Monday, August 5, 2013

The Limited Male

Mating Butterflies

The fundamental role of the male in biology is to ensure greater diversity of characteristics within the genetic pool of a species population.  The broader the range of capabilities within a group, the more likely some individuals will survive whatever calamity confronts them.  Some individuals are better adapted to handle drought.  Others can better survive extreme cold.  Some characteristics make for better predators.  Some organisms exhibit greater resistance to specific diseases.    

There need not be an unusual stress placed on a species for genetic diversity to play its role in selecting a population’s most capable individuals.  Each generation provides more offspring than the environment can sustain.  Many are typically lost to predation and accident.  Age related factors cause the death of older individuals in the species.  Dominant individuals stake out more abundant territories as their own, leaving marginal areas to less competitive animals.  Poor nutrition may lead to their death or their genetic characteristics may not continue because they were simply unsuccessful in raising a family.  Each species’ generation faces these tests in good times and bad.  The more severe the tests the greater the pressures placed on the population and the more stringent are the selection processes to determine which individuals live to reproduce offspring.   Distressed populations either select individuals suited to the changing circumstance or suffer extinction. 

The role of the male in some species may extend beyond being a mechanism to ensure genetic diversity.  In a number of vertebrate species the male has an important part in raising the young.  Among animals that live in herds only a select few males may be allowed to mate with the females, insuring the characteristics of only the most dominant among the male population are represented in subsequent generations.  These factors are those of organisms that may live several years and behavior is an important part of staying alive.  Among many invertebrate species, such as insects, conscious behavioral choices are less likely to be a governing factor in determining individual survival.  There are at least two significant reasons for this.  The more obvious of the two is that an insect has little room for a brain.  There is a central processing point for its nervous system that is located in the head but its ability for complex thought is severely constrained by its tiny size.

Insect survival strategy has less to do with individual capabilities and more to do with numbers.  Female insects are often capable of producing eggs by the hundreds, if not thousands.  The vast majority of these offspring will not live to reproduce.  They are near the bottom of the food chain and provide themselves as food at all stages of their life cycle.  Only a few need survive to maintain a healthy species’ population.  Still, it requires an enormous amount of protein in the female’s diet to manufacture all those eggs.  Once the male has copulated with the female and played his part in genetic recombination there is little left for him to do that will enhance the survival of the species.  If the insect is predacious he can serve as a convenient meal for the female, going a long way towards meeting her needs in egg production.  Once the seduction is accomplished she bits off his head and then devours a magnificent lunch.

The role of males among most insects in determining species survival beyond fertilization is negligible.  In many species they represent only a small proportion of the actual population.  It is among the vertebrates where behavior is often more elaborate that the male's role becomes significant.  Here the young are relatively few and often require the assistance of both parents to survive.  A single parent, as is the case with many birds, isn't enough to procure food for its demanding young.  The benefit of the male beyond the role of genetic recombination can remain obscure, even in more complex organisms.  They can be unreliable when it comes to aiding their young.  Yet the vital component of maintaining species diversity is enough to insure that sexual reproduction has radiated out to include all higher forms of life.  The male has evolved into a distinctly separate role from that of the female.  The advantages of a male presence in a number of species may be debatable but, on the whole, appears to make for a curious partnership of the sexes.  It certainly has become the focus of concern among human couples, at the dinner table and in bed.

Biology Topics:


Eukaryotic Cell

Protein Creation

Living - Why?

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