Vertical differentiation in tropical forest butterflies: a novel mechanism generating insect diversity?

Many tropical fruit-feeding nymphalid butterflies are associated with either the forest canopy or the understorey; however, the exceptions offer insights into the origins of tropical diversity. As it occurs in both habitats of tropical forests in Ecuador and Peru, Archaeoprepona demophon is one such exception. We compared patterns of occurrence of A. demophon in the canopy and understorey and population genomic variation for evidence of ecological and genetic differentiation between habitats. We found that butterfly occurrences in the canopy were largely uncorrelated with occurrences in the understorey at both localities, indicating independent demographic patterns in the two habitats. We also documented modest, significant genome-level differentiation at both localities. Genetic differentiation between habitat types (separated by approx. 20 m in elevation) was comparable to levels of differentiation between sampling locations (approx. 1500 km). We conclude that canopy and understorey populations of A. demophon represent incipient independent evolutionary units. These findings support the hypothesis that divergence between canopy and understorey-associated populations might be a mechanism generating insect diversity in the tropics.

Download Full-text

Analysis of genetic differentiation and genomic variation to reveal potential regions of importance during maize improvement

BMC Plant Biology ◽

10.1186/s12870-015-0646-7 ◽

2015 ◽

Vol 15 (1) ◽

Cited By ~ 7

Author(s):

Xun Wu ◽

Yongxiang Li ◽

Xin Li ◽

Chunhui Li ◽

Yunsu Shi ◽

...

Keyword(s):

Genetic Differentiation ◽

Genomic Variation

Download Full-text

Past and future decline of tropical pelagic biodiversity

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1916923117 ◽

2020 ◽

Vol 117 (23) ◽

pp. 12891-12896 ◽

Cited By ~ 2

Author(s):

Moriaki Yasuhara ◽

Chih-Lin Wei ◽

Michal Kucera ◽

Mark J. Costello ◽

Derek P. Tittensor ◽

...

Keyword(s):

Environmental Control ◽

Research Question ◽

Ocean Warming ◽

Ice Age ◽

Deep Time ◽

Tropical Biodiversity ◽

Diversity Gradient ◽

Tropical Diversity ◽

Distribution Shifts ◽

The Tropics

A major research question concerning global pelagic biodiversity remains unanswered: when did the apparent tropical biodiversity depression (i.e., bimodality of latitudinal diversity gradient [LDG]) begin? The bimodal LDG may be a consequence of recent ocean warming or of deep-time evolutionary speciation and extinction processes. Using rich fossil datasets of planktonic foraminifers, we show here that a unimodal (or only weakly bimodal) diversity gradient, with a plateau in the tropics, occurred during the last ice age and has since then developed into a bimodal gradient through species distribution shifts driven by postglacial ocean warming. The bimodal LDG likely emerged before the Anthropocene and industrialization, and perhaps ∼15,000 y ago, indicating a strong environmental control of tropical diversity even before the start of anthropogenic warming. However, our model projections suggest that future anthropogenic warming further diminishes tropical pelagic diversity to a level not seen in millions of years.

Download Full-text

Fine-scale spatial and temporal genomic variation among Dungeness crab Cancer magister larval recruits in the California Current Ecosystem

Marine Ecology Progress Series ◽

10.3354/meps13453 ◽

2020 ◽

Vol 649 ◽

pp. 67-81

Author(s):

EMJ Lee ◽

KG O’Malley

Keyword(s):

