Introduction to Part IV

Introduction

Now that we’ve spent a fair amount of time and effort detailing the downside of our relationship with insects, it is time to turn to a discussion of the many, many ways in which insects benefit mankind.  It is true that some of those benefits come from insects’ capacity to cause considerable damage, such as when insects are used to inflict damage on an enemy.  But we will get that discussion out of the way quickly and go on to investigate the positive aspects of sharing the planet with insects.  Here, we will see that the benefits are broad, frequently unexpected, and often important to our ability to sustain the human population on planet earth.

It should come as no surprise that, considering the genetic plasticity of insects and the fact that they occupy every conceivable ecological niche imaginable, that the diversity of insect types will be an important consideration in this discussion.  Because there are so many types of insects, their ability to serve diverse functions in which humans might have an interest will come rapidly to the fore.  In this discussion, the ability of insects to help feed the human population (yes, humans still do eat insects—often on a voluntary basis!) will figure prominently.  Similarly, the fact that insects are excellent biochemists has not been overlooked by a variety of scientists looking for new human drugs or the means to produce new products with specific properties.  Insects have even provided us with the means to secure their own demise, knowledge of which has been appropriated and used by humans to control insects.  Other ecological functions that insects perform that have a demonstrated benefit to mankind include their production of a variety of defensive compounds, which humans have extracted and used to suit diverse ends.  And, it becomes abundantly clear every time there is a honey bee crisis, that the pollination activities of honey bees, as well as other insects, is vital to a healthy economy and our ability to grow food at a reasonable cost.  Of course, we would literally be up to our eyebrows in dead organic matter if we did not have insects carrying out the very important task of recycling biomatter on a global basis.  We are, in a word, indebted to insects whether we realize it or not.

Science itself owes a debt of gratitude to the phylum Insecta.  It is, perhaps, not surprising that those involved in experimental science have regularly turned to insects as experimental test models.  Indeed, this makes a good deal of sense both when we consider science in the past and in modern times.  Insects, after all, can be procured in large numbers, meaning that test subjects will be readily available, they are comparatively inexpensive to raise (particularly if the life cycle is known), and insects have physiological processes that are often good substitutes for vertebrate models.  In modern times, insects carry the ancillary benefit of not evoking the sympathies of animal rights groups, therefore it less likely to bring protesters to the door if insects rather than vertebrates are used for experimental purposes.

Because of their utility in the laboratory, insects have been widely used throughout Western science.  More notably, insects have contributed to some of the most important ideas upon which our understanding of the natural world is based.  Indeed, several important scientific theories, the ideas about which we are most certain in science, and which give us the ability to make testable predictions about unknown phenomena, owe their genesis to insects.  The Germ Theory of Disease, for example, came into being in part due to a disease that ravaged silk worm cultures in France.  Resolution of how the disease was transmitted cemented the Germ Theory of Disease in the scientific canon.  In biology, the joining of Darwin’s theory of evolution by means of natural selection with Watson and Crick’s elucidation of DNA’s ultrastructure was revolutionary and made possible by information coming from studies on insects.  How was this possible?  The source of the variation upon which natural selection acts comes to us from research done on an insect, Drosophila melanogaster.  The lowly fruit fly showed that mutations could be produced by irradiation and that mutation was the ultimate source of genetic variability upon which natural selection acts.

Four ideas came together to form the so-called Modern Synthesis that unified all biology.  These ideas were:

1. Organic chance in living organisms occurs over geological time by means of natural selection;

2. The mechanism of heredity was unveiled by Gregor Mendel;

3. Genetic variability arises via mutation which are retained in the genome and passed to offspring;

4. The three dimensional structure of DNA was described by Watson and Crick, which provided an explanation of how DNA can replicate itself with astonishing accuracy so that genetic information can be passed from parent to child.

These four elements came together in the Modern Synthesis to effectively unify all of biology.  It is the foundational idea in modern biology and it has enormous explanatory and predictive power.  Without insects, the Modern Synthesis would have taken much longer to come into being.  For all of these reasons, insects should command our respect and our attention.  We will give insects their due in Part IV.

Part IV cover photo credit:

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weeghdesign

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