What is Systematics?

Introduction

Biological systematics is the scientific study of the kinds and diversity of organisms and any and all relationships among them. So, it is the study of biodiversity and its historical (evolutionary) and contemporary patterns and processes, which involves the comparative study of living and fossil species. This encompasses the science of describing, classifying and naming organisms (which is known as taxonomy), as well as the science of reconstructing the evolutionary history of the organisms (which is known as phylogenetic analysis). Systematists are thus the scientists whose expertise provides the data about the identification, description, distribution and relationships of life on Earth.

Taxonomy discovers and describes new species, while systematics uses evolutionary relationships to understand biogeography, coevolution, adaptation, and options for biological conservation. All aspects of biological and environmental science rely on taxonomy and systematics. Much of life on Earth is still unnamed and undescribed. We cannot prevent extinction and loss of biodiversity unless its basic units, the species and their relationships, are known.

Systematics can be seen as both the most basic and the most wide-ranging part of biology. It is the most basic because organisms cannot be discussed or treated in a scientific way until some taxonomy has been achieved, to recognize them and give them names. It is the most wide-ranging because it gathers together, utilizes and summarizes everything that is known about organisms, whether morphological, physiological, genetic or ecological.

Importance

Humans have a basic need to discover and understand the world around us. The knowledge derived from systematics helps meet this need. By revealing the diversity and patterns of life on Earth, as well as its origins and evolution, we can begin to understand the nature and history of our planet and our place within it.

This knowledge is also essential for our well being and long-term survival, because organisms, including our own species, interact together in a complex web of life. For example:-

nature is the ultimate source of our food, raw materials and many medicines;
we must be able to recognise, classify and understand the natural history of organisms in order to protect ourselves from diseases, pests and invasive species;
our knowledge of living species can be applied to monitor the quality of our environment;
our knowledge of living species can help us use the Earth's natural resources in a sustainable manner;
knowledge of fossil species reveals the progress and patterns of evolution, which enables us to interpret past environmental and climatic changes, so that we can interpret current trends more accurately and make predictions about the future.

Systematics is extremely important in regions like Australia, as Australia is recognised as one of the most biodiverse countries. Approximately 70% of the world's biodiversity resides in the top dozen countries. High diversity is usually measured by estimating each nation's total number of species, along with the number unique to that area (called "endemism"). In terms of numbers of species so far described, Australia is probably the number-one country for reptiles, while it varies from 11--14th rank for amphibians, mammals, birds and plants. In terms of number of endemic species, however, Australia is ranked 1st for reptiles and mammals, 2nd for birds, and 5th for plants and amphibians.

Activities

In practice, systematics is concerned with the following global activities:-

discovering and describing biological diversity;
elucidating the evolutionary relationships between organisms;
constructing hierarchical classifications of the organisms; and
devising and applying an unambiguous system of names for the organisms (nomenclature).

Systematists are involved in both basic and applied research, because systematics has a role in integrating the various parts of comparative biology as well as an importance in human affairs. For example:-

Systematics is central to all of biological science, as it provides the fundamental framework that allows scientists to compare their results amongst all living things. In particular, the names of organisms are the key to communications concerning biodiversity, as they provide access to the accumulated knowledge concerning all of life.
Systematics provides the knowledge and skills needed to discover and utilise new natural resources, as knowledge of the variety and inter-relationships of organisms has important applications in medicine, agriculture and industry. Notably, systematic knowledge underpins bioprospecting, the discovery of biological indicators, sustainable agriculture, and the sustainable utilisation of biological resources in the wild.
Systematics provides the knowledge and skills needed to catalogue and conserve the Earth's biodiversity, in particular the recognition of threatened species, the identification of areas of high diversity, and an understanding of ecosystem functions (such as the regulation of atmospheric gases, climatic effects, or the generation and maintenance of soil). It is thus of paramount importance for all nations wishing to fulfil their obligations under the international Convention on Biodiversity, at a time when biological diversity is being lost at an unprecedented rate.

The day-to-day activities of systematists deal with pursuits such as surveying fauna, flora and micro-organisms, identification of organisms, naming species that are new to science, data-basing collections of preserved or living specimens, and developing classifications. They also involve scientific studies, such as the analysis of:- biological variation, biogeography, evolutionary biology, and host-parasite relationships. The data used for these studies include those derived from:- morphology, anatomy, embryology, palynology, physiology, biochemistry, cytology, genetics, immunology, breeding experiments, ecology, geography, and palaeontology. In particular, the field of molecular systematics, involving the study of DNA and protein sequences, is radidly developing as an important new area.

