Author:** ![rsat3acr](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@rsat3acr](https://boards.straightdope.com/u/rsat3acr)\ **Post date:** [July 24, 2012, 3:13am UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/11 "2012-07-24T03:13:24Z")
we did not decend FROM apes, we share acommon ancestor with them. ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [July 24, 2012, 3:15am UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/12 "2012-07-24T03:15:15Z")
> [@rsat3acr](#): > > we did not decend FROM apes, we share acommon ancestor with them. Well, strictly speaking, we ARE apes. Of course, depending on your taxonomical philosophy, weā€™re fish, too. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 24, 2012, 3:31am UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/13 "2012-07-24T03:31:01Z")
> [@rsat3acr](#): > > we did not decend FROM apes, we share acommon ancestor with them. We did not descend from any _living_ ape. But yes, the animals we did descend from are extinct species that are classified as apes. As **jayjay** says, that makes us taxonomically speaking apes. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [July 24, 2012, 4:33am UTC](https://boards.straightdope.com/t/at-which-point-in-our-evolution-did-we-lose-our-tail/629173/14 "2012-07-24T04:33:08Z")
> [@rsat3acr](#): > > we did not decend FROM apes, we share acommon ancestor with them. Were our ancestors\* not apes? They were. Hence, we descend from apes. We can still be apes, descended from apes. \*back at least 20M years.