Show animal and plant species estimated to total about one and half million the total number of species of plants and animals known to exist is conservatively estimated at iaz 1 million according to a study of organic diversity issued by the columbia university press many new species are described every year and large additions may be expected in the future it is pointed out while the true extent of organic diversity can only be surmised at present there are known species of animals the number of described species of flowering plants is around and of lower plants these totals fall short of the actually existing number of species and do not take into account the variation which is commensurate only with the number of living individuals it is for centuries man has been interested te in the diversity of living beings being says dobzhansky professor of genetics in california institute of technology author of the study the multitude of the distinct kinds or species or organisms is seemingly endless and within a species no uniformity pro pre vai vails s in the case of man himself it is generally taken for granted that every individual is unique dif ferent from every other one who now lives or has lived the same is probably true for individuals of species other than man although our methods of observation are frequently inadequate to show this attempts to understand the causes and significance 0 of f organic diversity have been made ever since antiquity the problem se seems ems to possess an irresistible esthetic appeal and biology owes its existence in part to this appeal to |