Carl Linnaeus, also known after his ennoblement as Carl von Linn , and who wrote under the Latinized name Carolus Linnaeus (May 23, 1707 – January 10, 1778), was a Swedish scientist who laid the foundations for the modern scheme of taxonomy. He is also considered one of the fathers of modern ecology (see History of ecology).
Carl Linnaeus was born at Stenbrohult , in the province of Smalandia in southern Sweden. Like his father and maternal grandfather, Linnaeus was groomed as a youth to be churchman, but he showed little enthusiasm for it. His interest in botany impressed a physician from his town and he was sent to study at Lund University, transferring to Uppsala University after one year.
During this time Linnaeus became convinced that in the stamens and pistils of flowers lay the basis for the classification of plants, and he wrote a short work on the subject that earned him the position of adjunct professor. In 1732 the Academy of Sciences at Uppsala financed his expedition to explore Lapland, then virtually unknown. The result of this was the Flora Laponica published in 1737.
Thereafter Linnaeus moved to the continent. While in the Netherlands he met Jan Frederik Gronovius and showed him a draft of his work on taxonomy, the Systema Naturae . In it, the unwieldy descriptions mostly used at the time, such as "physalis amno ramosissime ramis angulosis glabris foliis dentoserratis", were replaced by the concise and now familiar genus-species names in the form Physalis angulata . Higher taxa were constructed and arranged in a simple and orderly manner. Although the system now known as binomial nomenclature was developed by the Bauhin brothers almost 200 years earlier, Linnaeus may be said to have popularized it within the scientific community.
Linnaeus named taxa in ways that personally struck him as common-sensical; for example, human beings are Homo sapiens (see sapience), but he also described a second human species, Homo troglodytes ("cave-dwelling man", by which he meant the chimpanzee currently most often placed in a different genus as Pan troglodytes).
The group "mammalia" are named for their mammary glands because one of the defining characteristics of mammals is that they nurse their young. (Of all the features distinguishing the mammals from other animals, Linnaeus may have picked this one because of his views on the importance of natural motherhood. He campaigned against the practice of wet-nursing, declaring that even aristocratic women should be proud to nurse their own children).
In 1739 Linnaeus married Sara Morea, daughter of a physician. He ascended to the chair of medicine at Uppsala two years later, soon exchanging it for the chair of Botany. He continued to work on his classifications, extending them to the kingdom of animals and the kingdom of minerals. The last strikes us as somewhat odd, but the theory of evolution was still a long time away, and indeed, the Lutheran Linnaeus would have been horrified by it. Linnaeus was only attempting a convenient way of categorizing the elements of the natural world.
The Swedish king, Adolf Fredrik, ennobled Linnaeus in 1757, and after the privy council had confirmed the ennoblement Linnaeus took the surname von Linn, later often signing just Carl Linn. His father, born Nils Ingemarsson, had adopted the Latin surname Linnaeus as more appropriate for a clergyman on his matriculation at Lund University; the name deriving from the lime  tree after which the family farm, Linnagrd, took its name.
Although taxonomists, in almost any biological field, are familiar with the work of Carolus Linnaeus, his contribution to taxonomy goes far beyond contributing so-called scientific names to many of the world's plants and animals. Linnaeus developed, during the great 18th century expansion of natural history knowledge, what became known as the Linnaean taxonomy: the system of scientific classification now widely used in the biological sciences.
The Linnaean system classified living things within a hierarchy, starting with two kingdoms. Kingdoms were divided into classes and they, in turn, into orders, families, genera (singular: genus), and species (singular: species). Since then a few other ranks have been added, most notably phyla (singular: phylum) or divisions between kingdoms and classes. Groups of organisms at any rank are now called taxa (singular: taxon) or taxonomic groups.
His groupings were based upon shared physical characteristics. Although the groupings themselves have been significantly changed since Linnaeus' conception, as well as the principles behind them, he is credited with establishing the idea of a hierarchical structure of classification based upon observable characteristics.
Linnaeus was also a pioneer in defining the (controversial) concept of "race". He proposed that inside of Homo sapiens, there were four subcategories. These categories, Americanus, Asiaticus, Africanus, and Europeanus were based on place of origin at first, and later skin color. Each race had certain characteristics that members supposedly had. Native Americans were reddish, stubborn, and angered easily. Africans were black, relaxed and negligent. Asians were sallow, avaricious, and easily distracted. Europeans were white, gentle, and inventive. Linnaeus's races were clearly skewed in favour of Europeans. Over time, this classification led to a racial hierarchy, in which Europeans were at the top.