On April 5, 1877, American geneticist and physician Walter Stanborough Sutton was born. Sutton’s most significant contribution to present-day biology was his theory that the Mendelian laws of inheritance could be applied to chromosomes at the cellular level of living organisms. This is now known as the Boveri-Sutton chromosome theory. He furthermore provided the first conclusive evidence that chromosomes carry the units of inheritance and occur in distinct pairs.
“I may finally call attention to the probability that the association of paternal and maternal chromosomes in pairs and their subsequent separation during the reducing division as indicated above may constitute the physical basis of the Mendelian law of heredity.”
― Walter S. Sutton
Walter Sutton – Early Years
Walter Sutton studied engineering at the University of Kansas starting from 1896. However, after his younger brother died from typhus, Sutton changed subjects and decided to major in biology with a further enthusiasm for medicine. Sutton received both bachelor’s and master’s degree by 1901. For his masters thesis, he studied the spermatogenesis of Brachystola magna, a large grasshopper indigenous to the farmlands upon which Sutton was raised.
The Boveri-Sutton Chromosome Theory
Sutton moved to Columbia University in order to study zoology under Edmund Wilson. There, Walter Sutton managed to create his most influential works in the field of genetics: “On the morphology of the chromosome group in Brachystola magna” and “The chromosomes in heredity”. Back then, the German biologist Theodor Boveri also independently researched on the topic and came to the same conclusions at Walter Sutton. Therefore, the concepts both scientists discovered are now mostly referred to as the Boveri-Sutton chromosome theory.
The famous Boveri–Sutton chromosome theory unifies genetics which identify chromosomes as the carriers of genetic material. It explains the mechanism underlying the laws of Mendelian inheritance by identifying chromosomes with the paired factors (particles) required by Mendel’s laws. It also states that chromosomes are linear structures with genes located at specific sites called loci along them.
Thomas Morgan Hunt and William Bateson
Walter Sutton’s theory was accepted by many scientists and the continued work of Thomas Hunt Morgan at Columbia brought the theory to universal acceptance by 1915 through his studies of Drosophila melanogaster, the fruit fly, even as William Bateson continued to question the theory until 1921.[4,5]
However, Walter Sutton did not complete his PhD in zoology and returned to the Kansas oil fields for 2 years. Finally, his father directed him to return to his medical studies and he did so returning to Columbia University in 1905. Sutton obtained his doctorate in medicine in 1907. He started an internship at Roosevelt Hospital in New York working in the surgical division headed by Dr. Joseph Blake. Sutton further worked with the Surgical Research Laboratory at the College of Physicians and Surgeons. Walter Sutton became First Lieutenant in the United States Army Medical reserve Corps in 1911 and served at the American Ambulance Hospital outside Paris in 1915.
Within 2 months, he was surgeon-in-chief handling administrative duties in addition to his surgical responsibilities. His inventive aptitude was perhaps never more valued as he developed fluoroscopic techniques to identify and localize shrapnel within the soldier’s bodies and then removed the foreign items with instruments of his own design. After his return, he documented these techniques in Binnie’s Manual of Operative Surgery. Sutton’s return sailing from France was on June 26, 1915 having stayed only four months, but have made a significant contribution to wartime medical treatment.
William Sutton died rather unexpectedly at the age of 39 due to complications from acute appendicitis on November 10, 1916.
References and Further Reading:
-  100 Years Ago: Walter Sutton and the Chromosome Theory of Heredity
-  Walter Sutton at the Embryo Project
-  Walter Sutton at DNA from the Beginning
-  Thomas Hunt Morgan and the Chromosome Theory of Heredity, SciHi Blog, September 25, 2017.
-  William Bateson and the Study of Heredity, SciHi Blog, August 8, 2017.
-  Walter Sutton at Wikidata
-  Walter Sutton’s Chromosome Theory of Heredity: One Hundred Years Later
-  Chromosome Structure and Organization, Professor Dave Explains @ youtube
-  Ernest W. Crow and James F. Crow (January 1, 2002). “100 Years Ago: Walter Sutton and the Chromosome Theory of Heredity”. Genetics. 160 (1): 1–4.
-  S. R. Nelson; P. S. Nelson. “Walter Sutton’s Chromosome Theory of Heredity: One Hundred Years Later”. University of Kansas Medical Center.
-  Timeline of American Geneticists, via DBpedia and Wikidata