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Scientists estimate that there are nearly 9 million species currently living on Earth and far less than a third of them have been identified. https://education

Scientists estimate that there are nearly 9 million species currently living on Earth and far less than a third of them have been identified. https://education.nationalgeographic.org/resource/biodiversity/ https://education.nationalgeographic.org/resource/biodiversi...

lupusreal 3y ago
How many of these unidentified species are animals scientists gave seen before, but previously considered to be members of another very closely related species? It seems like that is how most new species discoveries work; not the discovery of an animal never before seen but rather the discovery that one previously documented species is actually two species.
- TeMPOraL 3y ago
  Which calls into question the actual point. Perhaps species as a category is too fine-grained.
- iteratethis 3y ago
  A species' discovery is never about first "seen", it's first described. There's no way to know whom first saw it. Your assumption regarding splitting known species is wrong as it comes to numbers. It often happens for birds but this doesn't move the needle as there's only 10K birds. Almost every species on this planet is an arthropod and most are not described. It's trivially easy to "discover" new ones. Go to a bio-diverse area (say a jungle) and fill a wheelbarrow with soil. Filter the dirt and describe anything you find. It will take you forever but there will be dozens if not hundreds of "new" species. The main bottleneck is not finding them, it's describing them, which is very time consuming. Put some specialized lights up in the same area at night. One remote site I attended in Colombia discovered on average 20 new species of moth every single day. There's expected to be 150K moth species, which still may be an underestimation. And this doesn't even describe the truly tiny organisms living in soil and rivers and oceans. As it comes to species, the public has a bias for mammals and birds. Combined they're about 17-18K species only. Not even a drop in the ocean. You can split each of them into 10 separate species and this still doesn't do anything to inflate the total amount of species.
  - MattGaiser 3y ago
    Do you get to name ones you identify? Seems like a good tourist opportunity.
    - iteratethis 3y ago
      It's complicated. If you're a tourist and just stumbled upon a species not yet described, that's only the start. Next is a whole lot of work to actually describe it which a tourist would typically not be doing, so the idea that you should get naming credit is not a given. There's no hard rule for it. You can definitely give input for the name, and there's rules to naming. You can't name it after a company, for example. The most generous example I've seen is a research organization where you can "buy" a species name. Within taxonomy rules, you can decide on a name for a fee, even if you didn't discover the species at all. It's a way to fund research. In my experience though, getting an actual discovery described is the real issue. I've discovered both plants and insects new to science myself, did the work of collecting specimens and sending them to the correct authorities, but years later there's zero movement. Taxonomists are severely underfunded.
      - MattGaiser 3y ago
        > In my experience though, getting an actual discovery described is the real issue. I've discovered both plants and insects new to science myself, did the work of collecting specimens and sending them to the correct authorities, but years later there's zero movement. Taxonomists are severely underfunded. Ah, so wait, is there a central taxonomy office (or at least relatively centralized ones for different species groups) that is basically backlogged like a government passport office? Is that how it works?
        iteratethis 3y ago
        Unfortunately, that too is a mess. In a way, anybody can attempt to "add" a new species by describing it in a paper. So you'd typically send your specimen to the most fitting specialist willing and able to write that paper. The paper would then hopefully be reviewed by a naming authority. But a naming authority is just a bunch of people that got this authority by reputation. It's not the government. There may be regional authorities as well as multiple naming authorities for the same groups of species, not agreeing on species' status. All of this mess is then stitched together into a best-effort central database. Not even the categorization (so taxonomy levels) is singular, there's multiple systems. Species are constantly moved, split, merged.
pompino 3y ago
Its a mostly made-up number, until all of them are actually identified.
- bobbylarrybobby 3y ago
  It's made up, but definitely a better estimate than both 2^100 and the current number of known species. I imagine one way to obtain a coarse estimate would be fitting the number of known species over time to a curve like N-e^-kt curve and then using N as the estimate. Coarse, but not terrible if you can quantify the expected error.
  - pompino 3y ago
    People have come up with vastly different answers to this question. That to me heavily implies "i don't know" is the only right answer at this time. "Researchers have come up with wide-ranging estimates for how many species there are. As May points out, this ranges anywhere from 3 to well over 100 million – many orders of magnitude of difference. Some more recent studies estimate that this figure is as much as one trillion." https://ourworldindata.org/how-many-species-are-there https://ourworldindata.org/how-many-species-are-there
- bo1024 3y ago
  Of course any estimates that scientists make are "made up". But estimating the number of unseen species is a very old problem in statistics with a lot of rigorous research, including an important approach by Alan Turing. https://en.wikipedia.org/wiki/Unseen_species_problem https://en.wikipedia.org/wiki/Unseen_species_problem https://en.wikipedia.org/wiki/Good%E2%80%93Turing_frequency_estimation https://en.wikipedia.org/wiki/Good%E2%80%93Turing_frequency_... For intuition of how this is possible, imagine you sample k butterflies independently and all of them come from different species. By the birthday paradox, if there were less than k^2/2 different species, you would expect to see at least one pair from the same species, so you can estimate that there are more than k^2/2 different species.
  - deleted 3y ago
    [deleted]

lupusreal 3y ago

How many of these unidentified species are animals scientists gave seen before, but previously considered to be members of another very closely related species? It seems like that is how most new species discoveries work; not the discovery of an animal never before seen but rather the discovery that one previously documented species is actually two species.

