Postgraduate research Archives - Page 2 of 3

19/04/2016

School of Natural Sciences Postgraduate Symposium 2016: Part 3/3

Aoibheann Gaughran (@Aoibh_G)

Supervisor: Nicola Marples

Title: How population density influences social mammal ecology: A case study of the European badger.

The local density of a population of social mammals can affect many aspects of its ecology including social structure, mating systems, dispersal behavior, territorial behavior and the dynamics of disease. Scientists and policy-makers need a comprehensive understanding of the local population density as this may dictate the most effective management strategy. The European badger provides a particularly good species to investigate the effects of population density on other density parameters because its density varies by orders of magnitude across its wide geographic range. Further, it acts as a wildlife reservoir for bovine tuberculosis in the UK and Ireland, where it is subject to control operations. Currently, a haphazard classification of local population densities hampers a clear understanding of the badger’s ecology, leading to inappropriate management systems. We have conducted a meta-analysis to investigate the relationships between social group size, territory size, and group density and population density in badgers. We demonstrate that population density fundamentally alters badger ecology, affecting the interactions both within and between social groups. We also propose a classification system for densities of the European badger which highlight important ecological differences between populations across the density spectrum. Our findings provide a more cohesive picture of the species’ ecology across its range, facilitating appropriate targeting of disease management and conservation regimes.

Michelle McKeon-Bennett

Supervisor:Trevor Hodkinson

Title: Characterisation of endophytic microbes within Sphagnum magellanicum from Clara Bog, County Offaly, Ireland: Implications for enclosed environment hydroponic systems in Space.

This work investigates potential mutualistic relationships between endophytic microbes and species of native Sphagnum moss sampled from Clara Bog, County Offaly, Ireland. The application of the ion-exchange ability of Sphagnum moss to water remediation and recourse recovery within an enclosed hydroponic system has been investigated by the author at NASAs Space Life Science Laboratory, Kennedy Space Centre, Florida. While this research indicated that Sphagnum could be utilized in this manner, it resulted in yet more questions, specifically in relation to microbial interactions and growth mechanisms within the Sphagna:plant test bed.

It is postulated that endophytic microbes growing mutualistically within S. magellanicum may be responsible for (a) anti-algae and anti-microbe effects within the hydroponic system and (b) increased nutraceutical content within the associated salad crop. Microbial DNA isolated from 100ug samples of S. magellanicum, was extracted and used to identify microbial endophytes using standard barcoding primers. Genetic fingerprinting is being utilised to type the endophytes. Isolation and culturing protocols from Sphagnum plants have been developed and applied for the characterisation of microbial species during hydroponic systems using S. magellanicum as a growth medium. Further investigation of mutualism between identified endophytes and a cultivar of Lactuca sativa known as ‘Lollo Rosso’ is ongoing.

Alex O’Cinneide

Supervisor: Anna Davies & Martin Sokol

Title: The effectiveness of renewable energy policies in encouraging renewable energy generation.

Over the last twenty years the EU and its individual countries have been engaged in implementing policies to increase the use of renewable energy (RE) as a generation source. Motivations for this support of RE generation include, but are not limited to, concerns over climate change and pollution, national security risks associated with fossil fuels, and a wish to increase the competitive position of RE in markets which have been traditionally dominated by carbon based power. The issue of climate change and renewable power’s role in addressing this complex challenge has, in particular, been brought into sharper focus following agreement on emissions pledges from all the EU countries, and a new target of keeping global warming below 1.5C in December 2015 in Paris at COP 21; targets which will require a material response by policy makers throughout the EU. An understanding of what policies have been most effective in increasing RE is therefore critically important in designing new schemes, a comprehensive analysis of which has not been completed to date. I am therefore conducting a comparative analysis of the effectiveness of RE policies in encouraging RE generation (solar and wind, which given their advantages in cost and deployment have been the dominate focus of policy) across the EU from 1995 to 2015, with a primary focus on four countries of contrasting contexts, Ireland, UK, Italy and Portugal. While several studies have attempted to determine the effectiveness of various policies in various countries, these have been limited in scope and have not attempted to account for the variety of policy design features or individual country, market and key actor characteristics that influence policy strength. Adopting an energy transitions theoretical framework, this research would constitute the first study undertaken to determine how policy has effected the growth of renewables across Europe.

