Looking for a technical assistant to join the group

Details on how to apply can be found here: 174_iDiv_Tech_Assistant_EA_REO_engl (deadline 12th of August 2020).

Technical assistant Evolution & Adaptation group at iDiv (Leipzig, Germany)

Limited until 30 September 2021. 100% of a full-time position. Salary: Entgeltgruppe 6 TV-L. Workplace: Leipzig.

The Evolution & Adaptation research group focuses on the interchange between (macro-) ecology and evolution, to understand the global distribution of genetic, taxonomic and functional diversity. We therefore generate genetic (genomic) data (e.g. from plants from Madagascar), and build databases of biodiversity data (such as functional traits) to investigate the link between genes and phenotype. Understanding these links is important for predicting how adaptable biodiversity is to current and future global change.

Tasks:

  • Combining (botanical) data sources (such as monographs and floras) to build databases for biodiversity data (using Access/PROTEUS or SQL)
  • Measuring functional plant traits from herbaria or fresh sample material
  • Collecting and cleaning plant species occurrence data from online data sources/herbaria
  • General laboratory organization and maintenance
  • Planning and conducting basic molecular techniques
  • Analysis of generated data and preparation of suitable presentations

Requirements:

  • Professional qualification as a Biological-Technical Assistant or an equivalent degree (e.g. BSc or MSc in Biology)
  • Hands-on experience with basic molecular techniques (e.g., DNA/RNA isolation, PCR, real-time PCR, gel electrophoresis) preferable
  • Experience in building databases preferable
  • Very good computer skills (MS Windows, MS Office, R, etc.)
  • Very good spoken and written English
  • Strong team player also able to work independently
  • Very well organized and reliable
  • Experience with working in interdisciplinary and international teams

For questions, contact me on onsteinre@gmail.com!

Looking for two PhD students to join iDiv!

Application details for both positions are now available – see below!

I am looking for two new PhD students to join the Evolution & Adaptation group at iDiv in Leipzig (Germany) from October 2020 onwards. The positions are fully funded (65% of a full time employment, Salary: Entgeltgruppe 13 TV-L) and for 3 + 1 years. There is a budget available for consumables to perform fieldwork, lab work, sequencing, visit conferences, herbaria, collaborators and take courses. The PhD students will become part of the yDiv graduate school. iDiv is a very international place to work in and learn about Biodiversity science more generally, with weekly seminars, and Leipzig is a lovely city with lots of green space and a cultural history to live in.

Below I briefly describe both projects. Feel free to get in touch (onsteinre@gmail.com) to find out more, if you are interested in applying to one of them:

1. Macroecology and macroevolution of plant – frugivore trait matching in the tropics

Application details available from here: 113_iDiv_P3_REO_engl and 112_general_announcement__4thFlexPoolcall_engl. Deadline for application: 10th July 2020.

Background: Mutualistic interactions between fleshy-fruited plants and frugivorous animals are prominent in tropical rainforests. These interactions are facilitated by the evolution of matching traits in both plants and frugivores, such as fruit size and frugivore gape width. Due to ongoing global change (e.g., defaunation) trait matching may have been distorted in certain places, such as highly disrupted regions, leading to co-extinction or rapid evolutionary change in plants/animals that relied on these locally extinct interaction partners. However, which places harbour such mismatches in traits is unknown. Furthermore, it is unclear when these interaction-relevant traits evolved, and whether they have influenced the past diversification dynamics of plants and frugivores. In this PhD project, we aim to understand the impact of frugivory-related plant and disperser trait origin and extinction on the macroecology and macroevolution of fruit-frugivore trait matching, by addressing three main questions: (1) Do frugivory-related plant and animal dispersal syndromes (i.e., sets of correlated traits) differ among biogeographical realms, or mainland/island systems? (2) Is the spatial distribution of frugivory-related plant traits matched by the corresponding animal disperser traits (e.g., fruit size ~ gape width), or are there mismatches due to Late Quaternary extinctions of particular mammalian, avian or reptilian functional groups? (3) Has there been trait matching or mismatching during particular geological time periods, leading to increased (co-)speciation or extinction? To answer these questions, we will focus on three plant clades that are keystone resources for frugivores in the tropics: Arecaceae (palms), Annonaceae (custard apples) and Fabaceae – Mimosoideae (legumes). Furthermore, we will match the plant data to frugivore data, primarily focusing on frugivorous birds and mammals. We will integrate phylogenetic, distribution and functional trait data for these clades and apply macroecological and macroevolutionary methods to answer the research questions. This project will shed light on the biogeography of plant-frugivore interactions to be able to identify places and lineages prone to ongoing (co-)extinctions of their interaction partners. This project is supervised by me, Ingolf Kühn, Isabell Hensen and Irene Bender, but the student will work with several more collaborators for the specific datasets and their expertise on the plant and animal clades.

