Change search
ReferencesLink to record
Permanent link

Direct link
The diversity and radiation of the largest monophyletic animal group on New Caledonia (Trichoptera: Ecnomidae: Agmina)
Stockholm University, Faculty of Science, Department of Zoology, Systematic Zoology.
Swedish Museum of Natural History, Entomology department.
2010 (English)In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 23, no 10, 2112-2122 p.Article in journal (Refereed) Published
Abstract [en]

In area, New Caledonia is the smallest of the world's 25 official biodiversity hotspots, but in many taxonomic groups, the island has the highest concentration of species on earth, particularly so in the freshwater insect order Trichoptera. This study aims at applying molecular data and morphology for estimating the real species diversity of the genus Agmina on New Caledonia and investigating potential effects of ultramafic rock substrate on diversification. A dated molecular phylogeny was applied to study diversity and diversification related to geological substrate using the dispersal-extinction-cladogenesis model, diva and Bayesian ancestral character reconstruction. More than 47 species (> 63%) were unknown to science. Initial radiation occurred on ultramafic substrate followed by several independent dispersal events to nonultramafic substrate. The rate of shift from ultramafic to nonultramafic substrate was significantly higher than the rate of shift in the opposite direction, indicating a possible cost associated with living on ultramafic substrate.

Place, publisher, year, edition, pages
2010. Vol. 23, no 10, 2112-2122 p.
Keyword [en]
Agmina, biogeography, diversification, Ecnomidae, evolution, freshwater, species diversity, south-west Pacific, Trichoptera, ultramafic substrate
National Category
URN: urn:nbn:se:su:diva-41152DOI: 10.1111/j.1420-9101.2010.02072.xISI: 000281827000008OAI: diva2:328534
Available from: 2010-07-05 Created: 2010-07-05 Last updated: 2011-12-01Bibliographically approved
In thesis
1. Diversification on an ancient Darwinian island: Evolutionary history of caddisflies (Trichoptera) and other organisms on New Caledonia
Open this publication in new window or tab >>Diversification on an ancient Darwinian island: Evolutionary history of caddisflies (Trichoptera) and other organisms on New Caledonia
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Islands are either of continental or oceanic origin, and the biota of such islands are a result of vicariance and dispersal, respectively. New Caledonia, in the South Pacific, is a part of former Gondwana, but the origin of its biota is heavily debated. Geological studies show that the island was submerged in the Eocene, and that oceanic crust was obducted onto New Caledonia leaving a thick layer of ultramafic rocks on top of the island. We tested the null hypothesis that New Caledonian biota are a result of old Gondwanan vicariance by fitting diversification models on phylogenies from the literature and calculating the gamma statistic. According to the null hypothesis diversification is gradual over time. If on the other hand the biota are a result of recent dispersal or have survived in refugia we would expect slowing of diversification over time. Based on our results we can reject the null hypothesis of old vicariance for the New Caledonian biota. The caddisfly (Trichoptera) fauna on New Caledonia is exceptionally rich with around 600 species, and more than 99.9% are endemic. Molecular phylogenetic hypotheses for three monophyletic caddisfly radiations, Xanthochorema, Caledopsyche et al. and Agmina, are presented. Age estimates agrees with the geological evidence. Three new species of Xanthochorema are described and more than 63% of the Agmina species are new to science. The ultramafic rock substrate, with high heavy metal concentration, has led to high levels of plant adaptation on New Caledonia. We show that caddisflies adapted early to this substrate and subsequently dispersed to non-ultramafic substrate several times, with significantly fewer dispersal events back to the toxic substrate, indicating that adaptation to ultramafic substrate is required and recolonization is difficult when this adaptation has been lost. Ultramafic substrate and other environmental factors have been important in driving the diversification of New Caledonian caddisflies.

Place, publisher, year, edition, pages
Stockholm: Department of Zoology, Stockholm University, 2010. 35 p.
New Caledonia, Trichoptera, island, biogeography, phylogenetics, DNA, dispersal, vicariance, adaptation, ultramafic, diversification, new species, environmental factors
Research subject
Systematic Zoology
urn:nbn:se:su:diva-41154 (URN)978-91-7447-114-4 (ISBN)
Public defence
2010-10-15, Lilla Hörsalen, Naturhistoriska Riksmuseet, Frescativägen 40, Stockholm, 13:00 (English)
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 5: AcceptedAvailable from: 2010-09-23 Created: 2010-07-05 Last updated: 2010-07-08Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Espeland, MarianneJohanson, Kjell Arne
By organisation
Systematic Zoology
In the same journal
Journal of Evolutionary Biology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 67 hits
ReferencesLink to record
Permanent link

Direct link