# IF Homo Sapiens were wiped off the planet would any other species become extinct? **URL:** \ **Category:** Factual Questions\ **Created:** [September 24, 2002, 8:43pm UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515 "2002-09-24T20:43:33Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Agback](https://avatars.discourse-cdn.com/v4/letter/a/977dab/32.png) [@Agback](https://boards.straightdope.com/u/Agback)\ **Post date:** [September 25, 2002, 1:26am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/21 "2002-09-25T01:26:50Z")
> [@](#): > > \*Originally posted by boo1377 \* > \*\*Is there a species that is so depedant on humans that it would become extinct if humans became extinct? > 😕 \*\* Well, for a start all the parasites that are specialised entirely to humans would go: head lice, pubic lice, a kind of microscopic louse that lives olnly in human eyelash-follicles… And the micro-organisms that cause certain diseases that affect only humans would go too. I don’t know whether you count viruses as living or as belonging to species, but there are some viral quasi-species that are entirely specialised to a human host, too. Apart from that, I can think of two domesticated animal species for which no wild conspecifics exist, and that have never established feral populations anywhere: silkworms and ferrets. Then, there are some plant species that were produced by selective breeding (I know what I said, and I meant it), and that are in various ways ill-suited to propagate themselves. The most conspicuous is maize. Wheat is not quite so dependent on agriculture for survival, but it would probably succumb to competition in time. Regards, Agback ---
**Author:** ![AK47Mac](https://avatars.discourse-cdn.com/v4/letter/a/4491bb/32.png) [@AK47Mac](https://boards.straightdope.com/u/AK47Mac)\ **Post date:** [September 25, 2002, 5:41am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/22 "2002-09-25T05:41:08Z")
> [@](#): > > \*Originally posted by Wearia \* > \*\* > I heard somewhere that some house cats have become completely dependant on humans because of some chemical imbalance or a genetic disorder or something. So they’ll die. \*\* I don’t buy that. When people in my area have a cat that they don’t want anymore instead of giving it away, they instead dump them in the desert. I have personally seen these cat’s miles from civilization hunting for prey. They’re not real healthy looking, but they are living without any human intervention. ---
**Author:** ![elfkin477](https://avatars.discourse-cdn.com/v4/letter/e/a9a28c/32.png) [@elfkin477](https://boards.straightdope.com/u/elfkin477)\ **Post date:** [September 25, 2002, 6:12am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/23 "2002-09-25T06:12:26Z")
> [@](#): > > \*Originally posted by Agback \* > \*\* Apart from that, I can think of two domesticated animal species for which no wild conspecifics exist, and that have never established feral populations anywhere: silkworms and ferrets. > \*\* Ferrets were one of the first things that sprang to mind. I’m not entirely sure how accurate it is, but one of the ferret books I read suggested that domestic ferrets, unlike some other species of domestic animals, never existed in the wild, because they were the result of selectively cross-breeding two types of weasels from different continents, pole cats and some type of european ferret now extinct. The biggest thing that would led to their doom as a species is some states, if not all, that make them legal to own as pets (I only have had to deal with state laws in 3 states regarding them) require that they _must_ be sterilized in order to be sold for pets. Only breeders with permits are allowed to own unsterilized ferrets. So considering that in at least 3 of the states that they’re legal in, probably more, 99% of them can’t reproduce, they’d probably all die off within 12 years of the humans. ---
**Author:** ![chique](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@chique](https://boards.straightdope.com/u/chique)\ **Post date:** [September 25, 2002, 10:35am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/24 "2002-09-25T10:35:02Z")
> [@](#): > > \*Originally posted by clayton\_e \* > \*\*Maize (pretty much any species of corn) would become extinct because it has been domesticated by selective breeding. > The corn which it first came from had curnels which were far apart, making it easy for them to fall and grow. Our ancestors were able to selectively breed the corn to have more curnels on each stalk. > This made it impossible for the corn to fall, it was just too packed together. Corn, as we know it, will die after we’re gone because it can’t spread it’s own seeds. Perhaps a few wild versions of it will