Tasks:

  • Developing specific research questions and hypotheses within the scope of the project;
  • Assembling/cleaning plant and animal frugivory-related traits, phylogenetic and distribution data from online databases, literature, monographs and herbarium visits (partly already done);
  • Applying macroecological and macroevolutionary methods to test the specific hypotheses;
  • Writing and publishing scientific papers in peer-reviewed journals;
  • Presenting results at national and international conferences;
  • Participation in iDiv’s PhD training program yDiv.

Requirements: Applicants should hold a Master’s or equivalent degree in a related field of research (e.g., biosystematics, (macro-)ecology, (macro-)evolution, environmental sciences). The successful candidate should be innovative, able to work on his or her own initiative, have expertise and experience in phylogenetics or working with phylogenetic data, interest and ability in handling spatial data and functional traits and strong statistical skills (in R). Candidates should be team-oriented and have strong organizational skills, in order to manage this collaborative research project within an international consortium. Excellent English communication skills (speaking and writing) are required. We seek candidates with an independent mind and the ambition to publish in internationally leading journals.

2. Adaptive evolution of plant-frugivore interactions on Madagascar

Application details available from here: 142_iDiv_PhD_Onstein_EA_engl. Deadline for application: 20th July 2020.

Background: Madagascar harbours exceptional biodiversity, but this tropical hotspot also faces increasing threat from human activities and climate change. Plants with large, ‘megafaunal’ fruits are common across the flora of Madagascar, especially within the palm (Arecaceae) family. However, Pleistocene-Holocene extinctions of large-bodied ‘megafaunal’ fruit-eating and seed-dispersing animals (such as giant lemurs) may have hindered the dispersal of taxa with megafaunal fruits. In this project we aim to investigate the molecular, micro- to macroevolutionary consequences of dispersal limitation in palms, specifically focusing on adaptive evolution of a megafaunal-fruited palm, Hyphaene coriacea, using a comparative framework of Madagascar (all megafauna extinct) and mainland Africa (where H. coriacea is still frequently dispersed by elephants). Specifically, we aim to (i) identify candidate genes for fruit and seed traits important for plant-frugivore interactions, (2) pick up genetic traces of selection or adaptation in relation to dispersal by smaller-bodied frugivores, and (3) evaluate the macroevolution of candidate genes or gene families across the palm family. This project integrates the fields of plant evolution, molecular evolution and plant-frugivore interaction ecology. It will be in collaboration with researchers from Hohenheim University (Prof. Philipp Schlüter) and University of Miami (Prof. Mauro Galetti), among others.

Tasks:

  • Collecting genetic samples from H. coriacea individuals and populations on Madagascar and mainland Africa, and measuring their functional traits (part of these samples have already been collected);
  • Collecting ecological information about the seed dispersal effectiveness (e.g., using camera traps) and demography of H. coriacea in the study areas;
  • Using novel genomic and transcriptomic techniques (e.g., RAD-seq, RNA-seq) to infer candidate genes for functional traits and evaluate traces of selection;
  • Writing and publishing of scientific papers in peer-reviewed journals;
  • Presentation of results at international conferences;
  • Participation in iDiv’s PhD training program yDiv.

Requirements: Applicants should hold a Master’s or equivalent degree in a related field of research (e.g. molecular biology, genetics, phylogenetics, population genomics, ecology and evolution). The successful candidate should be innovative, able to work on his or her own initiative, and willing to spend several months in the field (Madagascar/mainland Africa). Therefore, prior experience with tropical natural history, fieldwork and basic living conditions is advantageous. Furthermore, the successful candidate should have prior experience using molecular techniques, preferably with transcriptomics or bioinformatics, incl. the basics of scripting/programming for handling and statistically analysing large genetic/genomic datasets. Candidates should be team-oriented and have strong organizational skills, in order to manage this collaborative research project within an international consortium. Excellent English communication skills (speaking and writing) are required. We seek candidates with an independent mind and the ambition to publish in internationally leading journals.

