# In terms of mass, are humans the most abundant species? **URL:** \ **Category:** Factual Questions\ **Created:** [February 7, 2007, 7:57pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253 "2007-02-07T19:57:46Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Ximenean](https://avatars.discourse-cdn.com/v4/letter/x/aca169/32.png) [@Ximenean](https://boards.straightdope.com/u/Ximenean)\ **Post date:** [February 7, 2007, 7:57pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/1 "2007-02-07T19:57:46Z")
Six billion people certainly sounds a lot, but somebody always seems to pipe up with “ah yes, but there are four _trillion_ houseflies in the world” or something. OK, so we may not be the most abundant in number, but it seems to me that for a large animal, _homo sapiens sapiens_ is not doing too badly. So if you put all humans on one side of a scale and all plankton, say, on the other, which way would it tip? And are we the most abundant vertebrate? ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [February 7, 2007, 8:03pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/2 "2007-02-07T20:03:34Z")
I think the [krill](http://ift.confex.com/ift/2005/techprogram/paper_29868.htm) win. ---
**Author:** ![pravnik](https://avatars.discourse-cdn.com/v4/letter/p/8edcca/32.png) [@pravnik](https://boards.straightdope.com/u/pravnik)\ **Post date:** [February 7, 2007, 8:05pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/3 "2007-02-07T20:05:16Z")
I’d guess there’s at least one or two species of roundworm that’s got us beat; roundworms are everywhere. If my memory of college biology serves me properly, roundworms are far, far more plentiful than we puny mammals, to the point that if everything else in the world were invisible but roundworms, we could still pretty see where everthing was by the roundwormy outline. That’s a phylum and not a species, but I don’t think identifying the thousands of individual roundworm species is currently a high priority in academia. ---
**Author:** ![mhendo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mhendo/32/3159_2.png) [@mhendo](https://boards.straightdope.com/u/mhendo)\ **Post date:** [February 7, 2007, 8:10pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/4 "2007-02-07T20:10:03Z")
What **UncleRojelio** said. From [Wikipedia](http://en.wikipedia.org/wiki/Biomass_%28ecology%29): > [@](#): > > The most successful animal, in terms of biomass, is the Antarctic krill, Euphausia superba, with a biomass of probably over 500 million tons, roughly twice the total biomass of humans. The entire earth contains about 75 billion tons of biomass. Humans comprise about 250 million tons (0.33%), domesticated animals about 700 million (1.0%), and crops about 2 billion tons or 2.7% of the Earth’s biomass. ---
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [February 7, 2007, 8:17pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/5 "2007-02-07T20:17:31Z")
Now if we could just find a way to use Krill as an alternate fuel. ---
**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:** [February 7, 2007, 8:22pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/6 "2007-02-07T20:22:14Z")
[QUOTE=Hampshire] Now if we could just find a way to use Krill as an alternate fuel. [/QUOTE] Considering their location, I think we’re heading the other way. They don’t like warm ocean temperatures. ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [February 7, 2007, 9:04pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/7 "2007-02-07T21:04:57Z")
Among land vertebrates, I suspect cows are right up there. There are an estimated 1.3 billion head of cattle (_Bos taurus_) in the world. Considering the size difference, world cattle biomass is probably pretty close to the world human biomass. If they ever learn how to use tools, we’re screwed. ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [February 7, 2007, 9:06pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/8 "2007-02-07T21:06:34Z")
I, for one, welcome our new bovine overlords! ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [February 7, 2007, 9:15pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/9 "2007-02-07T21:15:12Z")
> [@](#): > > Considering their location, I think we’re heading the other way. They don’t like warm ocean temperatures. In warm ocean, krill make fuel of _you_! ---
**Author:** ![Ximenean](https://avatars.discourse-cdn.com/v4/letter/x/aca169/32.png) [@Ximenean](https://boards.straightdope.com/u/Ximenean)\ **Post date:** [February 7, 2007, 9:34pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/10 "2007-02-07T21:34:42Z")
Hmm, so passing alien biologists, doing a survey of the outer arms of the galaxy, would label Earth as “that planet with all the krill”? I guess that’s what “mostly harmless” meant. ---
