An Inspiring Journey - Bill Neaves’ Lifelong Study of Reptiles

By Patrick Regan

Leaning forward, fixing his eyes on a seven-inch lizard skittering across the sand at the bottom of a blue kiddie pool, Stowers President Emeritus William (Bill) Neaves, PhD, asks, "So, this is neotigris?" The lab tech at the Stowers Institute's reptile facility confirms his presumption. "That's a male tigris crossed with an all-female species, neomexicanus," Neaves declares with unabashed excitement. "What striking animals. I need to come back and take some photos."

The colony of 800 whiptail lizards at the Stowers Reptile & Aquatics Facility is one that Neaves could only have dreamed of when he began his research career nearly fifty years ago. His boyhood fascination with lizards never abated, and as a young man his interest came to focus on several species of whiptail lizards native to the American Southwest and northern Mexico. So strong was that interest, in fact, that it would reset the course of Neaves' career.

Having earned an undergraduate degree in biology, Neaves began medical school at Harvard in 1966 with the notion of eventually returning to his West Texas hometown of Spur to practice medicine. By the mid-1960s papers appeared reporting the unusual chromosomal characteristics of certain whiptail species. Neaves had first learned of the high probability of an all-female species while working as a National Science Foundation summer fellow in the Chihuahuan Desert in 1964. He was determined to know more.

In the summer of 1967, he and his young wife, Priscilla, packed up their Volkswagen camper van and set out for Alamogordo, NM, to collect lizards. At the end of one long day of collecting, Neaves noticed a lizard with an uncharacteristic intense blue coloration on its tail and abdomen. As analysis would later prove, he had captured a previously unknown hybrid tetraploid, a healthy lizard with four sets of chromosomes.

That autumn, Neaves returned to Harvard, but not medical school. Instead, he began working toward a PhD in anatomy, writing his dissertation on the reproductive biology and evolution of lizards. In 1968, the journal Science published Neaves' first lizard-related paper exploring mating between different lizard species and parthenogenesis (unisexual reproduction) among whiptails. A second Science paper on gene dosage in triploid lizards followed a year later. In 1971, the journal of Harvard's Museum of Comparative Zoology, Breviora, published Neaves' findings on the tetraploid hybrid and his speculation about the genetic mechanism of parthenogenesis.

After a two-year Rockefeller Fellowship as a lecturer in veterinary anatomy at the University of Nairobi, Neaves moved back to Texas as an assistant professor of cell biology at the University of Texas Southwestern Medical Center. In the years that followed, Neaves was drawn into academic administration, first serving as dean of Southwestern's graduate school and later becoming medical school dean, a post that, regrettably, left little time for research.

Back then, Neaves had a dream he kept largely to himself. In his retirement, he imagined resuming his doctoral research — building open-air lizard pens out on the old family homestead and conducting whiptail breeding experiments. In early 2000, Neaves agreed to serve as the founding president and CEO of the Stowers Institute, a decision which made his longstanding dream seem unlikely to be realized.

Standing amidst a sea of blue kiddie pools in the reptile facility, Neaves marvels at his good fortune. The whiptail colony—by far the largest colony in the world—was initially formed in 2003 when Peter Baumann, PhD, now an investigator of both the Stowers Institute and Howard Hughes Medical Institute, decided to pick up where Neaves' work left off decades ago. A 2010 Nature paper coauthored with other Stowers colleagues resolved the chromosomal mechanism of parthenogenesis. The following year, a Proceedings of the National Academy of Sciences paper reported the successful synthesis of the tetraploid as a self-sustaining lineage.

In December 2014, a report published in Breviora—forty-three years after Neaves' own Breviora paper detailed his discovery of a tetraploid hybrid in New Mexico—took matters to a logical conclusion. The paper announced and taxonomically described a new species, Aspidoscelis neavesi, Neaves' Whiptail Lizard.

A half-century after the whiptail first captured his imagination, Neaves' "lizard adventure" is far from over. He anxiously awaits genome sequencing results with full expectation that they will further unravel the mysteries of these extraordinary and enduringly captivating little creatures.