 

 

Legume trait meeting in Leipzig

In the beginning of March 2020, just before COVID-19 took over Europe, we organised a Legume trait meeting at iDiv (Leipzig, Germany) which was also the PhD kick-off meeting for the PhD project of Francisco Velásquez Puentes. For his PhD, he will study the role of functional traits during biome transitions in Neotropical legumes, as well as diversification mechanisms in relation to drought adaptations and dispersal – from macro- as well microevolutionary (population genomic) points of view.

Our guests – all legume/trait/biome experts – travelled from the UK – University of Exeter (Toby Pennington), University of Edinburgh (Kyle Dexter, Flávia Pezzini)  – and Switzerland – University of Zurich (Colin Hughes, Erik Koenen, Jens Ringelberg, Elin Ruetimann). The 3 day meeting was insightful and initiated new ideas and initiatives which will hopefully substantialize in the coming years.

New article: Primate colour vision linked to palm fruit colours

Press release by iDiv (Kati Kietzmann)

Read the open access article here

Data for the article can be downloaded here

Colourful fruits may be the reason why primates can distinguish between shades of red, green and blue

Leipzig/Amsterdam. The evolution of colour vision might be closely linked to the availability of food. Researchers from the German Centre for Integrative Biodiversity Research (iDiv), Leipzig University (UL), and the University of Amsterdam (UvA) found that colour vision in African primate species, which is similar to that of humans, is related to the spatial distribution of palm fruit colours. The results of their study have been published in Proceedings of the Royal Society B. They shed new light on the evolution of primates.

In our retina, three kinds of receptors are responsible for the perception of basic colours: red, green and blue. The same holds true for many primate species – in contrast to all other mammals. For nocturnal species, the ability to distinguish different colours would not provide a significant advantage. It is therefore highly probable that so-called trichromatic vision developed in diurnal primates. In addition to greens and blues, they can also distinguish shades of red, making it easier to detect coloured fruit. This could provide a competitive advantage over other fruit-eating animals that cannot distinguish red from green. While this idea had been tested experimentally in a few species, it remained largely unexplored on a larger scale.

A team of researchers from iDiv, UL and UvA has now shown that trichromatic vision in primates is strongly linked to the availability of conspicuous, red palm fruits. Their research involved analysing data on the colour vision and distribution of more than 400 primate species as well as fruit colour data for over 1700 palm species. The result was clear: trichromatic vision in primates is most common in African countries with a high proportion of palm species with very colourful, conspicuous fruits.

This relationship is a win-win situation, benefiting both primates and palms: while primates rely on palm fruits as their primary food source, they are also important seed dispersers in tropical forests, particularly for large fruits. The research shows that the number of diurnal, fruit-eating primates in Africa increases with the proportion of conspicuous palm fruits, with a peak in subtropical regions. The results suggest that the effects of palm fruits on primates are strongest in the transition zones of arid to subtropical regions, where competition for food is also high. For the African primates, the ability to see several colours is thus an advantage when foraging. Palms, in turn, evolved colourful fruits that could be easily spotted by the primates, thus helping to disperse their seed.

The researchers did not only analyse data from the African continent, but also from Asia and the Americas. “Interestingly, in the Americas and Asia some primate species have trichromatic vision, whereas others do not. Here, we did not identify a relationship between colour vision and the proportion of conspicuous palm fruits,” said first author Dr Renske Onstein from iDiv and UL. Furthermore, most primates in the Americas prefer palm fruits with non-conspicuous colours. By contrast, many trichromatic primates in Asia have no interest whatsoever in a fruit’s colour – they enjoy feeding on large amounts of fruit in general.

“In Asia and the Americas, birds and bats could play a more important role as seed dispersers than primates,” explained Dr Daniel Kissling from UvA, senior author of the study. “In contrast, there are relatively few frugivorous birds on the African continent, so palm species may rely more on primates as seed dispersers than other fruit-eating animals.” The analyses show that palm species in Africa are dominated by those with conspicuous fruits, whereas the fruits of American species tend to be more inconspicuous.

Many primate species are now threatened with extinction due to rapid habitat loss and global changes. This may have cascading effects, especially when some plant species rely on primates as their primary seed dispersers. Thus, conservation efforts should also take plant-animal interactions and fruit-colour diversity into account as this is crucial for maintaining tropical biodiversity.