Genetic Differentiation ◽

Genetic Relatedness ◽

California Current ◽

Population Connectivity ◽

Genomic Variation ◽

Fine Scale ◽

Dungeness Crab ◽

Spatial And Temporal Patterns ◽

Cancer Magister ◽

Late Season

Dynamic marine environments can shape complex spatial and temporal patterns in the population connectivity of marine species, and this is often exemplified in species with long larval phases. Here, we used a genotyping-by-sequencing (GBS) approach to examine fine-scale spatial and temporal genomic variation among Dungeness crab Cancer magister larval recruits sampled in the California Current Ecosystem. Specifically, we compared samples collected during expected- and late-season recruitment time periods within 2 consecutive years (2017 and 2018) at 2 sites in Oregon, USA (Yaquina Bay and Coos Bay). Evidence was found for high gene flow between the expected- and late-season recruits within each year and at both sites based on 1389 neutral loci. In contrast, strong genetic differentiation was observed between these 2 groups within each year and at both sites based on variation at 2 putatively adaptive loci. Contrary to prediction, the magnitude of genetic differentiation between these 2 seasonal groups was greater in 2017 when the Pacific Decadal Oscillation was stronger, upwelling was weaker, and the spring transition was later. Spatial genetic variation was not observed within 2017 or 2018. Comparing across years, expected- and late-season groups were differentiated at putatively adaptive loci. Interestingly, strong genetic differentiation was also observed between late-season groups across years. We found no evidence for cohesive larval dispersal among recruits based on genetic relatedness estimates. Overall, our findings provide evidence for high connectivity within Dungeness crab, but suggest that selective pressures and ocean conditions influence the genetic composition of larval recruits both intra- and inter-annually.

Download Full-text

Loss of dominant caterpillar genera in a protected tropical forest

10.1101/631028 ◽

2019 ◽

Author(s):

Danielle M. Salcido ◽

Matthew L. Forister ◽

Humberto Garcia Lopez ◽

Lee A. Dyer

Keyword(s):

Tropical Forest ◽

Ecosystem Function ◽

Biodiversity Loss ◽

Insect Diversity ◽

Negative Consequences ◽

Low Latitude ◽

Tropical Diversity ◽

Primary Consumers ◽

Abundance And Diversity ◽

Weather Anomalies

ABSTRACTReports of biodiversity loss have increasingly focused on the abundance and diversity of insects, but it is still unclear if substantive insect diversity losses are occurring in intact low-latitude forests. We collected 22 years of plant-caterpillar-parasitoid data in a protected tropical forest and found reductions in diversity and density of these insects that appear to be partly driven by a changing climate and weather anomalies. The decline in parasitism represents a reduction in an important ecosystem service: enemy control of primary consumers. The consequences of these changes are in many cases irreversible and are likely to be mirrored in nearby forests; overall declines in the region will have negative consequences for surrounding agriculture. The decline of important tropical taxa and associated ecosystem function illuminates the consequences of numerous threats to global insect diversity and provides additional impetus for research on tropical diversity.

Download Full-text

Genetic Stock Identification and Relative Contribution of Arctic Char (Salvelinus alpinus) from the Hornaday and Brock Rivers to Subsistence Fisheries in Darnley Bay, Northwest Territories + Supplementary Appendix Tables S1 to S4 (See Article Tools)

ARCTIC ◽

10.14430/arctic4578 ◽

2016 ◽

Vol 69 (3) ◽

pp. 231

Author(s):

Les N. Harris ◽

David A. Bogsuski ◽

Colin P. Gallagher ◽

Kimberly L. Howland

Keyword(s):

Life History ◽

Genetic Differentiation ◽

Salvelinus Alpinus ◽

Canadian Arctic ◽

Arctic Char ◽

Genetic Stock ◽

Subsistence Fisheries ◽

Bay Area ◽

Sampling Locations ◽

Mixed Stock

Where anadromous fishes occur in the Canadian Arctic, they provide the mainstay of local subsistence fisheries of varying intensities. Many of these fisheries harvest a mixture of stocks at discrete locations and it is often not known which stocks, specifically, are being harvested and to what extent. In the Darnley Bay area of the Northwest Territories, Arctic char, Salvelinus alpinus, in particular have long provided an important subsistence resource to residents of Paulatuk, and char from two systems (the Hornaday and Brock Rivers) are thought to contribute to the coastal fishery for this species. Genetic mixed-stock analysis (GMA) is routinely applied for resolving stock contributions to such fisheries, yet studies incorporating GMA to understand specifically which stocks are being harvested in the Canadian Arctic, and to what extent, are relatively scarce. In this study, we assayed microsatellite DNA variation among 987 Arctic char from two important coastal subsistence fisheries and several inland sampling locations in the Darnley Bay area to (1) assess the degree of genetic structuring between the Hornaday and Brock Rivers and (2) resolve the proportional contributions of these stocks to coastal mixed-stock fisheries in the region using GMA. Overall, genetic differentiation was relatively high and significant (θ = 0.117; 95% C.I. = 0.097–0.142) among baseline sampling locations. Overall patterns of genetic stock structure also support previous hypotheses that additional life history types (e.g., landlocked or freshwater-resident char, or both) exist in the Hornaday system, as indicated by elevated levels of genetic differentiation between some of our sampling locations. The GMA suggested that, while both river systems contribute to the coastal fishery, catches were dominated by Arctic char from the Hornaday River, which highlights the importance of this system. All told, our results may be relevant to the management of the subsistence fishery in Darnley Bay and for furthering the collective understanding of char biodiversity and life history variation in the Canadian Arctic.