TeMPOraL 3y ago
Which calls into question the actual point. Perhaps species as a category is too fine-grained.
iteratethis 3y ago
A species' discovery is never about first "seen", it's first described. There's no way to know whom first saw it. Your assumption regarding splitting known species is wrong as it comes to numbers. It often happens for birds but this doesn't move the needle as there's only 10K birds. Almost every species on this planet is an arthropod and most are not described. It's trivially easy to "discover" new ones. Go to a bio-diverse area (say a jungle) and fill a wheelbarrow with soil. Filter the dirt and describe anything you find. It will take you forever but there will be dozens if not hundreds of "new" species. The main bottleneck is not finding them, it's describing them, which is very time consuming. Put some specialized lights up in the same area at night. One remote site I attended in Colombia discovered on average 20 new species of moth every single day. There's expected to be 150K moth species, which still may be an underestimation. And this doesn't even describe the truly tiny organisms living in soil and rivers and oceans. As it comes to species, the public has a bias for mammals and birds. Combined they're about 17-18K species only. Not even a drop in the ocean. You can split each of them into 10 separate species and this still doesn't do anything to inflate the total amount of species.
- MattGaiser 3y ago
  Do you get to name ones you identify? Seems like a good tourist opportunity.
  - iteratethis 3y ago
    It's complicated. If you're a tourist and just stumbled upon a species not yet described, that's only the start. Next is a whole lot of work to actually describe it which a tourist would typically not be doing, so the idea that you should get naming credit is not a given. There's no hard rule for it. You can definitely give input for the name, and there's rules to naming. You can't name it after a company, for example. The most generous example I've seen is a research organization where you can "buy" a species name. Within taxonomy rules, you can decide on a name for a fee, even if you didn't discover the species at all. It's a way to fund research. In my experience though, getting an actual discovery described is the real issue. I've discovered both plants and insects new to science myself, did the work of collecting specimens and sending them to the correct authorities, but years later there's zero movement. Taxonomists are severely underfunded.
    - MattGaiser 3y ago
      > In my experience though, getting an actual discovery described is the real issue. I've discovered both plants and insects new to science myself, did the work of collecting specimens and sending them to the correct authorities, but years later there's zero movement. Taxonomists are severely underfunded. Ah, so wait, is there a central taxonomy office (or at least relatively centralized ones for different species groups) that is basically backlogged like a government passport office? Is that how it works?
      - iteratethis 3y ago
        Unfortunately, that too is a mess. In a way, anybody can attempt to "add" a new species by describing it in a paper. So you'd typically send your specimen to the most fitting specialist willing and able to write that paper. The paper would then hopefully be reviewed by a naming authority. But a naming authority is just a bunch of people that got this authority by reputation. It's not the government. There may be regional authorities as well as multiple naming authorities for the same groups of species, not agreeing on species' status. All of this mess is then stitched together into a best-effort central database. Not even the categorization (so taxonomy levels) is singular, there's multiple systems. Species are constantly moved, split, merged.

pompino 3y ago

Its a mostly made-up number, until all of them are actually identified.

bobbylarrybobby 3y ago
It's made up, but definitely a better estimate than both 2^100 and the current number of known species. I imagine one way to obtain a coarse estimate would be fitting the number of known species over time to a curve like N-e^-kt curve and then using N as the estimate. Coarse, but not terrible if you can quantify the expected error.
- pompino 3y ago
  People have come up with vastly different answers to this question. That to me heavily implies "i don't know" is the only right answer at this time. "Researchers have come up with wide-ranging estimates for how many species there are. As May points out, this ranges anywhere from 3 to well over 100 million – many orders of magnitude of difference. Some more recent studies estimate that this figure is as much as one trillion." https://ourworldindata.org/how-many-species-are-there https://ourworldindata.org/how-many-species-are-there
bo1024 3y ago
Of course any estimates that scientists make are "made up". But estimating the number of unseen species is a very old problem in statistics with a lot of rigorous research, including an important approach by Alan Turing. https://en.wikipedia.org/wiki/Unseen_species_problem https://en.wikipedia.org/wiki/Unseen_species_problem https://en.wikipedia.org/wiki/Good%E2%80%93Turing_frequency_estimation https://en.wikipedia.org/wiki/Good%E2%80%93Turing_frequency_... For intuition of how this is possible, imagine you sample k butterflies independently and all of them come from different species. By the birthday paradox, if there were less than k^2/2 different species, you would expect to see at least one pair from the same species, so you can estimate that there are more than k^2/2 different species.
- deleted 3y ago
  [deleted]