Klement Arkadyevich Timiryazev was an outstanding Russian naturalist, specializing in plant physiology and photosynthesis. He became one of the first popularizers of Darwin's theory of evolution in Russia, as well as a well-known historian of science and a distinguished professor at Moscow University. Timiryazev was a corresponding member of the Petersburg Academy of Sciences and a foreign member of the Royal Society of London.

Klement Arkadyevich was born in 1843 in St. Petersburg. His father came from the ancient noble family of Timiryazevs, who served Moscow tsars even before the era of Peter I and had roots in the Golden Horde. His mother was from the family of the Bode barons, Franco-German Protestant aristocrats who lost their lands in Alsace after the French Revolution.

His father, Arkady Semyonovich, participated in the foreign campaigns of 1812 and 1814 and was known for his free-thinking views and honesty. Despite a successful career in the customs service, he did not accumulate wealth, so from the age of 15, Klement began to earn money on his own. He received his primary education at home.

Thanks to his mother, Adelaide Klimentyevna, Timiryazev was fluent in German and French, knew English, and was well-versed in Russian and English cultures. He often visited Great Britain, where he personally met Darwin and contributed to the development of plant physiology.

In 1860, Timiryazev entered St. Petersburg University, but in 1861 he was expelled for participating in student unrest and refusing to cooperate with the police. A year later, he was allowed to continue his studies as an auditor.

In 1867, he headed an agrochemical station in the Simbirsk province at the request of D. I. Mendeleev. In 1868, his first scientific work was published, and he was sent abroad to prepare for a professorship.

After returning to Russia, Timiryazev defended his master's thesis on the spectral analysis of chlorophyll and became a professor at the Petrovsk Agricultural and Forestry Academy. He taught botany until the academy closed in 1892. In 1875, he received a doctorate in botany for his work on the absorption of light by plants.

In 1877, he was invited to Moscow University to the Department of Plant Anatomy and Physiology, where he worked until 1911, when he left the university along with other professors due to the Kasso affair.

Timiryazev supported revolutionary ideas, seeing the Soviet power as a transition to liberal democracy. He believed that science and democracy should go hand in hand. As a deputy of the Moscow Soviet, he took this role seriously. At one of the meetings, he caught a cold and passed away in April 1920. He was buried at Vaganikovo Cemetery next to his family and his wife's relatives.