survive, but that’s if they’re still in existance (a fact that I don’t know). > > Also some forms of lice will become extinct if mankind is gone. \*\* I don’t believe this. I’ve seen too much corn growing around grain bins from spilled harvests and too much corn growing in soybean fields (it’s called volunteer corn…stuff that grows despite the fact the soil has been tilled and sprayed for weeds). Never mind the couple of acres my father planted a few years ago to feed deer and game birds. It doesn’t grow in straight lines or as tall anymore, but it’s still there. However. Some company (Monsanto? ADM? I forget which.) has created a strain of corn which renders the seed sterile, the idea being producers would HAVE to buy seed corn. I think (well, hope at least) the furor was big enough for the company to can the idea, but it would be an ecological horror if that stuff was ‘set free in the wild’, as it were. ---
**Author:** ![Weeks](https://avatars.discourse-cdn.com/v4/letter/w/bbce88/32.png) [@Weeks](https://boards.straightdope.com/u/Weeks)\ **Post date:** [September 25, 2002, 11:11am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/25 "2002-09-25T11:11:22Z")
> [@](#): > > There are various human-specific parasites (mites, lice, worms, even protozoans I believe). LAWYERS! IRS agents! Pedophiles! Mary Kay ! Telemarketers. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [September 25, 2002, 11:34am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/26 "2002-09-25T11:34:19Z")
I have just finished harvesting my sweetcorn (which was a modern variety); most of the cobs were perfect, but some (from the edges of the block) were imperfectly pollinated and were only sparsely populated with fertilised kernels - two-thirds were missing/infertile (it is also not uncommon to find a small cluster of viable kernels with no husk at the base of (what is supposed to be) the male flowering panicle - there were at least three examples of this in my little plot of about 50 plants - there’s a picture of it in Roger Phillips book: _[Vegetables](http://www.amazon.com/exec/obidos/tg/detail/-/067975024X/qid=1032953145/sr=1-3/ref=sr_1_3/103-0126057-5600628?v=glance)_, but I am unable to find an online image of the phenomenon); Certainly sweetcorn/maize forms as we now know them would not last long, but I strongly suspect it would chance to survive (although probably not in my locality as it is not native here) enough generations to revert to something similar to wild types. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [September 25, 2002, 11:38am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/27 "2002-09-25T11:38:52Z")
> [@](#): > > \*Originally posted by chique \* > However. Some company (Monsanto? ADM? I forget which.) has created a strain of corn which renders the seed sterile, the idea being producers would HAVE to buy seed corn. I think (well, hope at least) the furor was big enough for the company to can the idea, but **it would be an ecological horror if that stuff was ‘set free in the wild’, as it were. > [sup](emphasis added)[/sup]** I’m not sure how that could be - if it were released into the wild it would simply become extinct in a single generation and everything would carry on as normal. Or did you mean something else? ---
**Author:** ![Bob\_Scene](https://avatars.discourse-cdn.com/v4/letter/b/e19adc/32.png) [@Bob\_Scene](https://boards.straightdope.com/u/Bob_Scene)\ **Post date:** [September 25, 2002, 11:46am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/28 "2002-09-25T11:46:09Z")
There are some species of _Plasmodium_, the protozoa that cause malaria, that only infect people. (And mosquitos.) ---
**Author:** ![smiling\_bandit](https://avatars.discourse-cdn.com/v4/letter/s/e9a140/32.png) [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)\ **Post date:** [September 25, 2002, 12:05pm UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/29 "2002-09-25T12:05:59Z")
> [@](#): > > Santa Cantalina foxes? Since foxes have never been succesfully domesticated, how can these ones not be able to breed in the wild? Are they just that rare they can’t find mates? Foxes have been one of the most successful animals in all of history; they are like large rat-dogs in terms of human coexistance. > [@](#): > > I’m not sure how that could be - if it were released into the wild it would simply become extinct in a single generation and everything would carry on as normal. Or did you mean something else? I think he’s worried about crosspollination. But I seriously doubt it could ever do much of that, since it dies off after one season and thats all, folks. ---
