Theodore Holmes Bullock

Theodore Holmes Bullock

Theodore Holmes “Ted” Bullock (16 May 1915 – 20 December 2005) is one of the founding fathers of neuroethology. During a career spanning nearly seven decades, this American academic was esteemed both as a pioneering and influential neuroscientist, examining the physiology and evolution of the nervous system across organizational levels, and as a champion of the comparative approach, studying species from nearly all major animal groups—coelenterates, annelids, arthropods, echinoderms, molluscs, and chordates.

Bullock discovered the pit organ in pit vipers and electroreceptors in weakly electric fish, as well as other electrosensory animals. His work on the jamming avoidance response in electric fish (work later carried on by Walter Heiligenberg) is an excellent example of how motor programs are integrated with incoming sensory information when generating a behavior pattern in response to a stimulus.

Bullock appealed to the scientific community to look beyond established paradigms in neuroscience, as well as to consider the ecology of an animal when endeavoring to understand its nervous system. As he once wrote, “Neuroscience is part of biology, more specifically of zoology, and it suffers tunnel vision unless continuous with ethology, ecology, and evolution”.

In his quest to go beyond a descriptive account of the nervous system, Bullock studied many different and unrelated, species. He believed that this “comparative approach” would reveal both general principles of the nervous system, and offer insights into which nervous system properties (anatomical, physiological, and chemical) were relevant to observed differences in species-specific traits, as well as which specific traits were relevant to observed differences in nervous systems. His resulting discoveries helped explain various properties of nervous systems. In one influential review he wrote, “Comparative neuroscience is likely to reach insights so novel as to constitute revolutions in understanding the structure, functions, ontogeny, and evolution of nervous systems. Without due consideration of the neural and behavioral correlates of differences between higher taxa and between closely related families, species, sexes, and stages, we cannot expect to understand nervous systems or ourselves”.

One colleague described Bullock as an “adventurous scientific explorer, continually seeking undiscovered phenomena and new unifying principles”. Until the very end of his life, at the age of 90, Bullock remained an active and influential presence in the fields of neuroscience and neuroethology.