Posts Tagged ‘zoology’

15 January, 2013

Tuesday, January 15th, 2013

Hi Folks,

The middle of January it is, and it is COLD outside!  We have been having a stint of weather where the low temperatures have been bouncing around -5° F (-21° C).  That we have cold weather this time of year is not unusual  that it is this WARM is. In the bad (good?) old days, before global climate change, the period from about 15 January to 15 February gave us our coldest weather, and it often bottomed out below -40° F, C (both the F and C scales are the same at that lovely temperature).  The lowest temperature ever recorded in the lower 48 United States was –69.7°F (rounded off to –70°F)  or -56.5 °C at Rogers Pass, Montana  (web cam) which is about 120 miles, (193 km) from here on January 20, 1954. 

While it has gotten cold enough here in the last 10 to 15 years, it hasn’t been that cold, nor has it been cold for as long as it used to be. As much as I don’t like the concept – or the reality – of global warming, I have to say that warmer winters have become a blessing, particularly as I have gotten older.

Continuing a discussion of a few days ago when I mentioned being a member of a dying breed, those folks who could be called “Invertebrate Zoologists”, it is obvious that I am (we all are, but I suspect I am closer to the finish line of the race than are most of the reader of this esay) getting older and since immortality is not in the cards, the obvious end point is death.  So, I am dying – as we all are, it is part of living. 

However so, I think, is the “discipline” of “Invertebrate Zoology”. It is being killed by its own success. That is illustrated in an examination of the texts written in English.  In my first Invertebrate Zoology class, the text was the 2nd edition of Invertebrate Zoology, by Robert Barnes, published in 1968, with 743 pages.  Barnes updated and revised that text and after his  death, two other authors took over the task.  The most recent edition, the 7th, by Ruppert, Fox, and Barnes, was published in 2003, and had 1003 pages, and was very highly revised from the previous edition, and compared to the 2nd… wow!!!.

Kinorhynchs, such as this individual, live in sediments eating small organisms they find there.

Kinorhynchs, such as the individual imaged here, are invertebrates living in marine sediments eating small organisms they find there.

The 7th edition was the first concentrated less on the animals’ structures, and more on the evolutionary processes leading to the those animals and their structures.  The science of “Invertebrate Zoology” is really the comparative discussion of all animals, while the vertebrate chordates per se, are not discussed, there are many invertebrate chordates that are dealt with.  So, this is an holistic way of examining the entire animal kingdom. 

When you think about this process, however, it really is an impossible task – there are just too many types of animals and more to the point, it is exceptionally difficult to put them into a cohesive comparative framework.  The underlying principle of Invertebrate Zoology was that someone could learn enough of the basics about the major – and maybe some, or many of, the minor – animal groups, and could cogently discuss them in some manner.  This is a valid viewpoint, but it is probably only a valid viewpoint if there isn’t very much known about each group.  If there is a lot known, then the forest rapidly gets lost for the trees and generalities begin to become far too general.

During the middle part of the last century, the theorizing about invertebrates, indeed, all animals, and their relationships was dominated, in the English-speaking world, by the concepts of the coelom (the secondarily derived body cavity), segmentation, and embryonic development.  The bases for all of the theorization were put down in concise form in the six volume treatise, The Invertebrates, by L. H. Hyman.  Probably the greatest American zoologist of all time, Libbie Hyman defended some viewpoints and theories that, at the time, seemed very reasonable.  And even, if they didn’t seem right, her force of personality pretty much quashed all dissenting views.  During this period, Invertebrate Zoology seemed to be flourishing, but in actuality, it was stuck in a series of ruts.  Without any way to test the types of theories supported by Hyman – and, more or less – everybody else,  concerning evolution or functional anatomy, the science was basically descriptive.   There is nothing wrong with doing descriptive science, but it is only by hypothesis testing that science advances, and hypothesis testing was essentially impossible in Invertebrate Zoology at that time.

In the latter part of the 20th century things changed and changed fast. The techniques of cladistic analysis, comparative genomic analysis, biomechanics, functional morphology, and paleobiology allowed several whole new realms of biological interpretation. As a result, it suddenly (within a period of 20 years or so) became possible to erect an evolutionary “tree” for virtually any species, and phfft….. Most of the dogma of classical “Invertebrate Zoology” was found to be …. Wrong.  Not dead, as it had never really been alive, just simply wrong.

The Ruppert, Fox and Barnes Invertebrate Zoology text illustrates this very well as the concepts of phylum, coelom, and so and so forth are relegated to being useful – maybe – ways of grouping animals, but they are not anything that can be used as theoretical constructions. 

“Invertebrate Zoology” as thought of in the 1970s, has been replaced various disciplines concentrating on testing questions of ecology, evolution, embryonic development, and animal function using invertebrates as the test organisms. However, invertebrate zoology is still relevent, and has now become more of a blanket term that describes, the general type of animals a person might be working on rather than a cohesive discipline of scientific thought.  In this regard, invertebrate zoology has become a term more like physics or oceanography, sciences where the research is specialized much more on the “subdisciplines” such as astrophysics or chemical oceanography rather than on the overall category. So, as a “classically-trained” invertebrate zoologist, the scientific approach I initially learned has really died and been replaced by a much better, more dynamic and much more interesting approach.

More Later,