Original publication

Onstein RE, Vink DN, Veen J, Barratt CD, Flantua SGA, Wich SA, Kissling WD (2020). Palm fruit colours are linked to the broad-scale distribution and diversification of primate colour vision systems. Proc. R. Soc. B 20192731. DOI: 10.1098/rspb.2019.2731

http://rspb.royalsocietypublishing.org/lookup/doi/10.1098/rspb.2019.2731

Chimpanzee (Pan troglodytes) feeding on a wild date palm (Phoenix reclinata). (Picture: M. McLennan / Bulindi Chimpanzee & Community Project)

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The fate of megafaunal plants on Madagascar: the video

Link to video: https://vimeo.com/390453594

Plants with megafaunal fruits on Madagascar used to rely on megafaunal animals, such as giant lemurs and elephant birds, for their dispersal. Nowadays, these animals are extinct, and this may lead to dispersal limitation of plants with megafaunal fruits, and possibly their extinction. This video uses animations and footage from Madagascar to present our research to understand the consequences of megafaunal extinctions for palms with megafaunal fruits, and whether they need conservation prioritisation.

This video was made in collaboration with TRICKLABOR for the amazing animations. I also obtained an Outreach grant from the European Society of Evolutionary Biology (ESEB) and a grant from iDiv’s Female Scientist Career Fund to make this film project happen.

In the coming years we hope to find answers to the questions proposed in the video

Jungle_B6 copy

Trait flexibility leading to angiosperm success

As part of the “Tansley Medal” competition of the journal New Phytologist, I was asked to write a short (max 2500 words) Tansley Insight article. I applied for the competition a year ago, and was informed last April that I was short-listed. This pushed me to finally write this review, of which the topic dates from my PhD times.

I did my PhD at the University of Zurich as part of the ‘Cenozoic Angiosperm Radiation’ (CAR) project led by Prof. Peter Linder (who recently retired). The CAR team included several people, among them Colin Hughes, Yaowu Xing, Yanis Bouchenak-Khelladi and Erik Koenen. We would have Tuesday afternoon beers for several years to discuss ideas and projects. The main aim was to understand angiosperm radiations from phylogenies, fossils and functional traits, and we managed to tackle this question in several angiosperm clades, such as Fagales, Rhamnaceae, Proteaceae and Ericaceae. The emergent patterns across clades showed that radiations, or evolutionary diversification, is often the result of the intricate interaction between traits and environments. Screen Shot 2019-12-19 at 11.52.01

What remained an unanswered question, to me at least, was why angiosperms seem to have managed to radiate much more than other plant clades, such as gymnosperms, and also why not all angiosperm clades do equally well (in terms of their diversification rate). This question is not new, it was already proposed by Darwin (his second ‘abominable mystery’) and reviewed by Crepet and Niklas in 2009.

What I propose in my review, is that angiosperms (compared with gymnosperms) and species-rich angiosperm lineages (compared with species-poor lineages) have had (1) many trait innovations, (2) many ecological opportunities that emerged during Cenozoic global changes and (3) ‘trait flexibility’ to explore the functional space of novel traits, allowing for rapid adaptation to novel environments. These three ‘ingredients’ combined could lead to increased diversification rates. I quantified the support for this idea by performing a systematic review across the literature for trait-dependent diversification rates (key innovations) and trait transition rates (trait flexibility). Indeed, it seems that although no trait consistently leads to radiation across angiosperms, certain lineages may be predisposed to evolve the right traits in the right place at the right time, suggesting trait flexibility. This may have a genetic basis, and may explain why angiosperms have risen to dominance in most terrestrial ecosystems during the Cenozoic (i.e., the last 66 million years).

Hopefully it’s good enough to win the Tansley Medal.

Reference:

Onstein, RE (in press). “Darwin’s second ‘abominable mystery’: trait flexibility as the innovation leading to angiosperm diversity” New Phytologist. [ABSTRACT].

 

 

 

PalmTraits 1.0

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.

Screen Shot 2019-12-19 at 11.27.35

PalmTraits 1.0, Figure from the publication in the journal 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]

OnsteinR.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…

Humboldt in Journal of Biogeography

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.

Screen Shot 2019-07-26 at 13.55.48

Portrait of Alexander von Humboldt by Joseph Karl Stieler, painted in 1843, and shows Humboldt with a copy of his major work, “Kosmos”, and is owned by the Prussian Palaces and Gardens Foundation Berlin‐Brandenburg.

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: Onstein, REKissling, WDChatrou, LWCouvreur, TLPMorlon, HSauquet, HWhich frugivory‐related traits facilitated historical long‐distance dispersal in the custard apple family (Annonaceae)? J Biogeogr.2019461874– 1888https://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: Flantua, SGAO’Dea, AOnstein, REGiraldo, CHooghiemstra, HThe flickering connectivity system of the north Andean páramosJ Biogeogr2019461808– 1825https://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.

Fruits, animals and long-distance dispersal

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).