Theory of Evolution


Creation of Classification System


The “father of taxonomy” Carolus Linnaeus, a botanist and physician, created a system of classifying and naming organisms. Organisms are grouped by their similarities, but these reflect evolutionary patterns.

Buffon’s Contributions

Approx. 1749

Buffon, a French naturalist, suggested that species shared common ancestors. He challenged the belief that the Earth was only 6,000 years old.

Erasmus Darwin Contributions


Erasmus Darwin, a doctor who happened to be Charles Darwin’s grandfather, suggested that all organisms had evolved from a single common ancestor. He also believed that that one species could change into another species in an attempt to become more complex.

The Principle of Gradualism


James Hutton, a Scottish geologist, proposed that changes he observed in landforms was a result of slow and small changes over a long period of time. He believed that something such as a canyon was not suddenly cut out by a river. Rather eroded down over time to form a canyon. Charles Lyell would use this principle to form his theory of uniformitarism.

Principle of Population


Malthus, a cleric and scholar, published An Essay on the Principle of Population in 1798. He suggested that when humans have an abundance of food rather than just using what we need and having a good quality of life, we reproduce. This is exponential growth.

Theory of Catatrophism

Approx. 1800

Georges Cuvier, a French zoologist, proposed the theory of catastrophism. This states that natural diasters (volcanoes, earthquakes, etc) have shaped landforms. He also observed that rock layers in Earth had layers of changing fossils, suggesting that a species could go extinct. This was an unheard of idea at the time.

Inheritance of Acquired Characteristics


This idea was proposed by naturalist Lamarack. It suggested that changes in a organisms environment would cause a change in their behavior or body functions. And that these changes would be passed on to the organisms offspring. Lamarack also believed that all organisms evolved towards perfection.

The Principles of Geology


Charles Lyell, an English geologist, combined Hutton’s ideas of gradual change with his idea of change happening at a constant rate. This created his theory of uniformitarism. He published this in The Principles of Geology. He believed this proved that there was geological evidence that Earth was millions of years old. His theories and ideas would inspire Charles Darwin.

Theory of Evolution

Approx. 1850

Naturalist Alfred Wallace took a 8 year expedition to modern day Indonesia to observe wildlife. In 1855 he came to the conclusion that living things evolved. He published a joint paper with Charles Darwin arguing for the theory of evolution and natural selection.

On the Origin of Species


The naturalist Charles Darwin is usually given credit for Alfred Wallace’s discoveries of evolution and natural selection. Charles published this book building on the findings of himself and Wallace. it is considered the foundation of evolutionary biology, expanding the ideas of adaptations, variation, and much more.



For 8 years a monk names Gregor Mendel studied pea plants. He is known as the father or genetics as he suggested the laws of segregation, independent assortment, and dominance. His results from his pea experiment were published in 1865 and at the time were not well received. His work laid a foundation for genetics in the 1900’s.

Radiometric Dating


The New Zealand born physician discovered a method of determining how old dead organisms and rocks are by figuring out how much radioactive material is left in them. He was awarded a Noble Prize in 1908. Although he did not make discoveries about evolution, his technology has allowed researched to age fossils more accurately and make more conclusions about evolution.