Al-Jahiz was born in Basra in 776 CE to a poor family which is believed to be of Abyssinian descent. He was the author of Arabic literature, biology, zoology, Islamic philosophy and Mutazili theology. His father died when al-Jahiz was a few months old. Despite the familyâ€™s poverty, al-Jahizâ€™s mother was able to send her son through the local Quranic school. He received his nickname, Jahiz, (Jahiz: projected cornea) because he had a bulging eyes. Life in Basra provided al-Jahiz with many learning opportunities even after he left school. Basra was the home of Muâ€™talazite, a sect of Muslim school of thought, and al-Jahiz listened to scholars at the local mosque, informally learning from some of the greatest thinkers of the time. His mastery of the Arabic language and unusual intelligence won his admittance to Mutazili school of thinkers. Al-Jahiz achieved some fame and moved to Baghdad, where he continued to work as an advisor to the Khalifa. He suffered ill health in his later part of his life and moved to Basra where he died in December of 868 CE.
Al-Jahiz was the author of many books; Kitab al-Hayawan (The book of Animals) is one of his famous work. It is an encyclopedia of seven volumes of poetic descriptions of varieties of animals. Though, it is by no means a book of zoology, but it has description of a very keen study of animals and insects. He was the first person who studied the influence of the environment on animals and developed an early theory of evolution. Al-Jahiz considered the effects of the environment on the likelihood of an animal to survive, and thus he became the first person to describe the struggle for existence. His idea on the struggle for existence is not very different from Darwinâ€™s idea on this subject. In the Book of Animals he has summarized it like this; Animals engage in a struggle for existence; for resources, to avoid being eaten and to breed. Environmental factors influence organisms to develop new characteristics to ensure survival, thus transforming into new species. Animals that survive to breed can pass on their successful characteristics to offspring.
The above statement is so close to Darwinâ€™s theory of evolution, made more than a thousand years before Darwin. Indeed it seems that Darwin took al-Jahizâ€™s idea as a base and formulated his â€œtheory of evolutionâ€ in a more scientific way in context of nineteenth century scientific knowledge.
Al-Jahiz gave the idea of the food chain, saying all life depend on each other, even the hunting animal can become the part of food chain which he argued keeps a balance in the nature and maintains a proper ratio between the animals. He made an attempt to classify the animals in a linear series and arranged them in groups having marked similarity and then subgroups. He thus sowed the seed of scientific classification of animals.
He was also an early adherent of environmental determinism and explained how the environment can affect the physical characteristics of the inhabitants of a certain area of the world. He used his theories on natural selection and environmental factor to explain the origins of different human skin colors, particularly black skin, which he believed to be the result of the heat and humidity.
Al Jahiz is considered to be one of the most renowned and stylish writers of the Arabic literature. He is credited for establishing the rule of Arabic prose writing by collecting previously written anecdotes and giving his own instruction on the proper use of language and the importance of eloquence. He was really a naturalist, a satirist, a humorist, a theologian and a philosopher. He is believed to have written 350 books during his life span from all walks of knowledge and wisdom of his time. Most of his books have been lost only thirty have survived. His book: Kitab al Bayan wa al Tabyin which literally means (eloquence and demonstration), is one of his famous works, in which he approached various subjects, such as epiphanies, rhetorical speeches, sectarian leaders, princes, as well as giving a sardonic treatment to foolish and crazy people.
Al-Jahiz was a great man who proved that being dirt poor is no hindrance to seek higher education, even more than twelve century ago. His book Kitab al Hayawan had great influence on Muslim and European scientists like Lamark and Darwin.