The social behavior of ants has been a central theme in the
research of Edward Wilson. Ants vary enormously in the size of their
colonies and the details of their social organization, but some
fundamental properties are shared by almost every ant society.
Let's illustrate these properties by using colonies of
Camponotus socius a beautiful sand-nesting species that occurs
in Florida and the southern parts of gulfcoast states.
The notorious Red Imported Fire Ant (Solenopis invicta),
the American South's "ant from hell," was accidentally introduced
into the port of Mobile, Alabama, sometime in the 1930's. Its native
range is northern Argentina and southern Brazil, and the first
immigrant colonies probably made their ways north as stowaways on
cargo ships. The species then spread throughout the southern United
States, where today its vast populations of fiercely stinging workers
make it a major pest.
colonies were found in 1942 by young Ed Wilson when he has 13 years
old (shown here with sweep net collecting insects). They were in
vacant lot next to his home near the Mobile docks. From his college
years onward, he used the fire ants as subjects for biological
studies. As a result, of this research and that of others, the fire
ant was one of the first species whose chemical communication system
was decoded, as described in the accompanying video.
Sociobiology is a relatively new discipline that has grown out of the study of creatures like leafcutter ants. It is broadly defined as the systematic study of the biological basis of social behavior in all kinds of organisms. By comparing the lives of ants with those of other social animals - as diverse as fishes, and the great apes - scientists have been able to develop a clearer picture of the way coordinated social groups arise in evolution.
In his book Sociobiology: The New Synthesis (1975), Wilson helped to create the new discipline. When he extended the same biological principles to human beings, however, the subject became far more complex and also controversial, due both to the powerful intervening role of culture and the sociopolitical ideas implicit in viewing heredity as a contributor to human nature.
approximately 10,000 known species of ants display among themselves a
dazzling array of physical types and modes of life.
The large eyes of tropical Asian Myrmoteras are used to help locate prey, which the huntress ant then capture with its unusual mandibles.
Little or nothing is known about many ants in both temperature and
tropical areas. Recurvidris, from tropical Asia, is not common, and
nothing is yet known about its social organization or diet.
The Museum of Comparative Zoology housed the largest and most nearly complete collections of ants in the world, comprising almost one million specimens representing at least 5,000 species. Specimens are kept in wooded "Cornell drawers" containing trays of ant specimens used in research. Each tray usually contains representatives of a different species.
Here, the first drawer contains examples of the enormous diversity from around the world. Drawer two contains samples of the over 100 ant species that occur in New England. Drawer three illustrates some of the many different lifestyles of New England ants.
Describing new species is a fundamental process in studying biodiversity. Ants are collected in the field using simple tools like those in the near by case. They are brought back to the Museum, and glued to triangles of stiff white paper, as in the fourth drawer. Labels are made and placed on each pin, linking the ants with the information recorded when they are collected (see drawer 5).
Thanks to the hard, almost imperishable nature of the outer chitinous skeleton of ants and other insects, the method is very efficient; many specimens preserved this way in the museum collection are over a hundred years old.
The newly collected specimens are then painstakingly compared to the other known species in the genus. If they differ significantly, they may be described as a new species. Representative specimens are carefully described, illustrated, and recognized rules. The name may describe the species, the region or habitat in which it occurs, or may name the new ant in honor of a person.
One ant is always chosen to be the Holotype (i.e. the specimen to which the new name is officially linked). Other specimens may be designated as "Paratypes". Type specimens provide permanent and authoritative documentation of species' characteristics and are therefore extremely valuable. The last drawer illustrates the look of type specimens resulting from the Pheidole project. The final step will be publishing the descriptions with the illustrations. No new name is valid until it is published. The illustration following are examples of new species described in .....( not recorded)
Museum collections are vital tools in biologist' effort to explore the earth's biodiversity by revising and extending the classification of the world's organisms. A typical ongoing study is illustrated here. With collaborator William L. Brown of Cornell University, Edward Wilson is currently reclassifying the enormous ant genus Pheidole in the Western Hemisphere. The two biologists have already defined over 600 species, of which 315 are new to science!
Here are some of the simple tools of the mymecologist (biologist who
specializes on ants) in the field. Not surprisingly, they include
trowels, bottles and forceps. Collecting tools are of three types.
Shovels, trowels, and axes are used to break into nests. The
aspirator (a simple lung-powered "vacuum cleaner") is used to pick up
ants as they run about. Specimens are then stored in vials containing
alcohol, and a field notebook is used to recorded important
information about each collection: locality, date, collector, habitat
and nest types.