Classifying Nature

Linnaeus, Cuvier, Buffon

Linnaeus (Carl von Linnae, 1707-1778)

• Swedish naturalist who studied medicine in the Netherlands.

• Main concern was naming and classifying natural objects.

• Studied plants in Dutch gardens that had been collected from around the world.

Linnaeus • Journeyed to Lapland

to study the animals and plants, later published Flora Lapponica in 1737.

• Soon after his return, Linnaeus was offered a position as house physician and garden curator to George Clifford, a wealthy merchant.

Linnaeus

• 1735: Linnaeus published Systema Naturae, his first system for ordering natural history. He admitted that it was an “artificial” rather than a “natural” system, but felt that its utility justified using a less natural system.

• Linnaeus’ choice of terms reflect his cultural background. Referred to plant stamens as andria (“husband”) and pistils as gynia (“wife”). His writings refer to “marriages” between plants, including multiple spouses and concubines. Shocking to other Dutch naturalists, but his terms were adopted nevertheless.

Linnaeus

• 1736: Linnaeus formally publishes his system of binomial nomenclature. Proposes that all natural objects, including plants, animals, minerals, etc. receive a single name consisting of a genus and a specific epithet.

• 1753: Linnaeus publishes the Species Plantarum, a description and classification of known organisms. Included are human beings, given the species name Homo sapiens. Interestingly, Linnaeus also placed the known great apes in genus Homo.

Georges-Louis LeClerk, Compte de

Buffon 1707-1788

Thought an artificial taxonomy was a waste of time. Naturalists should search for a natural taxonomy, find the order in nature.

Asked by the King to catalog the Royal Garden collection, Buffon decided to catalog everything in nature.

Wrote 36 volume Histoire naturelle, générale et particulière.

Buffon• Buffon was a competitor of Linnaeus, advocating

for the development of a natural system of classification.

• In his Histoire, Buffon expressed tolerance for “folktale” biology found in Pliny and others, but contempt for later biologists who passed on these beliefs, calling them mindless compilers. However, several mythical creatures slipped into Buffon’s Histoire as well.

• His Histoire was entirely secular, yet he believed in an all-encompassing design in the nature and perfection in the natural world.

Buffon

• Buffon’s taxonomy was based on “natural families.” He noted, for example, that wolves, foxes, and dogs all have similar features, and constitute a natural family. Horses, zebras, and donkeys would belong to a different natural family.

• Later Buffon would propose an early theory of evolution, describing how organisms could change by their environment into similar species within the same natural family.

Georges Cuvier 1769-1832

Studied Buffon, and agreed that there should be a natural taxonomy.However, Cuvier parted with other taxonomists at the time, as he believed the taxonomic system should not be hierarchical.

Comparative anatomist: looking for patterns in structure, especially among vertebrate animals.

Cuvier

• Cuvier used internal anatomy of animals to sort them into categories, based mainly on neural anatomy: Vertebrata, Mollusca, Articulata, and Radiata.

• Though seeking a non-religious view of science (as he was working in post-Revolutionary France), Cuvier nevertheless accepted divine intervention in the form of a creation – and successive catastrophes and creations to explain fossil strata in the Paris basin.

Cuvier

• Cuvier’s Catastrophism relied on catastrophes and creations from outside the laws of physics (rather than catastrophic asteroid crashes we sometimes use today to explain extinctions, which are within the laws of physics).

• Cuvier also believed that species are fixed and do not change. If species are perfectly adapted to their habitat, how could they survive change. In Cuvier’s views, variation in a population was degeneration.

The Two Kingdom System• Linnaeus’ two-kingdom system for living

organisms was practical for naturalists working in the field, and eventually took precedence.

• In this system, all living organisms are classified as Animals or Plants (the Mineral kingdom encompassed the non-living part of the world). As time went on and microorganisms were studied more, problems arose with the two-kingdom system. Some organisms just didn’t fit neatly.