Anne Dubéarnès

Supervisor: John Parnell & Trevor Hodkinson

Title: Systematics of the genus Embelia Burm.f. (Primulaceae – Myrsinoideae)

Within the Primulaceae family, the Myrsinoideae form a highly variable tropical group, ranging from climbers and shrubs to trees, and characterised by the presence of dark dots on the leaves and fruits. This subfamily contains over 1300 species, divided into approximately 40 genera. Many of these genera are in need of taxonomic revision, as their limits are poorly defined and sometimes rely on ambiguous characters. Among these genera is Embelia, a genus of climbing shrubs distributed mostly in South and South-East Asia, tropical Africa and Madagascar. Embelia displays extensive morphological variation – especially regarding the position, shape, size and merosity of the inflorescences and flowers. It is distinguished from other Myrsinoideae only by the climbing habit, and the relationship with morphologically similar genera has not been critically evaluated yet. The last monograph of Embelia by Mez (1902), recognised eight subgenera and 92 species, but the total number of species is currently estimated at 150-200, and the subgenera used by Mez must be assessed and refined. My project aims to combine morphological and molecular data in order to test the monophyly of Embelia and to provide a taxonomic framework of the subgenera.

Eoin Mac Réamoinn

Supervisor:Cliona O’Farrelly & Paula Murphy

Title: Toll-Like Receptor Gene Expression During Early Murine Embryonic Development.

Toll-like receptors (TLRs) are renowned for their fundamental roles in immunological surveillance and response initiation. While TLR proteins in invertebrate species, such as Drosophila, carry out functions in the immune system and in “building” the body plan in the embryo, such non-immune functions have not been thoroughly investigated in mammals. Although TLR genes have duplicated independently in these lineages, and may therefore have diverged in aspects of their functionality, limited studies have recently reported the expression of TLRs in the developing mammalian embryo (Kaul et al., 2012). We report a systematic study of Tlr gene expression in early to mid-gestational murine embryos using whole-mount RNA in situ hybridization and 3D imaging (using Optical Project Tomography), the combination of which has allowed us to record the precise tissues and stages at which these genes become expressed. We have found that the expression of these receptors is particularly enriched within the central nervous system with many Tlrs displaying complementary expression patterns in developing neural tissues, as is the case with Tlrs -1, -5, -6, and -7 in the neural tube at embryonic day 10.5. These findings are in line with experimental data showing that Tlrs -2, -3, and -4 can influence neural progenitor cell proliferation and self-renewal (as reviewed in Barak et al., 2014). In addition to the expression data we have generated, whole-transciptome data is being mined to build a comprehensive picture of Tlr activity during embryogenesis and will aid in the building of specific hypotheses for functional testing.

19/04/2016

School of Natural Science Postgraduate Symposium 2016: Part 2/3

Aoife Delaney (@Ifa_Dee)

Supervisor: Jane Stout

Title: Do principals of cross congruence apply in a naturally disturbed habitat?

Cross congruence is a measure of the degree to which diversity (number or composition of species) of different taxa follow broadly similar patterns in response to environmental conditions. In situations where cross congruence is strong, measuring the diversity of a single taxon can provide information regarding overall diversity, and this has led to the development of indicator taxa. Indicator taxa may be used to indicate general patterns of biological diversity or environmental conditions, often with the inference that where the environmental conditions are favourable for one taxon, other target taxa will benefit. The use of indicator taxa has obvious economic appeal, but cross congruence has been shown to vary greatly in different studies. Habitat heterogeneity and environmental stress can reduce the correlation of diversity among different taxonomic groups.

Within the EU, states which have signed up to the Habitats Directive (Council Directive 92/43/EEC) monitor the condition of habitats of conservation concern (Annex I habitats) using standard methods and report their results to the European Commission. Indicator species are used as part of this habitat assessment. Dune slacks, an EU Annex I habitat, are temporary ponds in sand dunes which can persist for long periods, many having been formed as part of the initial dune-building phase. Despite being stable physical features, they experience both environmental stress (annual flooding and desiccation) and temporal habitat heterogeneity, and this raises questions: do principals of cross-congruence apply here, and are indicator species effective? This study compared patterns of diversity among three different taxonomic groups, to test whether cross congruence was observed. Communities of plants, snails and water beetles in twenty-four dune slacks in Ireland were compared using diversity indices and ordination techniques. Dune slacks were assessed on the basis of the indicator species used in reporting to the European Commission, and the biological assemblages of sites which passed and failed the assessment were compared. The results of this research will help to evaluate current monitoring techniques which are in use throughout the EU and guide monitoring approaches for dune slacks in Ireland.