**Author:** ![El\_Elvis\_Rojo](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@El\_Elvis\_Rojo](https://boards.straightdope.com/u/El_Elvis_Rojo)\ **Post date:** [September 25, 2002, 12:16pm UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/30 "2002-09-25T12:16:51Z")
> [@](#): > > \*Originally posted by astorian \* > \*\*The only animals that would have a hard time are domesticated dogs especially the toy and “frou frou” breeds, many of whom have no survival skills and have never learned to hunt or forage. But the species would not die out. Over time, the dogs with the best instinct for survival would find each other, form packs, and revert to long-forgotten wolf-like behavior. \*\* I just have this image of a pack of wild chihuhuas ravaging the countryside. ---
**Author:** ![woolly](https://avatars.discourse-cdn.com/v4/letter/w/ebca7d/32.png) [@woolly](https://boards.straightdope.com/u/woolly)\ **Post date:** [September 25, 2002, 12:56pm UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/31 "2002-09-25T12:56:49Z")
> [@](#): > > \*Originally posted by Nametag \* > \*\*I dunno; don’t you think **sheep** would be in trouble? They’re so slow, so fleecy, so stupid… \*\* Watch it buster, who ewe calling stupid? 😃 Many breeds and cultivars would die out quickly, but the species would find niches. Near extinct species that require captive breeding programs would be obvious candidates. Plants like cultivated grapes, being almost exclusively grafted, would struggle as would other hybrid fruits/vegetables/animals e.g. mules, but they wouldn’t be classified as species. A number of viruses/bacteria exclusively human diseases (e.g. AIDS?) would die out or mutate back into feral populations. That SDMB reference classic “Guns, Germs and & Steel” points out how few other species we depend on and obviously only a tiny proportion of them depend exclusively on us. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [September 25, 2002, 3:33pm UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/32 "2002-09-25T15:33:29Z")
> [@](#): > > I just have this image of a pack of wild chihuhuas ravaging the countryside. They’d be like those packs of little dinosours in the second Jurassic park movie: small, quick, lots of sharp teeth, and totally amoral. I find this idea… disturbing. ---
**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:** [September 25, 2002, 3:54pm UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/33 "2002-09-25T15:54:19Z")
> [@](#): > > \*Originally posted by Dooku \* > \*\*Also, I imagine all species currently on the endangered list wouldn’t make it, especially those who cannot mate in the wild - Giant Pandas, California Sea Otters, Santa Catalina foxes and buffalo, etc. \*\* What are you talking about? All those species reproduce in the wild. _Most_ endangered species would cease to be endangered if humans left the scene. > [@](#): > > _Originally posted by Agback_ > \*\*Apart from that, I can think of two domesticated animal species for which no wild conspecifics exist, and that have never established feral populations anywhere: silkworms and ferrets. > \*\* Not true for ferrets. Domesticated ferrets were intentionally introduced in New Zealand to control rabbits, and feral populations are now a considerable problem. Feral populations have also been established in other places. ---
**Author:** ![zephonith](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@zephonith](https://boards.straightdope.com/u/zephonith)\ **Post date:** [September 25, 2002, 3:58pm UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/34 "2002-09-25T15:58:12Z")
> [@](#): > > _Originally posted by elfkin477_ > \*\*Ferrets were one of the first things that sprang to mind. I’m not entirely sure how accurate it is, but one of the ferret books I read suggested that domestic ferrets, unlike some other species of domestic animals, never existed in the wild, because they were the result of selectively cross-breeding two types of weasels from different continents, pole cats and some type of european ferret now extinct. > > The biggest thing that would led to their doom as a species is some states, if not all, that make them legal to own as pets (I only have had to deal with state laws in 3 states regarding them) require that they must be sterilized in order to be sold for pets. Only breeders with permits are allowed to own unsterilized ferrets. So considering that in at least 3 of the states that they’re legal in, probably more, 99% of them can’t reproduce, they’d probably all die off within 12 years of the humans.\*\* Over here, it’s their very [adaptability to the wild](http://www.doc.govt.nz/Conservation/002~Animal-Pests/Mustelids-(ferrets,-stoats-and-weasels)/index.asp) which has led to them being [banned as pets](http://www.doc.govt.nz/Whats-New/Issues/Ferret-Breeding-and-Sales-Banned.asp). Of course, this is only because of the unique environment (no large predators + lots of relatively easy to catch prey) but here at least, ferrets are adapting to the wild. So even if humans got completely wiped out, they’d still survive over here (and in the process kill off all the endangered native birds) I’m finding it surprisingly difficult to come up with whole species that would disappear as a result of humans leaving. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [September 25, 2002, 4:10pm UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/35 "2002-09-25T16:10:21Z")
