The Dutch scientist Anton van Leeuwenhoek builds a microscope powerful enough for him to observe and describe the red corpuscles in blood

With his powerful new microscope Leeuwenhoek observes spermatozoa in the semen of a dog

English naturalist John Ray begins publication of his Historia Plantarum, classifying some 18,600 plants in 'mutual fertility' species

Swedish naturalist Carolus Linnaeus publishes a 'system of nature', capable of classifying all living things

Captain Cook's distinguished passengers, Joseph Banks and Daniel Solander, collect valuable specimens of Pacific flora

French biologist Jean-Baptiste Lamarck argues in Zoological Philosophy that creatures can inherit acquired characteristics

A 12-year-old Dorset child, Mary Anning, discovers at Lyme Regis a 21 ft (6.4m) fossil of an icthyosaur

French scientist Georges Cuvier introduces scientific palaeontology with his Research on the Fossil Bones of Quadrupeds

HMS Beagle sails from Plymouth to survey the coasts of the southern hemisphere, with Charles Darwin as the expedition's naturalist

French zoologist Félix Dujardin identifies protoplasm, the viscous translucent substance common to all forms of life

HMS Beagle reaches Falmouth, in Cornwall, after a voyage of five years, and Charles Darwin brings with him a valuable collection of specimens

Swiss naturalist Louis Agassiz completes his pioneering Poissons Fossiles ('Fossil Fish'), classifying more than 1500 categories

An American clergyman, L.L. Langstroth, discovers the 'bee space', which becomes a standard feature of the modern beehive

Austrian monk Gregor Mendel begins his study of pea plants in the garden of the Abbey of St Thomas in Brno

English physician John Snow proves that cholera is spread by infected water (from a pump in London's Broad Street)

The first Neanderthal man to be discovered is unearthed by quarry workers in the Neander valley, near Düsseldorf

French chemist Louis Pasteur proves the existence of micro-organisms by showing that a liquid will only ferment if exposed to contamination from the air

Charles Darwin is alarmed to receive in his morning post a paper by Alfred Russell Wallace, outlining very much his own theory of evolution

Charles Darwin puts forward the theory of evolution in On the Origin of Species, the result of twenty years' research

Gregor Mendel reads a paper to the Natural History Society in Brno describing his discoveries in the field of genetics

English polymath Francis Galton publishes Inquiries in Human Faculty, developing the theme of eugenics and coining the term

In a paper to a congress in Madrid, on the 'psychology and psychopathology of animals', Ivan Pavlov announces his discovery of the conditioned reflex

German biologists Fritz Schaudinn and Erich Hoffmann discover the micro-organism Treponema pallidum which causes syphilis

English physiologists William Bayliss and Ernest Starling coin the word 'hormone' for glandular secretions into the bloodstream

English biologist William Bateson uses the word 'genetics' to describe the phenomenon of heredity and variation