Qiang Yang (Marvin) (@MarvinQiangYang )

Supervisor: Ian Donahue & Andrew Jackson

Title: Stronger perturbations increase the complexity of ecological stability

The stability of ecosystems determines the sustainability of the biological resource and services that nature offers us, and an understanding of mechanisms and drivers of ecological stability has vast implications for the sustainability and management of natural resources as well as the protection and restoration of ecosystems. Much effort has been contributed to understanding the factor that determines the stability of biological communities. A challenging aspect of stability is its many components, including asymptotic stability, resilience, resistance, robustness, persistence, variability and so on, but most of the previous research failed to analyse ecological stability from an comprehensive angle and we know remarkably little about the mechanisms underpinning relationships among components of stability. Therefore, focus on single stability elements may cause an underestimate of the “real stability” of ecosystems. Here in our research, by simulating the dynamics of 13 four-species food webs following perturbations varying in strength, we show that stronger perturbations decouple the relationship between stability components, i.e. that the efficacy of the single stability element in representing the general character of ecological stability becomes lower under strong perturbations. It is therefore necessary to investigate ecosystem stability from multiple angles, especially under strong disturbance frequently shown in real nature. The decoupling effect of perturbations on the multidimensionality of ecological stability is universal across most of the 14 food-web motifs in our research, implying a similar pattern in more complex large ecological networks.

Alewynne McGeever (@AlwynneMcGeever)

Supervisor: Fraser Mitchell

Title: Population dynamics of Pinus and Ulmus in Europe during the Holocene.

This work investigates and compares the population dynamics of Pinus and Ulmus in Europe, during the Holocene, at varying temporal and spatial scales, by using recently developed and novel modelling methods. The first component characterises the European-wide post glacial rise and mid-Holocene decline experienced by both genera. Pollen data was extracted from 330 sites on the European Pollen Database (EPD). The depth of rise and decline events for each genus in each site core was defined by applying a spline curve, to remove stochastic noise from the pollen data, and identifying the range of depths along which the pollen values increased or decreased.

The R package Bchron was used to calibrate radiocarbon dates and produce an age-depth model for each site, using stochastic linear interpolation and Monte Carlo methods. The age-depth model data was applied to the event depth range to produce a probability distribution of when the rise and decline events occurred.

The second component characterises Ulmus and Pinus when they were abundant on the European landscape. Depth and magnitude data of maximum pollen values for both genera were gathered from the EPD. The age-depth models were used to determine the age of the maximum pollen value depths.

These data were then plotted on maps and empirical Bayesian kriging was used to interpolate the spatial and temporal dynamics of these population events in the two tree genera. This work, therefore, presents novel techniques to quantifying tree population dynamics, and also provides insight into the specific dynamics of two major tree genera in Europe.

Dongwei Zhao

Supervisor: John Parnell & Trevor Hodkinson

Title: Phylogenetics of Camellia (Theaceae) in Indochinese Peninsula

Tea, camellias and oil camellias from the genus Camellia L. (Theaceae) are commercially highly important. About one third of all known Camellia species occur in the Indochinese Peninsula, of which half are endemic. Many new names of Camellia are still being described from this area, which may suggest that it was previously under-collected. Almost no work, however, has focused on the phylogenetics of Camellia in this area. This project aims to address these issues using morphological and molecular approaches. Morphological studies, consisting of a comparison and description of various macro-characters of specimens and palynological analyses, will be undertaken to clarify the boundaries of species in this notoriously variable genus. DNA markers derived from nuclear and chloroplast genomes will be selected to generate molecular sequence data, which will be used to reconstruct a robust phylogenetic tree. A new classification of this genus could then be proposed based on both morphological and molecular data. Species that have potential to supply new traits to the cultivars of tea, camellias and oil camellias could also be identified.

