The Last Extinction edited by Les Kaufman and Ken Mallory (MIT: $16.95; 186 pp.)

In as close to unanimity as you will find among scientists, those working in biology agree that a holocaust is overtaking the Earth’s wild creatures. A mass extinction of plant and animal species such as the world has not seen in tens of millions of years--if ever--is now well under way, and we are the cause of it.

There is nothing mysterious in this event: Humans are proceeding to blanket the habitable portions of the planet, appropriating ever greater portions of its energy and material resources for their own ends, and leaving assorted toxic byproducts in exchange. Such is the accelerating momentum of this phenomenon that nothing short of human catastrophe is likely to deflect it before most of the world’s menagerie is gone forever. For the relatively few people who are fully cognizant of this extinction and its implications, it is a tragedy beyond words. That understood, the rate at which the Earth is losing its billion-years’ legacy of biological diversity is still partially under our practicable control; it is to help stimulate effective conservation that Les Kaufman and Ken Mallory have assembled this collection of six essays.

David Jablonski, a University of Chicago paleontologist, summarizes what has been learned--much of it quite recently--about great extinctions in the past. At least five have occurred since Cambrian times in which 20% or more of all the Earth’s families of organisms recorded in the fossil record have been lost. One of these not only extirpated the dinosaurs but apparently permitted mammals to become the dominant vertebrates. James Williams and Ronald Nowack, of the U.S. Fish and Wildlife Service, annotate the extinctions that have taken place in North America since the arrival first of aboriginal man, and then Europeans. The great and infamous contemporary destruction of the Amazon tropical rain forest and its myriad life forms is discussed by Ghillean Prance.

This collection was not intended to be either a strident call to arms or a funeral dirge, and it is neither. The function of each essay is to point out realistic alternative conservation strategies that can work to preserve at least a portion of our living heritage. A rather disjointed--if intelligently written--compilation, “The Last Extinction” is only partially successful. But as educator Kaufman argues in his opening essay, those who care must use all available avenues. Else our descendants will surely despise us for the barren wreck we have bequeathed them . . . if they survive at all.