Incipient radiation within the dominant Hawaiian tree Metrosideros polymorpha

Stacy, Elizabeth A.; Johansen, Jennifer; Sakishima, Tomoko; Price, Daniel O.; Pillon, Yohan

doi:10.1038/hdy.2014.47

Cited by 53 publications

(80 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Subsequent studies of nuclear microsatellite variation with limited sampling across the archipelago (Harbaugh, Wagner, Percy, James, & Fleischer, ) and of ISSR variation among bog and adjacent forest populations (Wright & Ranker, ) inferred extensive gene flow across islands, consistent with the high dispersability of the group's tiny seeds by wind and its pollen by birds and insects attracted to its showy, shaving‐brush inflorescences (Dawson & Stemmermann, ). Observations of isolation by distance at the scales of Hawaii Island (Stacy, Johansen, Sakishima, Price, & Pillon, ) and the entire archipelago (Percy et al, ; Wright & Ranker, ), however, suggest that distance‐dependent gene flow contributes to divergence of populations across some spatial scales.…”

Section: Introductionmentioning

confidence: 99%

“…A majority of taxa are single‐island endemics, with just a few spanning multiple islands (Table ). The many taxa of Metrosideros occur non‐randomly across a striking range of habitats from wet forests and deserts, to bogs, subalpine zones and riparian zones, and the group is emerging as a model for studies of ecological speciation in trees (Stacy et al, ). Two unusually widespread taxa, M .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Phylogeography of the highly dispersible landscape‐dominant woody species complex,Metrosideros, in Hawaii

Stacy

Sakishima

2019

Journal of Biogeography

View full text Add to dashboard Cite

Aim Little is known about how diversification occurs within long‐lived, highly dispersible and continuously distributed groups. We examined the distribution of genetic variation within the woody genus Metrosideros across the Hawaiian Islands for insights into how diversification occurs within this animal‐pollinated, wind‐dispersed group. Among Hawaiian plants, Metrosideros is unique in its formation of continuous stands within islands that span a remarkable range of environments and comprise numerous predominantly single‐island taxa. Location Hawaiian Islands. Taxon Metrosideros. Methods We performed population genetic analyses of variation at nine nuclear microsatellite loci from 1,486 adults of 23 Metrosideros morphotypes sampled from five main Hawaiian Islands plus additional Pacific Island populations. Results American Samoa and Tahiti populations clustered most closely with the older islands. Results also revealed isolation by distance across the archipelago, clustering of populations predominantly by island, and evidence of multiple colonizations or back‐colonizations of three islands. The number of genetic clusters peaked on islands of intermediate age, coincident with peak morphotype richness. All islands comprised a broad range of genetic distances among taxa with the greatest overall genetic distance observed on Oahu. The two taxa that are distributed broadly across the archipelago were weakly but significantly differentiated only on volcanically active Hawaii Island, where they partition early‐ and late‐successional environments. One of these taxa was positioned centrally both within individual‐island splitstree networks and across the archipelago‐wide network. Main conclusions Distance‐dependent gene flow contributes to isolation of Metrosideros across islands, especially on terminal islands. Morphological diversity likely accumulates rapidly within this group, likely associated with differential adaptation across heterogeneous environments, but isolation of gene pools through speciation within continuous Metrosideros stands likely requires persistent disruptive selection where environments are stable for long periods. The generalist, wet‐forest M. polymorpha var. glaberrima may play a central role in the generation of the group's many, largely island‐endemic, taxa.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Phylogeography of the highly dispersible landscape‐dominant woody species complex,Metrosideros, in Hawaii

Stacy

Sakishima

2019

Journal of Biogeography

View full text Add to dashboard Cite

show abstract

“…polymorpha and riparian var. newellii; Stacy et al, 2014). Ongoing introgression with forms of such contrasting leaf morphologies may also contribute to the weak genetic correlations within var.…”