Conor Owens (@conorhpwns )

Supervisor: Fraser Mitchell & Jane Stout

Title: Biodiversity in willow evapotranspiration systems for wastewater treatment

Constructed wetlands are increasingly seen in Ireland and abroad as a solution to the on-site treatment of wastewater from domestic and other sources in rural areas. They are likely permanent features in our landscape that will proliferate into the future. Willow evapotranspiration systems are a subtype suitable for application in areas with low permeability subsoils. These systems are often promoted as having a beneficial role with respect to biodiversity but this has not been rigorously evaluated. This project aims to assess the plant and invertebrate biodiversity of these systems and the contribution they make to the biodiversity of the wider landscape. The factors driving biodiversity in these systems are being investigated and thus this project will provide management recommendations to maximise this biodiversity. This project involves cross discipline collaboration, drawing on expertise from both the TCD School of Natural Sciences and the TCD School of Engineering.

19/04/2016

School of Natural Sciences Postgraduate Symposium 2016: Part 1/3

School of Natural Sciences Postgraduate Symposium 2016: Part 1/3

#zoobotpgsymp, not an infection transmitted by botflies, but the hashtag of the annual Botany-Zoology postgraduate symposium, hosted by the School of Natural Sciences, which took place on the 14th of April.

This year’s symposium hosted 15 student speakers over 2 sessions of talks as well as two pleniaries delivered by our guest speakers: Dr Nina Alphey (University of Oxford, Imperial College London) and Dr Rob Thomas (University of Cardiff).

For those of you who are interested in exactly what we work on here at EcoEvo@TCD, here are the abstracts from the PhD student presentations. Check out the TCD website for more details!

Darren O’Connell (@oconned5)

Supervisors: Nicola Marples & David Kelly

Title: Ecological character displacement as a driver of diversification

Since Darwin, competition has been recognised as an important factor driving diversification. Competition is energetically expensive and unstable, so direct competition is rarely observed. One way in which species can avoid competition is ecological character displacement. This is where differences between similar species are accentuated when they co-occur but are lost or minimised when they do not overlap.

We suspect this process may have occurred in our study system of south-east Sulawesi, Indonesia. Two closely related and similarly sized species of kingfisher occur in this region, one resident and one migratory. On the Sulawesi mainland and larger (continental) islands they spatially segregate by habitat and resource partitioning. On the smaller islands of the Wakatobi Archipelago there is less habitat diversity and we do not see evidence of either habitat or resource partitioning. We do see a shift in morphology of one of the competing species, the resident Collared Kingfisher (Todiramphus chloris). The Wakatobi population is larger (wing and bill) than mainland populations. The change in habitat structure on the Wakatobi Archipelago bringing these species into closer contact may have promoted this divergence in morphology to alleviate potential competition.

Preliminary genetic work shows divergence between Collared Kingfisher populations of the Wakatobi and Sulawesi mainland, indicating the taxonomy of these populations requires further assessment.

Sukontip Sirimongkol

Supervisor: John Parnell

Title: Morphological characters of Henckelia Spreng (Gesneriaceae)

The genus Henckelia is one of the most complicated genera in the family Gesneriaceae. Recent molecular phylogenetic studies on Chirita and Henckelia are presented. These have separated Chirita from other genera such as Henckelia, Damrongia, Microchirita, Liebigia and Primulina. Some members Henckelia have been moved to other genera including Codonoboea, Didissandra, Didymocarpus, Lindernia and Loxocarpus resulting in a reduction in the number of Henckelia species to 57. Defining morphological characters for Henckelia allowing separation from these other genera are as yet unclear but will be derived from materials collected on fieldwork. In addition, for these morphological studies, specimens lent from Aarhus University Herbarium (AAU), University of Aberdeen (ABD), The Natural History Museum (BM), The Forest Herbarium (BKF), Bangkok Herbarium (BK), Royal Botanic Garden Edinburgh (E), Royal Botanic Gardens (K), Kunming Institute of Botany (KUN), The National Herbarium Nederland (L), Singapore Botanic Gardens (SING) will be used. The final thesis will therefore be in part molecular but with palynological, ecological, morphological and biogeographic data. This will allow for a revision of Henckelia in Thailand and Indo-China including Myanmar and Southern China.

