UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Reproductive isolation is a heuristic, not a measure: a commentary on Westram et al., 2022

Mallet, James; Mullen, Sean P; (2022) Reproductive isolation is a heuristic, not a measure: a commentary on Westram et al., 2022. Journal of Evolutionary Biology , 35 (9) pp. 1175-1182. 10.1111/jeb.14052. Green open access

[thumbnail of Mallet_Mullen_2022_On_RI_.pdf]
Preview
Text
Mallet_Mullen_2022_On_RI_.pdf - Other

Download (401kB) | Preview

Abstract

Reproductive isolation is the heuristic basis of the biological species concept, but what is it? Westram et al. (this issue) propose that it is a measurable quantity, “barrier strength,” that prevents gene flow among populations. However, their attempt to make the concept of reproductive isolation more scientific is unlikely to satisfy the diverse opinions of all evolutionary biologists. There are many different opinions about the nature of species, even under the biological species concept. Complete reproductive isolation, where gene flow is effectively zero, is regarded by some biologists as an important end point of speciation. Others, including Westram et al., argue for a more nuanced approach, and they also suggest that reproductive isolation may differ in different parts of the genome due to variation in genetic linkage to divergently selected loci. In contrast to both these approaches, we favour as a key criterion of speciation the stable coexistence of divergent populations in sympatry. Obviously, such populations must be reproductively isolated in some sense, but neither the fraction of the genome that is exchanged, nor measures of overall barrier strength acting on neutral variation will yield very precise predictions as to species status. Although an overall measure of reproductive isolation is virtually unattainable for these reasons, its early generation components, such as assortative mating, divergent selection, or hybrid inviability and sterility are readily measurable and remain informative. For example, we can make the prediction that to remain divergent in sympatry, almost all sexual species will require strong assortative mating, as well as some sort of ecological or intrinsic selection against hybrids and introgressed variants.

Type: Article
Title: Reproductive isolation is a heuristic, not a measure: a commentary on Westram et al., 2022
Location: Switzerland
Open access status: An open access version is available from UCL Discovery
DOI: 10.1111/jeb.14052
Publisher version: https://doi.org/10.1111/jeb.14052
Language: English
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: Science & Technology, Life Sciences & Biomedicine, Ecology, Evolutionary Biology, Genetics & Heredity, Environmental Sciences & Ecology, genotypic cluster, sympatry, species concept, speciation, gene flow, GENE FLOW, HYBRID ZONES, SPECIATION, SELECTION, VIEW, COMPONENTS, PATTERNS
UCL classification: UCL
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences > Genetics, Evolution and Environment
URI: https://discovery.ucl.ac.uk/id/eprint/10165518
Downloads since deposit
16Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item