**Author:** ![levdrakon](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@levdrakon](https://boards.straightdope.com/u/levdrakon)\ **Post date:** [February 7, 2007, 10:22pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/11 "2007-02-07T22:22:41Z")
I’ve heard bacteria living under the seafloor could comprise 10-30% of the earth’s biomass, but I don’t know what the breakdown would be in terms of individual species. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [February 7, 2007, 10:29pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/12 "2007-02-07T22:29:04Z")
The other thing you need to look at is the tree population. I once did some back of the envelope calculations suggesting that a single tree species outweighs the human biomass by an order of magnitude. ---
**Author:** ![Cervaise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cervaise/32/16693_2.png) [@Cervaise](https://boards.straightdope.com/u/Cervaise)\ **Post date:** [February 7, 2007, 11:37pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/13 "2007-02-07T23:37:53Z")
Where do the ants rank? ---
**Author:** ![DanBlather](https://avatars.discourse-cdn.com/v4/letter/d/f4b2a3/32.png) [@DanBlather](https://boards.straightdope.com/u/DanBlather)\ **Post date:** [February 7, 2007, 11:41pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/14 "2007-02-07T23:41:08Z")
[QUOTE=Hampshire] Now if we could just find a way to use Krill as an alternate fuel. [/QUOTE] Or people. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [February 8, 2007, 12:00am UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/15 "2007-02-08T00:00:24Z")
According to this site [ants are certainly in the running.](http://www.madsci.org/posts/archives/may2001/989366143.En.r.html) ---
**Author:** ![Biffy\_the\_Elephant\_Shrew](https://avatars.discourse-cdn.com/v4/letter/b/e47c2d/32.png) [@Biffy\_the\_Elephant\_Shrew](https://boards.straightdope.com/u/Biffy_the_Elephant_Shrew)\ **Post date:** [February 8, 2007, 12:18am UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/16 "2007-02-08T00:18:23Z")
[QUOTE=David Simmons] According to this site [ants are certainly in the running.](http://www.madsci.org/posts/archives/may2001/989366143.En.r.html) [/QUOTE] Yeah, but you have to divide that up among the roughly 12,000 known species of ants. ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [February 8, 2007, 4:55am UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/17 "2007-02-08T04:55:22Z")
It’s not surprising that the Krill are so dominant. They’re super-intelligent. But they forgot about one thing - monsters from the id: > **[Forbidden Planet](https://en.wikipedia.org/wiki/Forbidden_Planet)** > > Forbidden Planet is a 1956 American science fiction film from Metro-Goldwyn-Mayer, produced by Nicholas Nayfack, and directed by Fred M. Wilcox from a script by Cyril Hume that was based on an original film story by Allen Adler and Irving Block. It stars Walter Pidgeon, Anne Francis, and Leslie Nielsen. Shot in Eastmancolor and CinemaScope, it is considered one of the great science fiction films of the 1950s, a precursor of contemporary science fiction cinema. The characters and isolated setti ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [February 8, 2007, 5:10am UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/18 "2007-02-08T05:10:18Z")
[QUOTE=bibliophage] Among land vertebrates, I suspect cows are right up there. There are an estimated 1.3 billion head of cattle (_Bos taurus_) in the world. Considering the size difference, world cattle biomass is probably pretty close to the world human biomass. If they ever learn how to use tools, we’re screwed. [/QUOTE] > **[Cows With Guns](https://www.albinoblacksheep.com/flash/cowswithguns)** > > Cows With Guns, a Flash Animated video by Bjørn-Magne Stuestøl ---
**Author:** ![Stan\_Doubt](https://avatars.discourse-cdn.com/v4/letter/s/53a042/32.png) [@Stan\_Doubt](https://boards.straightdope.com/u/Stan_Doubt)\ **Post date:** [February 8, 2007, 5:35am UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/19 "2007-02-08T05:35:50Z")
You have to keep in mind that humans, trees, ants, and krill only live within a fairly teeny band of the eath’s crust. There are many types of chemosynthetic bacteria that live WITHIN the earth’s crust, achieving a modest living by taking advantage of loopholes in the periodic table. You know, a little methane here, some sulfur there, a little iron, you didn’t fill out form F…Before you know it, you’ve got an ATP. Growing slowly but infinitely throughout the uppermost reaches of the earth’s crust, the combined biomass of chemosynthetic bacteria WITHIN the earth’s crust may outweigh the life ON earth’s crust by a significant margin. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [February 8, 2007, 2:58pm UTC](https://boards.straightdope.com/t/in-terms-of-mass-are-humans-the-most-abundant-species/391253/20 "2007-02-08T14:58:28Z")
[QUOTE=bibliophage] AIf they ever learn how to use tools, we’re screwed. [/QUOTE] [Larson]" …and here we sit, without opposable thumbs"[/Larson]