Dermott McMorrough (@derm_mcm)

Supervisor: Andrew Jackson

Title: Now you see me: Examining the variation in time perception

Sight is one of our most valuable senses: constantly feeding us information about our environment, allowing us to evaluate potential mates, and perhaps most importantly: enabling us to find food. In the animal kingdom, a number of strategies are deployed as individuals and groups go about finding the food necessary for moving, growing, and ultimately passing on ones genes.

The way in which animals and humans acquire, process, and act upon visual information is a highly evolved, intricate process played out over minuscule time scales. In the time it takes for a predator to realise that its prey is about to change direction, or for an expert batsman to notice the spin on an approaching baseball, it is often too late to act. Our knowledge of temporal variation in this key trait lag in comparison with our understanding of spatial acuity.

Using a combination of simulation and psychometric techniques, I aim to tease apart the relationship between information acquisition over discreet temporal scales and the evolutionary consequences for both animal and human systems.

Anindita Lahiri

Supervisor: Trevor Hodkinson, Gerry Douglas, Brian Murphy & Colin Kelleher

Title: Characterizing candidate disease resistance loci in ash (Fraxinus) and an assessment of ash fungal endophyte strain variation in Ireland

Ash is very useful and abundant tree found throughout Europe, which is now threatened considerably because of a disease called ash dieback. It is caused by a fungal pathogen known as Hymenoscyphus fraxineus Baral. It can damage plants irrespective of their age group but young plants are more susceptible to the disease. Ash dieback starts from the midrib of the leaves and travels through the midrib to the stem part of the plant where the fungal mycelia blocks the xylem and phloem vessels and the plant dies because of lack of water and nutrients. This project is currently undertaking a comprehensive study of the leaf fungal endophytes of healthy plants to characterize their microbiome. We have cultured endophytes in a malt extract agar media and isolated them on the same media by sub-culturing. We are currently amplifying nuclear ribosomal bar coding DNA regions and sequencing them to identify the fungal isolates. We will then test the biocontrol potential of some of these against the disease pathogen.

Maureen Williams (@MoDubs11)

Supervisor: Ian Donohue & Celia Holland

Title: Does parasitism interact with warming to modify energy flow in ecosystems?

Gammerid amphipods are key components of aquatic ecosystems around the globe, acting as important detritivores and frequently dominating benthic assemblages in both rivers and lakes. Their ability to process detritus and return nutrients to the ecosystem may, however, be undermined by infection with behaviour-modifying acanthocephalan parasites. Moreover, as gammerids are ectothermic, the impact of parasitic infection could also vary with temperature. We explore whether parasitism and warming interact to modify energy flow in ecosystems by comparing individual energy budgets for Gammarus duebeni that were infected with the common acanthocephalan parasite Polymorphus minutus, with those of uninfected individuals of similar size across a broad range of temperatures.

09/02/2016

Listening to Evolutionary Oddities @TEDxUCD

Last December I was asked to participate in the TEDxUCD 2015 event. The event included 9 national and international speakers with a wide range of ideas worth spreading. Despite being asked to participate only two days prior to the event luckily I could draw on the wide research area encompassed in my new Post Doc position using the COMPADRE and COMADRE databases to study patterns in demography and life-history evolution in plant and animals. As I couldn’t possible fit all the ideas worth sharing from the fields of demography and life-history evolution into an eleven-minute entertainment talk I focused on research related to the variation of maximum lifespan across vertebrates. In particular, I discussed research originating from my PhD on trying to understand why some species seem to live far longer than we would normally expect and how their ecology may be related to this (http://rspb.royalsocietypublishing.org/content/281/1784/20140298).

My approach is that it is the species that are found at the extremes of nature that can often be the most informative. Whales tell us about the limits of size, cheetahs the limits of speed and ants the power of cooperative behavior. However, it is not always the Guinness book of record style species that are the most interesting, for when it comes to understanding aging it is oddball creatures such as the bats and the naked mole rat that are the unsightly stars of many aging studies. The reason for this interest is because these animals seem to have the inside scoop on the elixir of youth with both bats (>40 years max) and naked mole rats (>30 years max) living an order of magnitude longer than expected for their size.