Outcomes

There are a number of tangible and practical outcomes produced by systematists as part of their work, which are used by non-systematists as well:-

Names -- an internationally used standardized system for naming organisms allows everyone who uses or works with biodiversity to communicate their knowledge and to learn from the knowledge of others. These names are used by both scientists and non-scientists, such as horticulturalists, environmentalists, conservationists, politicians, lawyers, etc.
Identification -- systematics generates an understanding of the characteristics by which an organism can be identified. This is of fundamental importance to scientists. However, this information also allows the production of practical guides for those who need to identify species but have little or no specialist knowledge. Particularly popular these days are methods for interactive available on computer CD-ROMs.
Relationships -- systematics uncovers the natural relationships between groups of organisms, which are then used to organise the Earth's living diversity into hierarchical classifications based on evolutionary history. This understanding of relationships allows the directed search for new biological knowledge and resources, for example.
Collections -- the permanent reference collections that are the foundation of systematic biology are also widely used by other scientists and those working with natural resources. The preserved specimens are a verifiable record of variation in genetic make-up and body form, the past and recent geographical distribution of organisms, environmental change, and much other biological information.
Distributions -- both the collections themselves and the knowledge of systematic biologists are used to produce guides as to which species occur where in the world. This is important in natural-resource inventories as well as for legislative purposes. Systematists also generate knowledge of changes in the distribution of species with time, from rapid changes caused by human impacts to those occurring over geological timescales of millions of years.
Knowledge of natural history -- the knowledge and experience of systematists, and the data at their disposal, provide deeper understanding of their specialist groups, drawing together the results of other studies in genetics, physiology, development, evolution, behaviour and ecology. They also have unrivalled skills in locating and identifying organisms in natural environments.

Furthermore, in scientific research systematics is often at the heart of the procedures used. It has, for example:-

permitted the identification of the place of origin of emerging diseases and their vectors (e.g. Hanta virus, HIV, Nipah virus, West Nile virus);
enabled the reconstruction of the epidemiological history of disease transmission (e.g. HIV) as well as predicted locations of future outbreaks (e.g. Hanta virus);
allowed predictions of as-yet-unknown knowledge, such as parts of complex life cycles (e.g. neosporosis);
been used to reconstruct the history of functional changes in gene sequences that are linked to patterns of development (e.g. colour blindness) or disease (e.g. cancer);
guided analyses of vaccine efficiency (e.g. meningitis);
provided new approaches to forensic analysis;
guided the search for new pharmaceuticals or biotechnology products (e.g. anti-cancer drugs);
permitted the identification of invasive pest species as well as potential biological control agents.

Impediment

There is, however, a basic limitation to progress in the study of biodiversity, as there is a worldwide shortage of systematists. This shortage is expected to worsen, because the systematics workforce is aging, there is a decline in students being trained in systematics, and there is an on-going decrease in the number of paid positions that allow people to spend time doing basic taxonomy. These issues are discussed in more detail in:-

The Taxonomic Impediment and the Convention on Biodiversity
The Darwin Declaration.

There are particular problems in this regard in Australia, since it is recognized as one of the dozen most biodiverse countries in the world. Australia thus has a rich and very diverse flora and fauna that (at least for terrestrial organisms) is highly endemic (i.e. it occurs nowhere else). Documenting this biota is an enormous task -- it is estimated that Australia has 10-20% of the world's biota but has less than 1% of the world's systematists.

Broad-scale initiatives to support and promote the science of systematics have been developed in a number of countries. These initiatives aim to identify infrastructural needs for supporting systematic research, and to document the role and importance of systematics in human affairs. They include:-

The Global Taxonomy Initiative
Systematics Agenda 2000 - International
U.K. Systematics Forum
European Science Foundation Systematic Biology Network
Species 2000 programme
International Union of Biological Sciences' Diversitas programme
Tree of Life Workshop

Examples

Here are a few arbitrarily chosen examples of work involving systematists. They show examples of some of the output from systematics research, discoveries made by systematists, and some of the uses to which systematics is put, including contributions to the study of biodiversity:-