Bernard Kettlewell

Bernard Kettlewell

Bernard Kettlewell

Henry Bernard Davis Kettlewell (24 February 1907 – 11 May 1979) was a British lepidopterist and medical doctor, best known for his research on the peppered moth and its role in demonstrating natural selection in action.

Early Life and Education

Kettlewell was born in Howden, Yorkshire, England. He attended Charterhouse School and later studied medicine at Gonville and Caius College, Cambridge. After completing his medical degree, he worked as a physician but maintained a strong interest in entomology.

Career and Research

Kettlewell's most notable work was conducted in the 1950s when he collaborated with E.B. Ford at the University of Oxford. His research focused on the phenomenon of industrial melanism in the peppered moth, Biston betularia. This work provided compelling evidence for Darwinian evolution through natural selection.

Peppered Moth Experiment

Kettlewell conducted extensive field experiments in the English countryside, particularly in Birmingham and Dorset. He released both light and dark forms of the peppered moth and observed their survival rates in polluted and unpolluted environments. His findings showed that dark moths had a higher survival rate in polluted areas due to their camouflage against soot-darkened trees, while light moths thrived in cleaner environments.

Impact and Controversy

Kettlewell's experiments were initially celebrated as a clear demonstration of natural selection. However, later scrutiny and replication attempts led to some controversy regarding the methodology and interpretation of his results. Despite this, his work remains a cornerstone in the study of evolutionary biology.

Personal Life

Kettlewell was married to Christina Kettlewell, and they had two children. He continued to work in both medicine and entomology until his death in 1979.

Legacy

Kettlewell's research on the peppered moth is still widely cited in textbooks and scientific literature as a classic example of natural selection. His work has inspired further studies in the field of evolutionary genetics and population biology.

See Also

• Natural selection
• Industrial melanism
• Peppered moth evolution
• E.B. Ford
• Evolutionary biology