Debunking a myth about sperm's DNA.

Friderun Ankel-Simons and Jim M. Cummins have a biology lesson they think evolutionary biologists should learn. The pair recently chastised fellow scientists for what they contend is a widespread misconception-that one kind of paternal DNA, mitochondrial DNA (mtDNA), does not get into the egg when the sperm fertilizes it.

"How this assumption has spread is startling. It's a scandal because it mis- represents a biological fact," says Ankel-Simons of the Duke University Primate Center in Durham, N.C.

Mitochondrial DNA, which sits inside the energy-producing organelles called mitochondria that roam outside a cell's nucleus, has been a useful tool for evolutionary biologists because many studies have shown that it is inherited only from the mother. For example, mtDNA analysis is at the heart of the con- troversial African Eve hypothesis, which traces human origins to a single woman in Africa (SN: 9/25/93, p. 196).

In the Nov. 26 Proceedings of the National Academy of Sciences, Ankel-Simons and Cummins, a researcher at Murdoch University in Australia, point out that evolutionary biologists almost invariably claim in their research articles and popular books that the paternal mtDNA is not inherited because the sperm's midpiece and tail, where the DNA is located, do not enter the egg. That's false, say the two researchers: Microscopy and DNA analysis show that mtDNA from the sperm's midpiece does appear in the fertilized mammalian egg.

Andrew Merriwether, an evolutionary biologist at the University of Michigan in Ann Arbor, notes that the reasons for maternal-only mtDNA inheritance are unclear and concedes that some of his colleagues may not explain this accurately. Nevertheless, studies have established that paternal mtDNA is so rarely transmitted to offspring that mtDNA analyses remain valid, he says.

"It may get in the egg but it doesn't stay there."

Books

The American Horticultural Society Pruning and Training: A Fully Illustrated Plant-by-Plant Manual-Christopher Brickell and David Joyce. This remarkably thorough guidebook provides basic techniques for training plants at all stages of life and gives specific information about pruning and managing more than 800 trees, shrubs, roses, fruits, and climbing plants. Opening chapters explain how plants grow and the various tools used for exploiting growth habits. A plethora of color photos and drawings illustrates techniques. Dorling Kindersley, 1996, 336 p., color photos and illus., hardcover, $34.95. The Dayhiker's Handbook: An All-Terrain, All-Season Guide-John Long and Michael Hodgson. This unique guide blends useful, how-to knowledge with anec- dotes about the authors' hiking adventures. It spans the realm of hiking over terrain ranging from jungle to wilderness, desert to waterway. Readers learn how to walk, what to eat and wear, how to navigate, and how to fend off danger, and can enjoy essays about the joys of solitary hiking as well as more practical considerations such as the downside of quicksand. McGraw, 1996, 216 p., b&w photos and illus., paperback, $14.95.

The Eleventh Plague: The Politics of Biological and Chemical Warfare-Leonard A. Cole. In Tokyo, 5,500 people on a subway are victims of the nerve agent sarin. Residents of San Francisco fall ill with an infection by a bacterium called Serratia marcescens. The first instance is an act of terrorism; the second is a result of a test conducted by the army. These are just two examples that Cole, a political scientist, puts forth in an examination of the threats of chemical and biological warfare. WH Freeman, 1997, 284 p., hardcover, $22.95.

The Essential Guide to Prescription Drugs 1997: Everything You Need to Know for Safe Drug Use-James J. Rybacki and James W. Long. This encyclopedia fea- tures more than 300 generic and 2,000 brand-name prescription drugs, each listed alphabetically by generic name. Profiles contain at least 45 categories of information, including side effects, precautions, and effects of dis-continuation. Other chapters outline new medicines and feature a host of tables and a glossary. HarpPL, 1996, 1,156 p., color plates, paperback, $20.00.

HAL's Legacy: 2001's Computer As Dream and Reality-David G. Stork, ed. Created 30 years ago by Arthur C. Clarke and Stanley Kubrick for the movie 2001: A Space Odyssey, the famous science fiction computer HAL celebrated its "birth" on Jan. 12, 1997. This tribute to HAL describes the state of computer science relative to HAL's prophecy of machines that lip-read, recognize and synthesize speech, reason, and interact with humans. Contributors are Rosalind Picard, Murray Campbell, and others who evaluate the feasibility and state of artifi-cial intelligence. MIT Pr, 1997, 384 p., color and b&w photos, hardcover, $22.50.

The Infamous Boundary: Seven Decades of Heresy in Quantum Physics-David Wick. In 1927, physicists Max Born and Werner Heisenberg declared, "Quantum mechanics is a complete theory; its basic physical and mathematical hypotheses are not further susceptible to modification." Since quantum mechanics is the theory that describes the behavior of fundamental particles, its synthesis was indeed a "victory over the unruly atom." But other physicists immediately dis-puted this conclusion. Einstein and some others began a debate that continued to their deaths, and while most physicists today accept quantum mechanics as the basis of their discipline, heretics make their voices heard regularly and sometimes persuasively. Wick surveys these arguments in clear text largely free of equations saved, which are for appendices. Originally published in hardcover in 1995. Copernicus, 1996, 310 p., b&w illus., paperback, $19.00. An Inordinate Fondness for Beetles-Arthur V. Evans and Charles L. Bellamy.

Known to inhabit nearly every biological niche from the frigid polar regions to the canopy of the tropical rain forest, beetles account for one of every five species of animals and plants combined, making them the most successful creatures on the planet. In ancient Egypt, dung-rolling scarabs were representative of the invisible forces that moved the sun across the sky in a geocentric universe. What makes these animals so persistent in nature and prevalent in history? This adoring tribute to beetles seeks to answer that question as myriad Coleoptera are dissected and chronicled throughout their 250-million-year history. H Holt & Co., 1996, 208 p., color photos, hardcover, $40.00.