350,000 Species of ...

[Colibri]

@Keeve

That’s what I was hoping to hear. Without genetics, I’d love to know how to tell the difference between a whole new species as opposedto variations within a species.

Of course, if you find them in breeding condition in the same place at the same time, and there are consistent and non-overlapping differences between them (no matter how small) then they are almost certainly different species.

The only time there is a problem (if you are using the biological species concept) is if you have somewhat different populations living in different places that are not in contact. In this case, you cannot definitively determine if they would interbreed of they were in contact.

In practice, what is done is to evaluate the degree of difference (especially in characters related to courtship and breeding) relative to other pairs of related species that are known to be non-interbreeding. And the degree of difference that is acceptable to consider them different will differ according to group, as will the characters considered. For example, in Birds-of-Paradise one might look at differences in the elaborate plumes used in courtship display. In flycatchers, in which many species look very similar, you would consider differences in call.

In many insects and other animals, the male genitalia differ in form between species. In this case, you could be sure the forms couldn’t successfully mate even if they were not in contact.

Ditto. But I hear about new species so often, from so many sources, that I’m very curious (and a bit suspicious) about how the whole process works.

There are so many undescribed species out there, at least in insects and smaller groups of animals, you shouldn’t be surprised at all to hear about new ones. We’re only just scratching the surface after 200 years of cataloging.

If you were an extraterrestrial, cataloguing the species of this galaxy, how would you consider the many types of humans on this planet? Would ETs consider the Scandinavian Blondhead and the Australian Aborigine to be one species or two? Heck, I live here, and without genetics (i.e., ability to produce fertile offspring), I don’t know why we would consider a Chihuahua and a St. Bernard to be in the same species.

Those are both extremely unusual cases. Modern humans are more widespread than almost any other species. However, how an extraterrestrial would catalog human populations would depend on how thoroughly they had sampled them. In the 19th century, distant populations of many widespread populations of animals were classified as separate species. As scientists collected in the regions in between, they realized there were intermediates and they were the same species.

Back in the early to mid 20th century, there was a period of lumping when taxonomists combined many formerly separate species. Now, however, due to genetics, it appears that this lumping went too far, and many species are being re-split because genetic studies indicate that they do not interbreed.

Dogs are really much more variable than virtually any other animal species, but this is maintained by artificial selection and not a good example to evaluate typical species differences on.

[Colibri]

@Fotheringay-Phipps

I meant in the course of establishing 350,000 species, you would need to look at millions and millions in aggregate, not that you need that many for each species.

True, but as has been pointed out, that has been accomplished by thousands of people over several centuries. However, the Smithsonian Institution alone has about 83 million biological specimens, including 35 million specimens of insects. The American Museum of Natural History in New York has over 1 million specimens of birds, including 99% of all known species.

What would you think are the total man-hours involved in documenting a single species, including field observations, study, research, write-up etc.?

Hard to say. We found our new bird species while conducting a much larger study over the course of five months. Do you count the five months we spent in the field, or just the time that was spent collecting and preparing the specimens, which was a matter of hours? I would guess the analysis and writing up probably took a matter of several person-months on the part of the five authors combined.

Often it’s a combined effort, in which one person has collected the specimens and done the field work, while someone else has done the research in the collections.

It would seem from what you describe and the sheer number of species out there that a significant percentage of the world’s resources must be going into just documenting and keeping track of various species. (This suggests a possible solution to the current economic crisis … :D)

Absolutely not. There is currently a total of 4786 taxonomists (for all groups of organisms) listed in the World Taxonomist Database, a trivial number considering the vast numbers of undescribed species. Taxonomy these days is not a particularly popular field, and is greatly underfunded. About 2000 insect species are named in a good year. Assuming there are 5 million species of insects in total (and there may be many more), and something like 1 milllion known insects, at this rate it will take more than 2,000 years to name them all.

[Colibri]

@Lemur866

If you study mammals or birds then a new species is tremendously exciting. But if you study insects new species are so common that it is impossible for one person to keep up. They’re as common as dirt, anyone who has the time and funding can go to any tropical rainforest and come up with dozens of new species of insects.

Exactly. If I were looking at a diverse but little-studied group like mites, I could probably quite easily find new species within a 20 minute drive from my house, if I could get somebody to describe them. If I did an expedition to some of the less studied mountain ranges of Panama, I would be sure to collect dozens of new species of insects and a number of plants.

A few years ago I went out to a small offshore island in Panama to study birds. I saw an interesting beetle and brought it back to show my entomologist friend. He said it was probably new (it didn’t match any species he was familiar with) but he wasn’t going to describe a new species from just a single specimen.

[Polycarp]

Given the cladistic definition of what larger group birds fit into, there’s something eerie about the idea of a SDMB moderator going to a Panamanian offshore island to study, uh, … How closely do you resemble Sam Neill, anyway?