From commons.wikimedia.org

Despite this we still have little idea of not just how, but why these species have such life-history strategies. This is important not simple with regards to understanding life-history evolution, but because researchers are beginning to target species and genes with potential links to the abilities that keep aging at bay. For example, the extreme lifespan of naked mole rats has been touted as being the result of the reduced danger associated with its subterranean lifestyle. This has led researches to target species and genes associated with with living underground, such as genes related to their stretchy skin, as these are to thought to be themselves linked with reducing sources of age related mortality such as cancers. However, the role of subterranean living in increasing lifespan is still debated, leaving such a targeted approach in danger of missing the mark in other scenarios.

My idea worth sharing is that we should not just find these unusual species but also understand what evolutionary and ecological drivers shaped these species. With the help of more detailed datasets like COMADRE and COMPADRE we can begin to understand the evolutionary and ecological drivers that lead to species at the extremes of life history evolution. We should aim to not just know who the oddball stars of life-history studies should be, but why they really are stars.

Author: Kevin Healy

Contact: @healyke

19/11/201519/11/2015

3 years as a PhD student

I arrived in Ireland October 2012 with the purpose of undertaking a PhD supervised by Natalie Cooper on Primates evolution. Looking back, the start of the whole endeavour seemed really stressful to me (new country, new customs, new language) and the project just as frightening (what do I do?, where do I start?, will I be able to do it?)… What happened after was way below my expectations: these three years were anything but stressful and frightening!

OK, even though not everything went smoothly and it had to take the best of the personalities (that are thankfully common sights in Trinity College’s Zoology Department) for dealing with some ups and downs, here is my top 5 list of personal thoughts that always improved the two aspects of my PhD: the working aspect (the research) and the “social” aspect (feeling relaxed and enjoying it).

Be ready to change your PhD

As I mentioned in the first line, my PhD was supposed to be on Primates evolution. In the end, the world “Primates” is mentioned only once (and that is, buried in a sentence about several other mammalian orders). Of course, sometimes the PhD is a Long Quiet River if everything goes well and you keep your highest interest in the original topic. However, sometimes it changes completely! And this should never be a problem! The PhD should be allowed to evolve just as much as yourself (or more pragmatically: your field) evolves into these three or four years.

Failure happens to everyone

Another major part about the PhD (and about the scientific endeavour itself!) is that it will fail. More or less often and more or less dramatically in each case but failure should just be part of the process. As a early career researcher, you can learn a lot from the mistakes and the success of others. However, I found that there is nothing much more personally instructing than the trial and error. I already mentioned how my biggest PhD disaster led to my most positive development.

Stay open-minded and curious

Writing the thesis or even just doing the lab/computer work for the PhD can narrow your mind and highly decrease your sanity. I found that the best way to avoid that was to try as much as possible to make the PhD only priority number two and put all the other things (seminars, meeting speakers, chatting/helping colleagues, etc…) before it. It has two advantages for the PhD: (1) you don’t work on it 24/7 and (2) everything you learn outside of it will actually be super useful for the PhD. In the Zoology Derpartment, we were only a couple of people doing macroevolution surrounded by ecologists. Yet, I think my work benefited heavily from the influence from these people.

Don’t rush

One thing I found nice with the PhD is that before you even start – before day one! – you already know the final deadline. OK, at day one, the handing in date seems far away (3 or 4 years away actually!) but that leaves you plenty of time for doing awesome research, writing it down as papers/chapters (and even trying to publish them before the deadline) and going to the pub or to other non-PhD recreational events…

Chat with your colleagues

Finally, I found that I gained so much just by chatting with my colleagues. And by colleagues I mean my fellow PhD students of course but also with the post-docs and the staff. I always found a long term benefit to both PhD aspects, whether it was talking about the latests video games during working time (I’m not only looking at you @yodacomplex) or having heated debates about species selection during coffee time.

I know much of these tips worked for me but might not apply to other people. In the end their is only one ultimate tip: make your PhD a hell of a good time!

author: Thomas Guillerme, @TGuillerme

Photo Credit: Thomas Guillerme

04/11/201505/04/2019

A Nobel Pursuit

Splitting the atom, unlocking the secrets of radiation, or even leading a peaceful civil rights movement.

I grew up knowing that these were the sorts of achievements that earn you a gold medal and an invitation to Sweden in mid-December. I have since learned that the annual ceremony held in honour of Alfred Nobel hasn’t always been awarded to the most deserving candidate, and that sometimes the winners simply stumbled upon a discovery that changed the world. This was not the case with the 2015 Nobel prize for Physiology and Medicine. Continue reading “A Nobel Pursuit”

08/05/201505/05/2015

Looks can be deceiving

We are all taught not to judge a book by its cover, it’s what inside that counts. Our new paper published in PeerJ shows that the same is true for tenrecs.