Download Full-text

The Impact of the Colonization of the Invasive American Artemia franciscana (Crustacea: Anostraca) on Genetic Differentiation in the United Arab Emirates (Asia)

10.20944/preprints202003.0463.v1 ◽

2020 ◽

Author(s):

Alireza Asem ◽

Rolf Schuster ◽

Amin Eimanifar ◽

Hao Lu ◽

Muhan Li ◽

...

Keyword(s):

Genetic Differentiation ◽

San Francisco ◽

United Arab Emirates ◽

Salt Lake ◽

Artemia Franciscana ◽

Indigenous Populations ◽

Coi Gene ◽

Mediterranean Regions ◽

Demographic Patterns ◽

The Impact

Artemia franciscana, native to America, has recently colonized non-indigenous populations in Eurasia, Mediterranean regions and Australia. In present we sought to evaluate the potential effects of colonization of A. franciscana on genetic differentiation in the new environments in UAE. We used the COI marker to determine population genetic structure and identify the origins of exotic populations in UAE. Our findings have confirmed the colonization of both localities by A. franciscana. Genetic variation of invasive A. franciscana were exclusively lower than native population in Great Salt Lake and San Francisco Bay. Results have showed the studied population could not possibly have colonized directly from natural American localities, perhaps resulting from secondary introduction events from other non-indigenous populations. Genetic analysis have yielded different demographic patterns for invasive studied populations. Al Wathba Wetland Reserve (AWWR) population have represented demographic expansion. In contrast, Godolphin Lakes (GL) population was at demographic equilibrium. Neutrality tests have documented the excess of both recent and historical mutations in the COI gene pool of invasive AWWR Artemia throughout establishment in the new environment.

Download Full-text

Genome Skimming Reveals Widespread Hybridization in a Neotropical Flowering Plant Radiation

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.668281 ◽

2021 ◽

Vol 9 ◽

Author(s):

Oriane Loiseau ◽

Talita Mota Machado ◽

Margot Paris ◽

Darina Koubínová ◽

Kyle G. Dexter ◽

...

Keyword(s):

Plant Diversity ◽

Genomic Research ◽

Flowering Plant ◽

Tropical Plant ◽

Tropical Diversity ◽

Order Of Magnitude ◽

Adaptive Radiations ◽

Rapid Diversification ◽

Genome Skimming ◽

The Tropics

The tropics hold at least an order of magnitude greater plant diversity than the temperate zone, yet the reasons for this difference are still subject to debate. Much of tropical plant diversity is in highly speciose genera and understanding the drivers of such high species richness will help solve the tropical diversity enigma. Hybridization has recently been shown to underlie many adaptive radiations, but its role in the evolution of speciose tropical plant genera has received little attention. Here, we address this topic in the hyperdiverse Bromeliaceae genus Vriesea using genome skimming data covering the three genomic compartments. We find evidence for hybridization in ca. 11% of the species in our dataset, both within the genus and between Vriesea and other genera, which is commensurate with hybridization underlying the hyperdiversity of Vriesea, and potentially other genera in Tillandsioideae. While additional genomic research will be needed to further clarify the contribution of hybridization to the rapid diversification of Vriesea, our study provides an important first data point suggesting its importance to the evolution of tropical plant diversity.

Download Full-text