> [@](#): > > \*Originally posted by smiling bandit \* > \*\*I think he’s worried about crosspollination. But I seriously doubt it could ever do much of that, since it dies off after one season and thats all, folks. \*\* Pretty sure that fleetingly crossed my mind way back in that GM foodstuffs thread (the one where I mentioned it and got my arse (or rather, my argument) soundly whipped by some professionals in the field). Because the gene causes sterility, it can only really wipe itself out. ---
**Author:** ![gonzoron](https://avatars.discourse-cdn.com/v4/letter/g/a6a055/32.png) [@gonzoron](https://boards.straightdope.com/u/gonzoron)\ **Post date:** [September 25, 2002, 8:33pm UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/36 "2002-09-25T20:33:58Z")
> [@](#): > > \*Originally posted by woolly \* > \*\* > Plants like cultivated grapes, being almost exclusively grafted, would struggle as would other hybrid fruits/vegetables/animals e.g. mules, but they wouldn’t be classified as species. > \*\* Anything seedless would die out quick: grapes, watermelon, oranges. All produced by grafting. Of course the original varieties would be fine. If viruses count, I suppose HIV would finally be “cured”. And now my wiseass answer: Tomagotchi ---
**Author:** ![Threadkiller](https://avatars.discourse-cdn.com/v4/letter/t/aca169/32.png) [@Threadkiller](https://boards.straightdope.com/u/Threadkiller)\ **Post date:** [September 25, 2002, 9:16pm UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/37 "2002-09-25T21:16:11Z")
> [@](#): > > \*Originally posted by zephonith \* > …So even if humans got completely wiped out, [feral ferrets would] still survive over here [New Zealand] (and in the process kill off all the endangered native birds) > > I’m finding it surprisingly difficult to come up with whole species that would disappear as a result of humans leaving. Read these two paragraphs again. The prime candidates are animals that humans _almost_ wiped out by introduction of new predators and now only stay alive by active intervention keeping the animals sheltered from said predators. ---
**Author:** ![abby](https://avatars.discourse-cdn.com/v4/letter/a/48db29/32.png) [@abby](https://boards.straightdope.com/u/abby)\ **Post date:** [September 26, 2002, 5:50am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/38 "2002-09-26T05:50:50Z")
What about chooks (er, you Merkins call 'em “chickens” I think?). They are dumb, virtually flightless, and have no defence mechanisms. abby ---
**Author:** ![Silentgoldfish](https://avatars.discourse-cdn.com/v4/letter/s/e36b37/32.png) [@Silentgoldfish](https://boards.straightdope.com/u/Silentgoldfish)\ **Post date:** [September 26, 2002, 7:24am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/39 "2002-09-26T07:24:25Z")
Cows? ---
**Author:** ![zephonith](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@zephonith](https://boards.straightdope.com/u/zephonith)\ **Post date:** [September 26, 2002, 8:01am UTC](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515/40 "2002-09-26T08:01:01Z")
> [@](#): > > \*Originally posted by Threadkiller \* > \*\*Read these two paragraphs again. > > The prime candidates are animals that humans _almost_ wiped out by introduction of new predators and now only stay alive by active intervention keeping the animals sheltered from said predators. \*\* Sorry should have added a rolleyes smily there after the birds comment, so it’ll read > [@](#): > > So even if humans got completely wiped out, they’d still survive over here (and in the process kill off all the endangered native birds :rolleyes: ) I didn’t elaborate because I was just addressing the ferret thing. Someone else had already mentioned endangered species, so I meant I couldn’t add anything **new** to the list. Sorry for the misunderstandings, it’s probably the result of posting too early in the morning. That’ll teach me to stray into GQ… [Previous page](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515.md?page=1) [Next page](https://boards.straightdope.com/t/if-homo-sapiens-were-wiped-off-the-planet-would-any-other-species-become-extinct/129515.md?page=3)