Discovery Science: Earth – Evolution – Systematics

Earth Science: Biology – Evolution – Classification Of Living Things

Since ancient times, people have sought to systematically organize living organisms. Former classifications of the past mainly took outer features into consideration which was not necessarily very meaningful.

Therefore, they often do not reflect the actual genetic relationships between organisms. Today, scientists can use modern techniques to determine genetic relationships and produce pedigrees.

Earth Science: Biology – Evolution – Systematics

The aim of systematics is to describe the diversity of organisms, find distinctive characteristics, and classify them into groups of manageable size. There are two distinct methods of classification: artificial and natural classification.

In an artificial system, various organisms are assigned to a group according to similar characteristics. Here, the focus is on easily recognizable characteristics. One of the most famous artificial systems is the Systema naturalist which was developed by the Swedish physician and naturalist Carl Linnaeus. In this classification system, he grouped all plant and animal species he knew according to morphological features.

Notably, Linnaeus introduced the binomial nomenclature, which is still used up to this day. With this nomenclature each organism is given two names: a genus and a species name. This has the advantage of creating internationally standardized names which can be understood anywhere around the globe as opposed to the regional common names given to organisms. The selected name normally derives from a Latin or Greek description of characteristics.

Species with common features form a genus, similar genera form a family. Today, the main purpose of such a system is the quick and reliable identification of an individual organism.

Natural classification

Modern phylogenetic systems are based on evolutionary theory, which supports the idea that all organisms have evolved over time from ancestors with a less complex phylogeny. Organisms are classified according to either common or distinctive characteristics. It is assumed that groups are more closely related to each other the more features they have in common.

Phylogenetic relationships can only be derived from homologies. These are similarities that are based on common evolutionary roots. In contrast, convergences are similarities that have evolved through adaptation to similar functions and similar environmental conditions.

Such convergences are disregarded in natural classification systems. Today, actual phylogenetic relationships are sometimes determined by analyzing changes in sequence of certain nucleic acids that are determined to have a highly conserved structure.


The Systema naturae, first published in 1735, is considered a milestone of biological systematics. It was written by the Swedish physician and naturalist Carl Linnaeus, also known as Carl von Linne. Initially, he concentrated on the systematics of plants and used their reproductive organs as a basis of his classifications.

Later, he broadened his studies and included animals and even minerals. His binomial nomenclature first described in this work remains unchanged and in use even today. After being ennobled by the Swedish king for his outstanding work in 1762 he changed his original name to Carl von Linne’.