Race (biology): populations, differences, and taxonomic use
Biological race describes distinct populations within a species with modest morphological or genetic differences. The term contrasts with subspecies and has ecological, geographic, taxonomic, and conservation implications.
Overview
In biology, a race denotes a distinct population or group within a single species that shows relatively small but consistent differences from other populations. These differences can be visible (morphological) or detectable at the DNA level (genetic). The concept is used to describe structure below the level of species without necessarily assigning a formal taxonomic rank. For a basic sense of what constitutes a subdivided group, see population.
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Characteristics and criteria
Races are typically recognized by a combination of traits rather than a single diagnostic feature. Common criteria include modest divergence in external appearance, allele frequency shifts, and partial reproductive isolation. Descriptive terms connected to these criteria include morphological variation and genetic differentiation. The underlying processes often include adaptation to particular environments or limited gene flow between groups inhabiting different local habitats.
Types: ecological and geographic races
Two common ways races arise are ecological divergence and geographic separation. Ecological races appear when populations adapt to different niches within the same area, producing distinct forms without complete isolation. Geographic races (also called allopatric races) develop when barriers limit migration and gene exchange, allowing populations to drift and adapt independently. These categories are practical distinctions rather than rigid rules.
Races versus subspecies and taxonomic rank
When differences between races become pronounced and consistent, taxonomists may elevate the group to the formal rank of subspecies. Subspecies is an established level in biological taxonomy below species, whereas the label "race" often implies informality or uncertainty about assigning a formal rank. As noted by Ernst Mayr, "a subspecies is a geographic race that is sufficiently different taxonomically to be worthy of a separate name." This reflects how the same population can be treated differently depending on evidence and taxonomic philosophy.
Methods, examples, and uses
Researchers identify races using field observations, measurements of morphology, and genetic markers. Examples appear across plants, insects, birds, and mammals: a plant species may form distinct races on different soil types, while a bird may show subtle plumage or song differences among island populations. Recognizing races can guide conservation by identifying locally adapted or genetically distinct units that merit protection.
Controversies and practical considerations
The term "race" in biology carries potential for misunderstanding, especially in human contexts, and is used with care. Scientists prefer precise terms (population, lineage, subspecies, ecotype) and rely on explicit data rather than labels alone. Whether to name a unit formally depends on the consistency of differences, the degree of isolation, and the intended use of the classification (research, management, or communication).
- Key distinctions: ecological vs geographic origin, informal race vs formal subspecies.
- Common methods: morphology, population genetics, ecological study.
- Practical value: taxonomy, conservation prioritization, understanding evolution.
For further reading on related technical terms and foundational concepts, follow the linked terms above or consult comprehensive texts and reviews in evolutionary biology and systematics.
Use of terms, definition
Currently, "breed" is used taxonomically only for domestic animals and cultivated plants (compare race (breeding)), is scientifically obsolete and is increasingly out of use. In the rest of biology, the term has been used less and less since the 1950s. Although some biologists believe that it is possible to find human populations with genetic differences roughly corresponding to different ecotypes in other biological species, these populations have nothing in common with the traditionally defined human races, and use of the term race in the taxonomic sense is never justified because of the extensive gene flow between them.
The naturally evolved diversity within a species is now referred to as "genetic variation".
A definition from animal breeding was formulated by Hans Hinrich Sambraus:
"A breed is a group of farm animals which are largely similar to each other because of their common breeding history and appearance, but also because of certain physiological (= relating to metabolism) and ethological (= relating to behaviour) characteristics and performance."
A possible more general definition of race is (in the context of genetics):
"A phenotypically and/or geographically delineated subspecific group composed of individuals inhabiting a geographically or ecologically defined region that possess characteristic phenotype or gene sequences that distinguish them from similar groups. The number of racial groups one wishes to distinguish within a species is usually arbitrarily chosen, but should be appropriate to the purpose of the study."
This definition goes back essentially to the geneticist Theodosius Dobzhansky (1900-1975).
Currently, however, the formula "a breed is a breed if enough people testify to it" is just as valid among domestic animal geneticists, which makes it clear that there is no uniform and generally usable definition of the term here either.
The increasing avoidance of the term is based primarily on its use for "races of people". This concept was and still is used as a justification for racism. According to research on the genetics of human populations, the concept of the human race is scientifically outdated. Anthropologists and human geneticists, especially in the USA, continue to use the - not entirely congruent - term "race" in some cases (compare Race (United States Census)). Its use in the context of biomedical research is also still common in North America and has tended to increase again since around 2000 in the context of genomic research in connection with personalised medicine, even if this tends to be viewed critically by experts.
On 12 July 2018, the French National Assembly, on the initiative of President Macron and his party La République en Marche, unanimously decided to delete "race" from Article 1 of the French Constitution: The term, originally listed in it after World War II since 1946 as an antithesis to German Nazi racial theories, was outdated. In the prohibition of discrimination in Article 3 of the Basic Law for the Federal Republic of Germany, "race" is still listed.
Anthropology (human races)
→ Main article: Race theory and population (anthropology)
In different social and political milieus and at different times, the term "race" experienced different uses. Such subdivisions of humanity were sometimes neutrally intended attempts at classification, but usually, consciously or unconsciously, they were associated with evaluations; they were misused as apparent scientific bases for racism, or at least ethnocentrism, and for the justification of slavery. For most biologists of the age of colonialism, the superiority of the "white" or "Caucasian" race was beyond question, with members of one's own nation usually taking the top position. Many scientists, such as the biologist Ernst Haeckel, considered the difference between races to be so significant that, applied to a species other than man, it would suffice to distinguish several species. In Germany and other countries, these categorizations ultimately led to the National Socialists' "Aryan master race." These National Socialist ideas - without being identical to them, the focus on the Aryan originated not in biology but in linguistics - were capable of tying in with ideas of leading German anthropologists and human geneticists about the existence of human races, especially in connection with eugenic efforts, and also - for example at the leading university of Jena - with an overall anti-Semitic atmosphere and the widespread idea of weighty differences between Jews and other Europeans.
According to American biochemist and entrepreneur Craig Venter, whose company Celera Corporation sequenced an entire human genome (DNA) for the first time and published the result in September 2007,
"[...] the [human] genetic code doesn't determine race, it's purely a social construct [...] There are more differences between people of black skin color [themselves] than there are between people of black and light skin color, and there are more differences between so-called Caucasians than there are between Caucasians and non-Caucasians."
Corresponding differences in the appearance of humans have their cause above all in migration, selection due to evolution, environmental influences as well as socio-culturally different developments.
Questions and answers
Q: What is a race in biology?
A: In biology, a race is a distinct population within the same species with relatively small morphological and genetic differences.
Q: How are races classified?
A: Races can be classified as ecological races if they arise from adaptation to different local habitats or geographic races when they are geographically isolated.
Q: What is the official biological taxonomy unit below 'species'?
A: The official biological taxonomy unit below 'species' is subspecies.
Q: Should a formal rank be given to all races?
A: No, not all races should be given a formal rank; some may not qualify for one or taxonomists may be unsure whether or not to give them one.
Q: How does Ernst Mayr define a subspecies?
A: According to Ernst Mayr, "a subspecies is a geographic race that is sufficiently different taxonomically to be worthy of a separate name".
Related articles
Author
AlegsaOnline.com Race (biology): populations, differences, and taxonomic use Leandro Alegsa
URL: https://en.alegsaonline.com/art/80678
Sources
- goodrumj.com : goodrumj.com/Mayr.html
- hort.purdue.edu : Citrus aurantiifolia Swingle