Delineating species boundaries in tabular Acropora (project)

‘Species’ are central to understanding the origin and dynamics of biological diversity; explaining why lineages split into multiple distinct species is one of the main goals of evolutionary biology. However, the existence of species is often taken for granted, and precisely what is meant by species and whether they really exist as a pattern of nature has rarely been modelled or critically tested. This novel book presents a synthetic overview of the evolutionary biology of species, describing what species are, how they form, the consequences of species boundaries and diversity for evolution, and patterns of species accumulation over time. The central thesis is that species represent more than just a unit of taxonomy; they are a model of how diversity is structured as well as how groups of related organisms evolve. The author adopts an intentionally broad approach to consider what species constitute, both theoretically and empirically, and how we detect them, drawing on a wealth of examples from microbes to multicellular organisms.

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Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

Zootaxa ◽

10.11646/zootaxa.4379.1.3 ◽

2018 ◽

Vol 4379 (1) ◽

pp. 47 ◽

Cited By ~ 7

Author(s):

JACK M. CRAIG ◽

LUIZ R. MALABARBA ◽

WILLIAM G. R. CRAMPTON ◽

JAMES S. ALBERT

Keyword(s):

Lateral Line ◽

Electric Organ ◽

Valid Species ◽

Species Boundaries ◽

Multivariate Statistical ◽

Widespread Species ◽

Statistical Framework ◽

Fin Ray ◽

Taxonomic Confusion ◽

Electric Organ Discharges

Banded Knifefishes (Gymnotus, Gymnotidae) comprise the most species-rich, ecologically tolerant (eurytopic), and geographically widespread genus of Neotropical electric fishes (Gymnotiformes), with 40 valid species occupying most habitats and regions throughout the humid Neotropics. Despite substantial alpha-taxonomic work in recent years, parts of the genus remain characterized by taxonomic confusion. Here we describe and delimit species of the G. carapo and G. tigre clades from the southern Neotropics, using body proportions (caliper-based morphometrics), fin-ray, scale and laterosensory-pore counts (meristics), quantitative shape differences (geometric morphometrics), osteology, color patterns and electric organ discharges. We report these data from 174 Gymnotus specimens collected from 100 localities throughout the southern Neotropics, and delimit species boundaries in a multivariate statistical framework. We find six species of the G. carapo clade (G. carapo australis, G. cuia n. sp., G. chimarrao, G. omarorum, G. pantanal, and G. sylvius), and two species of the G. tigre clade (G. inaequilabiatus and G. paraguensis) in the southern Neotropics. The new species G. cuia is readily distinguished from the morphologically similar and broadly sympatric G. c. australis by a shorter head and deeper head and body, and from the morphologically similar and sympatric G. omarorum by fewer lateral-line ventral rami and fewer pored lateral-line scales anterior to the first ventral ramus. We also review the geographic distributions of all eight species of the G. carapo and G. tigre clades in the southern Neotropics, showing that G. cuia is the most widespread species in the region. These results affirm the importance of understanding the structure of variation within and between species, both geographic and ontogenetic, in delimiting species boundaries.

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How Mitonuclear Discordance and Geographic Variation Have Confounded Species Boundaries in a Widely Studied Snake

Molecular Phylogenetics and Evolution ◽

10.1016/j.ympev.2021.107194 ◽

2021 ◽

pp. 107194

Author(s):

Thomas L. Marshall ◽

E. Anne Chambers ◽

Mikhail V. Matz ◽

David M. Hillis

Keyword(s):

Geographic Variation ◽

Species Boundaries

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Phylogenomics of Palythoa (Hexacorallia: Zoantharia): probing species boundaries in a globally distributed genus

Coral Reefs ◽

10.1007/s00338-021-02128-4 ◽

2021 ◽

Author(s):

‘Ale‘alani Dudoit ◽

Maria E. A. Santos ◽

James D. Reimer ◽

Robert J. Toonen

Keyword(s):

Species Boundaries ◽

Globally Distributed

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Introgression between non-sister species of honeyeaters (Aves: Meliphagidae) several million years after speciation

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blz129 ◽

2019 ◽

Vol 128 (3) ◽

pp. 583-591

Author(s):

Leo Joseph ◽

Alex Drew ◽

Ian J Mason ◽

Jeffrey L Peters

Keyword(s):

Gene Flow ◽

Reproductive Isolation ◽

Sex Chromosomes ◽

Common Ancestor ◽

Sister Species ◽

Species Boundaries ◽

North Eastern ◽

The City

Abstract We reassessed whether two parapatric non-sister Australian honeyeater species (Aves: Meliphagidae), varied and mangrove honeyeaters (Gavicalis versicolor and G. fasciogularis, respectively), that diverged from a common ancestor c. 2.5 Mya intergrade in the Townsville area of north-eastern Queensland. Consistent with a previous specimen-based study, by using genomics methods we show one-way gene flow for autosomal but not Z-linked markers from varied into mangrove honeyeaters. Introgression barely extends south of the area of parapatry in and around the city of Townsville. While demonstrating the long-term porosity of species boundaries over several million years, our data also suggest a clear role of sex chromosomes in maintaining reproductive isolation.

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