[Colibri]

@Polycarp

Given the cladistic definition of what larger group birds fit into, there’s something eerie about the idea of a SDMB moderator going to a Panamanian offshore island to study, uh, … How closely do you resemble Sam Neill, anyway?

Since you mention it, this is a picture taken on my last field trip.

[Fotheringay-Phipps]

@Colibri

Hard to say. We found our new bird species while conducting a much larger study over the course of five months. Do you count the five months we spent in the field, or just the time that was spent collecting and preparing the specimens, which was a matter of hours? I would guess the analysis and writing up probably took a matter of several person-months on the part of the five authors combined.

Often it’s a combined effort, in which one person has collected the specimens and done the field work, while someone else has done the research in the collections.

But if you apply that to beetles, it seems hardly possible that all that work has been done, multiplied by 350,000, even over 200 years (& I would have to imagine that much more of the work has been done recently).

Absolutely not. There is currently a total of 4786 taxonomists (for all groups of organisms) listed in the World Taxonomist Database, a trivial number considering the vast numbers of undescribed species. Taxonomy these days is not a particularly popular field, and is greatly underfunded. About 2000 insect species are named in a good year. Assuming there are 5 million species of insects in total (and there may be many more), and something like 1 milllion known insects, at this rate it will take more than 2,000 years to name them all.

What does this mean? There are 350,000 species of beetles but they are not yet named? How does anyone figure out which are being referred to? Do they have numbers? If they have been identified and described but just haven’t yet been named, then the major work has been done.

I imagine I’m just not understanding you here.

I saw an interesting beetle and brought it back to show my entomologist friend. He said it was probably new (it didn’t match any species he was familiar with) but he wasn’t going to describe a new species from just a single specimen.

Is he familiar with all 350,000 known species? Or did he look them up in a database?

From the totality of your remarks, it begins to seem as if there are not actually all this many known species, but I wonder if you could clarify this some more.

[Smeghead]

@Fotheringay-Phipps

Is he familiar with all 350,000 known species? Or did he look them up in a database?

I’ll tackle this little bit. An expert doesn’t need to do that. There’s not just one big lump labeled “beetles”. The beetles are divided up into families, subfamilies, genera, etc. Someone who knows what he’s looking at could, and I’m just speculating here, immediately eliminate 99.9% of the possibilities and say, “Oh, that obviously belongs to the Cecil group, of which there are fifteen known members, and it doesn’t look like any of those,” if not off the top of his head, with a minimum of research.

[Duhkecco]

I was wondering about a database of all known species and came across this:

WASHINGTON (May 9, 2007) – Many of the world’s leading scientific institutions today announced the launch of the Encyclopedia of Life, an unprecedented global effort to document all 1.8 million named species of animals, plants, and other forms of life on Earth. For the first time in the history of the planet, scientists, students, and citizens will have multi-media access to all known living species, even those that have just been discovered.

The Field Museum of Natural History, Harvard University, Marine Biological Laboratory, Smithsonian Institution, and Biodiversity Heritage Library joined together to initiate the project, bringing together species and software experts from across the world. The Missouri Botanical Garden has become a full partner, and discussions are taking place this week with leaders of the new Atlas of Living Australia. The Encyclopedia today also announced the initial membership of its Institutional Council, which spans the globe, and whose members will play key roles in realizing this immense project.

http://www.eol.org/content/page/press_2007_5_9.

Old news for some, but new to me.

[slaphead]

@Fotheringay-Phipps

But if you apply that to beetles, it seems hardly possible that all that work has been done, multiplied by 350,000, even over 200 years (& I would have to imagine that much more of the work has been done recently).

It seems eminently possible to me. Bear in mind that the whole classification effort would have started out with “Beetles found on my doorstep” by A Beetle Obsessive With A Private Income, back in the days when most of the administrative cruft of academia did not exist. Technology these days is a lot better, but it’s no longer possible to score a bundle of new species by strolling from your Cambridge college down to the banks of the Cam with a net and some jars, and then write them all up in a weekend.

[Giles]

350,000 over 200 years is about 2,000 per year, or 40 per week. That seems to me to a do-able even with a relatively low number of entomologists working in the field. One part that would take up a lot of time would be thinking of the species names. (“Right, the most distinctive thing about this one is the green legs – what’s the Latin for ‘green legs’?”)

[Polycarp]

@Giles

350,000 over 200 years is about 2,000 per year, or 40 per week. That seems to me to a do-able even with a relatively low number of entomologists working in the field. One part that would take up a lot of time would be thinking of the species names. (“Right, the most distinctive thing about this one is the green legs – what’s the Latin for ‘green legs’?”)

A good scientific description gives full data for defining the species – including but not limited to how it differs from related but distinct species. You would have to demonstrate that these beetles have the distinctive mouth parts and ridge at the front of the carapace characteristic of genus Xanthomandibulatius, but differs from the three named species in that genus in the following six characteristics, including the green legs that you’ve chosen as the most obvious difference, and named the species chlorotarsus in consequence. (Hypotherical names invented for the occasion.)

