Are humans the most successful species ever?

Let me preface this question by stating that I am speaking in terms of biomass and not numbers. (In other words, if you put all humans in one big pile, and all of any other species in another big pile, which would be the biggest pile?)

I’m sure there may be insect species which are more numerous (and feel free to name some), but are there any which could challenge us in terms of total mass?

As far as extinct species are concerned, I expect the biggest challenger might be trilobites, BUT, were trilobites all one species, or do we even know?


Well, I’m the most succesful member of the species, anyway.

Humans aren’t even close. Any number of insect species beats us by orders of mangnitude. Ants, termites, cockroaches for starters.

Cockroaches have been around in basically the same form for 400 million years. We have a long way to go to catch up with that.

It’s scary to think about; only about one percent of all cockroaches make it a choice to dwell in the homes of hairless monkeys. That means that there is the other ninety-nine percent outdoors… I think I’ll stay indoors, thank you.

Aren’t beetles the most prolific of all animals? I heard somewhere that forty percent of all insect species are beetles, and while I know this may not exactly translate into sheer numbers (just diversity), I’m willing to believe it if it’s true. I’ve seen tons of beetle-like organisms where I live…

Dinosaurs are more successful than humans, been around for millions of years and instead of dying out some of them became birds (but I’m sure some would think this is debatable).

Ah, but when you’re talking about “cockroaches” or “ants,” you are talking about dozens of different species. Would any single species of those critters out-weigh us?

Same deal with dinosaurs. You’re talking about many, many species.

I should also clarify my question to refer to a “snapshot” - not the entire history of the species. In other words, if you piled up all the humans currently alive, and then piled up any other species, as it exists (or existed) on a given day in the history of the planet, which would be the bigger pile?

I’m open to the idea that particular species of cockroach or termite might top us, but I’ll need to see some evidence that you’re talking about a single species.

Bacteria top the list with everything else a distant second. Been around for +3.5 billion years, found in every environment (from a lake underneath the Anarctica ice sheet to boiling hot springs to miles underground), more prolific than every other organism. Stephen Jay Gould is quick to point out that it is our own multicellular biases that cause us to label the Paleozonic the age of fishes, the Mezazoic the age of reptiles, and the Cenezoic the age of mammals. All of them should be the age of bacteria.

Also, please note that I am not excluding plant species. Any single species of plants that tops us?

Dr. Lao, “bacteria” is also too non-specific. It is not a single species. Is there any particular species of bacterium which, at a given time, had more biomass than we currently do?

I’m surprised nobody’s mentioned krill.

spoke-, this is a damn interesting question. I wonder if biomass could be a reasonable basis for determining a species “success.” (whether or not you imply that, this just made me think of that)

It would seem that there are probably some insect species that are more prolific in terms of biomass, though. Are all cockroaches the same species? I don’t think they are…

But given the small protion of earth that human occupy I don’t think we can expect to hve the most mass.

Well, according to this site, Sultan Kinkari may be right about krill.

According to the site:

Of course, that site appears to be a second-grader’s school report, and I haven’t found anything to confirm it, but it is a good lead anyway.

Are krill all one species?

There’s some food for thought in this site as well.

So add earthworms to the list of candidates. Again, though, we run into the question of whether any one species of earthworms out-weighs us. The article doesn’t break the comparisons down by species.

Hmmm. Looks like [url=“”]krill comprise some 85 different species.

I say we’re still number one, baby! Go humans!


Krill comprise some 85 different species.

This site says that among species visible to the naked eye, the species Calanus hyperboreus has the largest biomass, with Euphausia superba being a close second. Looks like we, as a species, must bow down to the Copepods and Antartic krill.

My WAG would be that any of several species of Pine and Oak probably account for more biomass than the human race.

23skidoo, that site says that copepods in general have the highest biomass, not the species Calanus hyperboreus specifically. Copepods comprise many species. So we still have the problem of comparing humans, as one species, with groups made up of many species.

Assuming the average weight of a human is 100 lbs, or c. 50 kg (possibly a bit of an overestimate, as a good proportion of the population is children who weigh less than that), total human biomass is around 600 billion lbs (300 billion kg). That’s the number to beat.

Are you opening the door to plant species?

If so, then the biomass of wheat, rice and corn would each exceed the human biomass by a couple of orders of magnitude.

This site indicates that


Here they are talking about one species, Euphausia superba, and referring to metric tons (tonnes), or 150 billion kg per year. Note that this represents sustainable harvest, not total population, which of could be much larger. Anyway, Antarctic Krill as as species might at least be in the same ballpark as humans.

wooly, what is the basis for your statement? Do you have any figures on annual global harvest of those crops?