Cavalier-Smith

Thomas Cavalier-Smith

Born	October 21, 1942
Birth place	London, England
Died	March 19, 2021
Nationality	British
Known for	Classification of life, endosymbiotic theory

Thomas Cavalier-Smith (October 21, 1942 – March 19, 2021) was a British evolutionary biologist known for his work on the classification of life and the endosymbiotic theory. He made significant contributions to the understanding of the evolutionary relationships among living organisms and proposed several new taxonomic groups.

Early Life and Education

Cavalier-Smith was born in London, England. He attended the University of Cambridge, where he completed his undergraduate studies in natural sciences. He later pursued a Ph.D. in cell biology, focusing on the structure and function of cell membranes.

Academic Career

Cavalier-Smith held academic positions at the University of Oxford and the University of British Columbia. Throughout his career, he was known for his innovative ideas and challenging the traditional views of biological classification.

Contributions to Biology

Cavalier-Smith is best known for his work on the classification of life. He proposed the division of life into six kingdoms, which included the traditional kingdoms of animals, plants, and fungi, as well as three additional kingdoms: Protozoa, Chromista, and Bacteria. His classification system was based on the complexity of cellular organization and the presence of certain cellular structures.

Endosymbiotic Theory

Cavalier-Smith also contributed to the endosymbiotic theory, which explains the origin of eukaryotic cells as a result of symbiotic relationships between different species of prokaryotes. He proposed that mitochondria and chloroplasts, organelles found in eukaryotic cells, originated from free-living bacteria that were engulfed by ancestral eukaryotic cells.

Chromalveolata Hypothesis

One of Cavalier-Smith's notable hypotheses was the Chromalveolata hypothesis, which suggested that a large group of eukaryotic organisms, including algae and protozoa, shared a common ancestor that acquired chloroplasts through secondary endosymbiosis.

Legacy

Cavalier-Smith's work has had a lasting impact on the field of evolutionary biology. His ideas have influenced the way scientists think about the tree of life and the evolutionary relationships among different groups of organisms. Although some of his hypotheses remain controversial, they have sparked significant research and debate in the scientific community.

Also see

• Endosymbiotic theory
• Kingdom (biology)
• Eukaryote
• Prokaryote
• Evolutionary biology