Also, Colibri’s point about the fuzziness of species is quite important. There are three distinct species of Zebra, one of which formerly included the now-extinct Quagga as a subspecies – and what distinguishes them is not obvious to the untrained eye.

This gets even more problematical in paleontology, with its lumpers and splitters, as I learned in the Nineties while Barb was going for her concentration in paleoanth. A thoroughgoing lumper would have classed the species known at that time into two genera and six speices: Homo sapiens, H. erectus, and H. habilis, and Australopithecus africanus, A. boisei, and A. robustus. A splitter would have had a dozen species in at least three genera – all working with the same data, but interpreting the degree of difference between the fossil finds expansively or narrowly. (I’m specifying then because I have no expertise on the more recent finds.)

The same sort of thing is the reason behind Brontosaurus being dropped in favor of Apatosaurus – the latter name was given first to a species that the type specimen of Bronto proved to be in the same genus with.

By the way, I found out only recently that Eohippus is back – the name, I mean. Studfies of the species of Hyracotherium, the primitive perissodactyl that Eohippus was for a long time the junior synonym of, proved that the type for Hyracotherium was a paleothere, a relatively short-lived family of primitive dawn-horse-like browsers, but the species that had been the type for Eohippus was a primitive horse, there4fore bringing Eohippus back out of synonymy as the proper genus name. IMO, poetic justice.

[Colibri]

@Fotheringay-Phipps

But if you apply that to beetles, it seems hardly possible that all that work has been done, multiplied by 350,000, even over 200 years (& I would have to imagine that much more of the work has been done recently).

Upthread I gave a cite of approximately 2000 beetle species described a year. This appears to be a better cite, and gives an average rate of 3,154 species of beetle described per year since 1978. At that rate, it would take 111 years to describe 350,000 species. (The link actually estimates that there are 400,000 known species, which would take 127 years.) Binomial nomenclature has been around for about 250 years, since Linneaus (1758). Even assuming that the rate was slower in the past, the available time is ample to account for all the described species.

What does this mean? There are 350,000 species of beetles but they are not yet named? How does anyone figure out which are being referred to? Do they have numbers? If they have been identified and described but just haven’t yet been named, then the major work has been done.

I imagine I’m just not understanding you here.

I already explained in the first line of my first post in this thread that the figure of 350,000 beetle species refers to those species that have already been described and given a scientific name. The figure is an estimate because scientists may disagree whether some forms are separate species or just subspecies of a single species, some species may have inadvertently been named twice (or more), different species concepts may have been applied by different taxonomists, and so forth.

The link above estimates that besides the already known, described, and named species of beetles, there may be an additional 2 million that have not yet received a name.

Is he familiar with all 350,000 known species? Or did he look them up in a database?

No. As has been explained, an entomologist can usually tell what family, subfamily, or even genus an unknown species belongs to, often by using keys to group characteristics. Then he or she can look up what the characteristics of the known species are, and determine that the unknown species doesn’t fit any of the known species.

My friend is a specialist on weevils, especially the weevils of Panama. He has a good idea of what species are already known from Panama, and from the region, and tell if something is likely to be new.

In the case of some of the undescribed species he showed me, he said a specialist had looked at the collection several years ago, and set those specimens aside because she didn’t recognize them as belonging to any known species in that particular group. More study would be needed to determine if they certainly were new, but there was a good chance they were.

From the totality of your remarks, it begins to seem as if there are not actually all this many known species, but I wonder if you could clarify this some more.

I am not sure where you are getting the idea that there are not “all this many known species” from my remarks. Most references give a figure of at least 350,000 known species of beetles, while the one I cited above (probably more up to date) says 400,000.

[Colibri]

@Colibri

My friend is a specialist on weevils, especially the weevils of Panama. He has a good idea of what species are already known from Panama, and from the region, and tell if something is likely to be new.

To elaborate on this a little more, in the case of the specimen I brought to him from the island, he recognized it as being similar to a known species that occurs on the mainland. However, it differed sufficiently to indicate to to him that it was probably a different species. More specimens would be needed to be sure, however. Unique species often evolve on islands isolated from the mainland. This particular island, for example, has four endemic species of vertebrates, including a Pygmy Three-toed Sloth.

Even I, who am not a specialist, can easily recognize the major families of beetles, such as weevils, scarabs, long-horned beetles, ground beetles, tiger beetles, cerambycids, etc. If I had the right reference, I could probably key something out to the right genus. There would be no more need to compare an unknown species of beetle to all 350,000 known species than to compare an unknown species of bat to all species of mammals, including hippos, whales, or tigers. Once you have it to family you have narrowed it down a lot, and families are mostly easy to recognize even for the non-specialist.