Phylogeny of Arthropods and Economic importance of insects

Due to presence of a number of common characters, most of the biologists have grouped all the arthropods into one phylum. This necessitates a common origin from some ancestral group. This ancestor is thought to be an annelid which is more primitive than any living today. Occasionally arthropods and annelids have been grouped together into a single phylum, the Articulata.

Not all the biologists agree with this concept of a monophyletic origin for the arthropods. As many of them believe that most of the typical characters of the several major divisions of the phylum Arthropoda have arisen by convergent evolution. According to this view, many of the changes were made in these organisms as solutions to most of the problems associated with invasion on land. So these unrelated groups solved these problems in the same way and as a result their ancestral differences are almost completely masked by characters which seem to point wrongly to a single ancestor.

Within both schools of thought there are different theories;

o The onychophorans were probably derived from a lobopod annelid; the earliest onychophorans also gave rise to the Tardigrades.

„« Silk is a pasty secretion of the silk worm produced by the silk gland.

o The workers cause damage and feed on any thing edible which comes in their way.

Some topics in this essay:
HOUSE FLIES, ARTHROPODS Due, Insect Tachardia, LINE EVOLUTION, Trilobita Chelicerata, MEDICINAL VALUE, BED BUG, HUMAN HEALTH, MOTH Production, Tieg Manton, economic importance, insects damaging, „« lac, affecting human health, larval stage, insects affecting, line evolution, insects insects, sharov¡¦s theory, „« honey, alimentary canal, insects affecting human, 2 beneficial insects, sharov¡¦s theory 1966, 1 sharov¡¦s theory,