These cute Madagascar natives are often used as an example of a mammal family with high morphological diversity. It’s easy to see why: there are tenrecs which resemble shrews, moles, hedgehogs and even otters. These differences are even more remarkable when you consider that tenrecs are more closely related to elephants and aardvarks than they are to any of the small, “insectivore” mammals. One of only four native mammal clades in Madagascar, it appears that tenrecs have undergone an adaptive radiation to fill otherwise vacant, small mammal niches, evolving convergent similarities to other groups in the process.

Tenrecs are clearly very diverse in their appearance. However, prior to our study, no one had tested whether this apparently high diversity was more than skin deep. We tested whether tenrecs were more morphologically diverse than their closest relatives, the golden moles.

We measured the morphology of tenrec skulls and compared their diversity to the shape of golden mole skulls. This meant spending hours poking around the collections of natural history museums and many more hours placing landmarks on skull pictures for 2D geometric morphometrics analyses (Spotify was my friend!)

Pictures of an otter shrew tenrec (Potamogale velox) skull showing that landmarks (points) and semilandmarks (curves) that we used to summarise skull shape. See the paper for more information. — Pictures of an otter shrew tenrec (*Potamogale velox*) skull showing that landmarks (points) and semilandmarks (curves) that we used to summarise skull shape. See the paper for more information.

Tenrecs occupy a wider range of ecological niches (fossorial, arboreal, terrestrial and aquatic) than golden moles so we expected that tenrecs would be more morphologically diverse than their cousins. However, we found that tenrec skulls only have more diverse shapes than golden moles when we compared them in lateral (sideways) view but not dorsal or ventral views. These results show the importance of measuring morphology in many different views to gain a more complete understanding of overall morphological diversity.

The tenrec family includes species which convergently resemble many other, un-related small mammals. However, most tenrecs (19 out of the 31 tenrec species in our analysis) belong to the shrew-like Microgale tenrec genus. So, although many people tend to focus on the strange and unusual species (such as the otter shrew, hedgehog tenrec or the bizarre lowland streaked tenrec), most tenrecs are small, shrewy-type creatures that look very similar.

We tested whether the similarities among the Microgale tenrecs might be masking higher morphological diversity in the rest of the family. We repeated our analyses to compare the diversity of golden mole skulls to a sub-set of the tenrec family (including just 5 of the 19 Microgale species). In this case, tenrec skulls were more morphologically diverse than golden mole skulls in all comparisons (skulls in dorsal, ventral and lateral view).

Overall, our results indicate that, while there are clear physical differences among tenrec family members, the majority of tenrecs are quite morphologically similar to each other so morphological diversity in the family as a whole is not as big as it first appears. Of course comparing skull diversity is just one aspect of overall morphology – analysing the shape of other traits such as limbs could yield different results – but our study represents the first step towards a greater understanding of the ecological and evolutionary diversity of tenrecs.

It’s also testimony to the fact that you should never judge a tenrec by its cover.

Author: Sive Finlay, @SiveFinlay

21/11/2014

Internal Affairs

So for various reasons, one of which was being unsure of whether a PhD was for me, I found myself asking to work as an Intern with the good people in the Zoology Department at TCD. To give you a bit of background, I am a Zoology graduate with an MSc in Marine Biology, so not just some random bloke who happens to like animals and fancied chancing his arm. Anyway, I approached Dr. Ian Donohue whose research group interested me and thus began a 9 month Internship as a Research Assistant.

With a little trepidation and a great deal of excitement I began my stint as a minion with a site inspection for a proposed project looking at community structure in a rocky shore ecosystem. (Note to anyone who is interested in rocky shore ecology, I would advise not severely spraining your ankle the day before, it’s incredibly frustrating trying to navigate a boulder field while being unable to walk). Over the following weeks, I assisted in the field work required to set the project up. I thoroughly enjoy being outdoors so this suited me perfectly, although I must admit how lucky we were weather wise, it rained on only one day of 9 or 10 days we had out there so perhaps my love of the outdoors will diminish as soon as I’ve encountered some proper Irish weather!! Since then I have been involved in a range of projects from pilot studies on coevolution and trophic complexity of bacterial communities to feeding and respiration rates in Mysid shrimp, encompassing a range of laboratory and field techniques.

