Functional traits are characteristics of individuals, populations and species that determine their fitness, via their impacts on growth, survival and reproduction. Examples are leaf size, leaf thickness, fruit size, wood density…. Traits are great proxies for the ecology of species, and used extensively in macroecological and macroevolutionary research. PalmTraits 1.0 provides species-level trait data for all ca. 2500 palm (Arecaceae) species worldwide. The database is available from Dryad. The article in which we present the data was published in Scientific Data.
What else did we (I and my collaborators) do with these data? For example, using average fruit size of palm species, we asked questions such as: Do large fruits co-occur with large-bodied animals that disperse these fruits? And: Does fruit size influence speciation rates via the interaction between fruits and fruit-eating and seed-dispersing animals? What happened to palms with large, ‘megafaunal’ fruits since the Quaternary extinctions of large-bodied animals?
Answers to these questions can be found in these publications:
Onstein, R.E. , Baker,W.J., Couvreur, T.L.P. , Faurby, S., Herrera-Alsina, L., Svenning, J.-C. & Kissling, W.D. (2018). “To adapt or go extinct? The fate of megafaunal palm fruits under past global change”. Proceedings of the Royal Society B 285: 20180882. [ABSTRACT] [PRESS RELEASE]
Onstein, R.E. , Baker,W.J., Couvreur, T.L.P. , Faurby, S. , Svenning, J.-C. & Kissling, W.D. (2017). “Frugivory-related traits promote speciation of tropical palms”. Nature Ecology & Evolution 1:1903–1911. [ABSTRACT] [DATA & CODE] [PRESS RELEASE] [BLOG]
However, the data can be used to answer many more questions, related to the ecology and evolution of palms. Species differ not only in their fruit sizes, but also in, for example, fruit colours, leaf structures and sizes, the presence or absence of spines, growth forms, plant height. In combination with distribution data and a phylogeny, we can now answer questions such as: when did these traits evolve? Where do species with these traits occur? Where do we find the most colourful fruits, and why? Where do species occur that have spines? Etcetera…
250 years ago (almost) Alexander von Humboldt was born, and became the “father of biogeography”. Journal of Biogeography decided to celebrate his birthday by publishing a ‘special issue‘ on Humboldt-related research, ranging from integrating geo- and biodiversity, to studying elevational and latitudinal diversity gradients and the impact of tectonism on biodiversity.
I contributed to three studies that were published in this special issue:
The first one I described in more detail in the last post – on how fruit traits in tropical plant families may explain historical long-distance dispersal events. Read more in the press release (in English or Dutch) or publication: , , , , , . Which frugivory‐related traits facilitated historical long‐distance dispersal in the custard apple family (Annonaceae)? J Biogeogr.2019; 46: 1874– 1888. https://doi.org/10.1111/jbi.13552.
The second one was led by Suzette Flantua and introduces one of the ideas that emerged during her PhD at the University of Amsterdam, where we met and discussed this idea extensively over coffee: that some of the extraordinary diversity in paramós (and mountains more generally) may have resulted from a process she named ‘flickering connectivity’. It’s the balance between connectivity (of populations) and disconnection over time that may drive speciation. In this publication we quantified this connectivity through the Pleistocene in the northern Andes, by making use of a pollen-core and detailed temperature reconstructions. To illustrate these ideas, one of the authors made this amazing video. Read more in the press-release: (in English or Dutch) and publication: , , , , . The flickering connectivity system of the north Andean páramos. J Biogeogr. 2019; 46: 1808– 1825. https://doi.org/10.1111/jbi.13607.
The third publication was led by Oskar Hagen, who is currently doing his PhD at the ETH in Zurich, Switserland (supervisor: Loïc Pellissier). He tries to understand how geological and biological processes interact in the generation of biodiversity (especially in mountains) – fitting very well in the Humboldt spirit. This publication addresses the origin of the Northern hemisphere mountain and Arctic floras, which have lots of lineages in common. Where did these lineages originate, and when? Where and when did cold ‘niches’ first emerge? To address these questions, we reconstructed cold niches throughout the Cenozoic by combining paleoclimate and paleoelevations, and combined these with species distribution data for cold-adapted taxa. Read more about it in the publication: Hagen, O, Vaterlaus, L, Albouy, C, et al. Mountain building, climate cooling and the richness of cold‐adapted plants in the Northern Hemisphere. J Biogeogr. 2019; 46: 1792– 1807. https://doi.org/10.1111/jbi.13653.