Section: Genetic Architecture Of Leaf Traitsmentioning

confidence: 99%

“…Despite these functional differences, var. incana and glaberrima are the most weakly genetically differentiated pair of 'ohi'a varieties on Hawaiʻi Island (mean population pairwise F ST = 0.05 (Po0.01) versus F ST = 0.056-0.151 for other pairwise combinations of varieties; DeBoer and Stacy, 2013;Stacy et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Genetic analysis of an ephemeral intraspecific hybrid zone in the hypervariable tree, Metrosideros polymorpha, on Hawai‘i Island

et al. 2016

Self Cite

View full text Add to dashboard Cite

Intraspecific hybrid zones involving long-lived woody species are rare and can provide insights into the genetic basis of earlydiverging traits in speciation. Within the landscape-dominant Hawaiian tree, Metrosideros polymorpha, are morphologically distinct successional varieties, incana and glaberrima, that dominate new and old lava flows, respectively, below 1200 me on volcanically active Hawaiʻi Island, with var. glaberrima also extending to higher elevations and bogs. Here, we use morphological measurements on 86 adult trees to document the presence of an incana-glaberrima hybrid zone on the 1855 Mauna Loa lava flow on east Hawaiʻi Island and parent-offspring analysis of 1311 greenhouse seedlings from 71 crosses involving 72 adults to estimate heritabilities and genetic correlations among vegetative traits. Both the variation in adult leaf pubescence at the site and the consistency between adult and offspring phenotypes suggest the presence of two hybrid classes, F 1 s and var. incana backcrosses, as would be expected on a relatively young lava flow. Nine nuclear microsatellite loci failed to distinguish parental and hybrid genotypes. All four leaf traits examined showed an additive genetic basis with moderate to strong heritabilities, and genetic correlations were stronger for the more range-restricted var. incana. The differences between varieties in trait values, heritabilities and genetic correlations, coupled with high genetic variation within but low genetic variation between varieties, are consistent with a multi-million-year history of alternating periods of disruptive selection in contrasting environments and admixture in ephemeral hybrid zones. Finally, the contrasting genetic architectures suggest different evolutionary trajectories of leaf traits in these forms.

show abstract

“…Genetic research is revealing the mechanisms involved in the evolution of beak size in Darwin's finches [17] and the enormous plasticity of Metrosideros species: trees that dominate Hawaiian habitats from new lava to bogs to rainforests, but in which most of the plasticity is within species [18]. Growing databases (e.g.…”

Section: (B) Geneticsmentioning

confidence: 99%

Island biology: looking towards the future

2014

View full text Add to dashboard Cite

Oceanic islands are renowned for the profound scientific insights that their fascinating biotas have provided to biologists during the past two centuries. Research presented at Island Biology 2014-an international conference, held in Honolulu, Hawaii (7-11 July 2014), which attracted 253 presenters and 430 participants from at least 35 countries 1 -demonstrated that islands are reclaiming a leading role in ecology and evolution, especially for synthetic studies at the intersections of macroecology, evolution, community ecology and applied ecology. New dynamics in island biology are stimulated by four major developments. We are experiencing the emergence of a truly global and comprehensive island research community incorporating previously neglected islands and taxa. Macroecology and big-data analyses yield a wealth of global-scale synthetic studies and detailed multi-island comparisons, while other modern research approaches such as genomics, phylogenetic and functional ecology, and palaeoecology, are also dispersing to islands. And, increasingly tight collaborations between basic research and conservation management make islands places where new conservation solutions for the twenty-first century are being tested. Islands are home to a disproportionate share of the world's rare (and extinct) species, and there is an urgent need to develop increasingly collaborative and innovative research to address their conservation requirements.

show abstract

Incipient radiation within the dominant Hawaiian tree Metrosideros polymorpha

Cited by 53 publications

References 47 publications

Phylogeography of the highly dispersible landscape‐dominant woody species complex,Metrosideros, in Hawaii

Phylogeography of the highly dispersible landscape‐dominant woody species complex,Metrosideros, in Hawaii

Genetic analysis of an ephemeral intraspecific hybrid zone in the hypervariable tree, Metrosideros polymorpha, on Hawai‘i Island

Island biology: looking towards the future

Contact Info

Product

Resources

About