What is a species? An often overlooked definition to most people. Webster’s online dictionary defines species as: a category of biological classification ranking immediately below the genus or subgenus, comprising related organisms or populations potentially capable of interbreeding, and being designated by a binomial that consists of the name of a genus followed by a Latin or latinized uncapitalized noun or adjective agreeing grammatically with the genus name (2) : an individual or kind belonging to a biological species. When in college my professors adjusted “capable of interbreeding” with capable of interbreeding and producing viable offspring”, meaning that the young produced were capable of breeding as well. There are many species capable of interbreeding, but the young are sterile. Therefore unable to reproduce and carry on the lineage. A good example of this is the mule, a hybrid between a male donkey and a female horse. This is why the mule is not considered a distinct species even though a male mule can produce viable offspring with a female horse.
Confused yet? Consider this: a Green Sunfish, Lepomis cyanellus, can readily mate and produce young with the Bluegill, Lepomis machrochirus. Although nearly all the young produced are male, some females are produced, and these females are capable of reproducing with the male hybrids (to the best of my research). By this definition these two distinct species should be considered a single species. Now obviously through genetics, we can see that these are two distinct genomes. But by the definition….
This leads to an interesting quandary doesn’t it? As the world of genetics becomes more and more involved with defining species, perhaps a new definition needs to be disseminated on a wider basis. Now that you are thoroughly confused, let’s examine whether or not the earth is gaining species as new species are discovered each year, or if the earth is losing species due to habitat destruction, global change, etc.
Depending on whose research you find most compelling, we are describing a variable number of new species each year. This `runs the gamut of bacteria through vertebrates. New species are discovered for a variety of reasons. The most common reasons are: 1. Genetics. As genomes are analyzed, species often considered a single species based on samples may be spilt often numerous times into multiple species. An Example of this that comes to mind is the field of Fish Tuberculosis. The number of Mycobacterium species being isolated has grown amazingly fast over the past decade. 2. New areas and habitats are recently opened to exploration. As politics change in the world, scientific exploration may be more viable and researchers may be allowed more readily into areas closed off from study. A recent example of this would be South East Asian areas such as Vietnam and Cambodia where there have been a recent explosion of new species being described. 3. Technological advances. For example, as new technologies allow us to explore deeper depths, and more harsh environments such as hydrothermal vents, new species seem to be popping up like Republican presidential candidates. Sorry, I couldn’t resist that analogy. 4. Historical collections are finally being cataloged. Thousands of biological samples sit waiting to be examined in University and museum cabinets and catacombs. Historically, explorers were very adept at collecting specimens, but not as thorough at sitting at a desk and counting fin rays of fish, or diagnosing minute details of plumage from a batch of birds that at a cursory glance all looked alike.
One of the more recent figures I have seen quoted gives a number of new species on average being around 15000 species a year. The vast majority of these are minute in size and do not usually warrant a huge press release to mass media. But there are new “large animals that come up as undiscovered even today. For example, the Elvis monkey, Rhinopithecus strykeri, was first described in 2010. At first glance, that seems like an amazingly unlikely discovery. But considering the diplomatic issues and remote location of S.E. Asia where these animals are found, as well as the lack of human intervention throughout the course of history in the area, a large animal can easily avoid the detection for the 250 plus years of active scientific endeavor describing life on earth. Similarly to the giant river rays of S.E. Asia that have only been in the world wide public consciousness courtesy of TV shows, it is likely that these monkeys were familiar to local peoples for generations.
No the “bad” news. A recent figure that has been floated shows the number of species we are losing to number on average more than 10000 species each year, and it is often quoted that this number could be much higher due to the number of undescribed species that remain to be “found”. Now, of course this number is also said to be increasing every year due to mankind’s influences on the earth and its habitats. Avoiding all the politics involved, I would feel comfortable making the argument that we lose 15000 species a year.
This puts us on an even plane based on the numbers. Assuming that my assumptions are correct. Now, the hard part to quantify, but the likely reality. The largest difference in the number of species gained and lost, based on the 15000 gained and 15000 lost is the number of vertebrate and higher invertebrate species we are losing. It is much more reported that higher vertebrate animals are being lost in greater numbers than microscopic or invertebrate animals. I’m not absolutely convinced one way or another but lean toward this conclusion. Just as we, as humans, are more likely to listen to a news report describing a new species of shark being discovered, rather than a new fruit fly species; we are on a whole more likely to shed a tear for a whale species disappearing rather than a bacterial species. That being said, I again feel comfortable despite this “fluffy” charismatic view mankind has toward life on earth saying that the number of vertebrate animals or larger invertebrate animals is reducing at a higher rate than microscopic life. Although I admit I might be swayed by my own “fluffiness”.
To add to your confusion, consider the number of once considered to be extinct species that have resurfaced such as the coelacanth, Latimeria spp. How do you protect a species that doesn’t exist? There is no protection afforded to extinct species. Or consider the number of Cryptids thought to exist. How do you protect a species that is considered by mainstream science to be dwelling in the realm of fairy tales or nightmares? Would it be illegal or even immoral to shoot and kill a Bigfoot child? Based on the modern theory that if Bigfoots exist, that they are Hominids and therefore our relatives, this is an interesting question. Especially when you look at Darwinian times when Bird shot was the primary indiscriminate method for collecting avian species for scientific studies and collections, and unfortunately still exists today. The modern classification of animals began with the Linnaean system of classification. I bet he never imagined a day when classification would be as confusing as it is, or could be based on all the factors we have to deal with in modern times.
So… Where does this discussion lead…. Hopefully soon you’ll find out on Natures Talk show. So tune in and find out. This sort of topic is what we are looking to do with a new show here on Natures Talk Show coming soon. Featuring Your truly as the host, Ray Owczarzak. Not giving too many details, but mark your calendars for upcoming Wednesday nights!
Article by Ray Owczarzak
Natures talk Show Host