In October 2015 Hervé Sauquet, Thomas Couvreur and I went on a field expedition in the rainforests of Borneo. Our aim was to collect plants belonging to the order Magnoliales, which includes the Annonaceae family. Annonaceae have beautiful flowers and tasty fruits (e.g. the sweetsop and soursop), worldwide there are ca. 2400 species, and they typically occur in tropical rainforests. Our expedition led, eventually, to a publication: “Which frugivory‐related traits facilitated historical long‐distance dispersal in the custard apple family (Annonaceae)?” published in Journal of Biogeography. and co-authored by Daniel Kissling, Lars Chatrou, Thomas Couvreur, Hélène Morlon and Hervé Sauquet. Read the press release from the University of Amsterdam here. A video of our Borneo expedition is available here.
How did Annonaceae colonise different continents or islands and their rainforests? How did they get there? To understand this, we need to look into how the plants are dispersed, which is via their fruits and seeds. On Borneo, our aim was therefore to collect the fruits and measure their ‘traits’ (e.g. fruit length, seed length, conspicuousness of fruit display). These traits are important because they attract animals to feed on the fruits and disperse the seeds. We expected that certain fruit-eating and seed-dispersing animals (i.e. frugivores) are more likely to perform intercontinental long-distance dispersal. For example, large-bodied animals (megafauna, such as elephants) and strong-flying birds (e.g. hornbills) have large home-ranges and/or can cross barriers (such as oceans), and therefore move across large distances. Because these animals prefer certain fruits (e.g. large fruits, or fruits with particular colours) we expect that these Annonaceae fruits may have been responsible for intercontinental long-distance dispersal, for example from South America to Africa, which happened repeatedly in the family throughout its history. Our results confirm these expectations.
Besides fun in the rainforest, this research was important to me because it was my first postdoc, I received a Swiss Mobility Fellowship to perform it, and it allowed me to live in Paris for a while and work with a couple of amazing researchers. I hope to continue working with these people on this tasty family in the future. For example, a lot more genetic and functional trait data need to be collected to be able to understand the complex eco-evolutionary dynamics that have led to the spectacular Annonaceae diversity.
From left to right, starting at the top: Rafflesia flower; Goniothalmus roseus fruits; Thomas, Renske & Hervé in the field; rainforest Borneo; Enicosantum sp. flower; the fieldwork team in action (twice).
In the beginning of February, I organised a kick-off meeting for Laura Mendez‘ PhD project on “Genomic signatures of palms on Madagascar” – 3 days of discussions at iDiv in Leipzig (Germany). The team includes palm, frugivory and Madagascar experts from Kew Botanical Gardens, Aarhus University, University of Amsterdam, Bochum Botanical Gardens and iDiv – all important collaborators on Laura’s PhD project. The discussions ranged from deciding which species she will sample on Madagascar next summer, to clarifying the specific hypotheses and learning about historical demographic modelling techniques using Rad-seq data. A couple of very valuable and ‘fruitful’ days.
You probably wonder: what the hell is a Taproot? It also took me a while after arriving at the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig. But, it’s basically another word for a ‘research theme’, although Taproots may have different aims. We introduce the aims, participants and projects part of the iM2M Taproot (integrating meso to macro scales) in this video.
Within the iM2M theme we aim to bridge micro, meso and macro spatial/temporal scales in ecology and evolution. If you are part of iDiv and you’d like to join our meetings (every two weeks on Wednesday mornings in Leipzig), or would like to receive more general Taproot updates, please let me know (firstname.lastname@example.org).
With thanks to the iDiv media team!
I’m happy to announce that my proposal to make an outreach video about our work on Madagascar has been funded by the European Society for Evolutionary Biology (ESEB Outreach fund) and iDiv’s Female Scientists Career Fund.
Details will follow, but in short:
We aim to improve the understanding of evolutionary concepts (e.g. genetic connectivity, bottlenecks, speciation and extinction) at secondary schools. These concepts will be illustrated using video shootage from our fieldtrip to Madagascar (starring the new Evolution & Adaptation lab members Laura Mendez and Adriana Alzate!), as well as by use of animations. We study the evolutionary fate of Malagasy megafaunal-fruited plants (fruits > 3 cm) since the extinction of their primary seed dispersers: giant lemurs and elephant birds. Are these plants genetically adapting to new, smaller-bodied frugivores, or have they gone through genetic bottlenecks and are possibly facing extinction? The video will address these questions guided by the scientific and conservation activities performed by (female) researchers on Madagascar.