The learning doesn’t stop at the practical side of science either, merely by being involved in a working department I have learned more in the last 7 or 8 months about the ways of forging a career in science than I have done in my entire career to date. Our weekly journal club, NERD club was a bit of a revelation if I’m honest. Seeing how a collective of brilliant minds can come together and interact to assist with, develop and fine tune current and future work was an eye opener. It’s also an extremely beneficial way of encompassing different working groups/departments. The sharing of ideas, new techniques and sometimes just a different perspective can lead to a well-rounded project and/or person and is something I would definitely recommend in any institution.

I’ve also begun to build a network, something crucial to succeeding in science (and any workplace I guess!), and definitely not one of my strongest attributes. I was fortunate enough to attend the BES Macroecology conference in Nottingham in July and to display our work to the public during the Discover Research event in September, both of which were thoroughly enjoyable and valuable to furthering my development. I am an avid supporter of outreach programmes so to participate in what was an extremely successful night was most rewarding.

To anyone who is in a similar position to the one I was I would highly recommend contacting a Professor or otherwise and asking is there a job you can do for them. If like me, you are willing to do it for nothing other than your own benefit then there is no reason why they would not accept the offer. I have learned so much during my time here, added considerably to my skill set and most of all I now know that a) I would like to continue to work in an academic environment and b) that I am fully capable of doing a PhD. Whether I do or not depends on a number of factors, but that is for another day.

Author: Alain Finn, alfinn@tcd.ie, @finchyirl

Image Credit: http://nassauso.com/internal-affairs/, https://twitter.com/DM_Minions

07/11/201406/11/2014

A Spark of Science

Why are some snakes more venomous than others? When did plate tectonics begin? What geological mysteries await our discovery on Mars? How do organisms build their own bodies? How do businesses manage biodiversity?

These are just some of the interesting and diverse Lightning Talks which were presented at a recent event in the School of Natural Sciences. Researchers from the disciplines of Botany, Geology, Geography and Zoology had just two minutes to present their work to colleagues and friends. The strict format created an interesting evening filled with bite-size chunks of science.

We were very lucky to have a great judging panel comprised of Professor Fraser Mitchell (Head of School), Donal Daly (Senior Scientific Officer at the EPA), Thomas Deane (Press Officer for Engineering, Maths and Science), Aoibheann Bird (Education and Outreach manager, Insight Centre for Data Analytics) and Diane McSweeney (Education team at the Science Gallery). The speakers were judged on their content, delivery and use of props. Prizes were kindly sponsored by the Trinity Foundation, the Science Gallery, the Botanical Society of Britain and Ireland and the Graduate Student’s Union.

Botany PhD student, Brian Murphy, won first prize for his talk “A hidden force that will feed the world”. Brian’s research focuses on endophytes: fungi that live in the roots of plants that have great commercial potential for increasing crop yield in an eco-friendly and sustainable way. There were two runner up prizes: Kevin Healy for his talk on the evolution of snake venom (which also featured as part of the Science Gallery’s recent event, Dead Beats) and I won a prize for story about how looks can be deceiving in tenrecs. Other prize winners from the evening included Alwynne McGeever, Hannah Hamilton, Gary O’Sullivan and Mike Williams.

It was a great evening filled with lots of interesting talks and a good chance to find out about the diverse research in the School. Thanks to the fantastic organising committee: Jane Stout, Maria Long, Frances Leogue, Rachel Kavanagh, Tara Kelly, Clare Stead and Alwynne McGeever for making everything run so smoothly!

Videos of all the prizewinning talks can be found on the School’s YouTube channel.

Author: Sive Finlay, @SiveFinlay

Photo credit: wikimedia commons

24/10/201423/10/2014

Bird Feeders

It’s coming up to winter so people will be conscious that our garden birds need a helping hand to get through the cold months. Bird feeders will be stocked, bread served up and water dished out. In the UK alone, almost half of households provide supplementary food for birds throughout the year. And although songbirds are usually the species that come to mind when we think of provisioning food the same principle can apply to more exotic birds, notably vultures. Indeed conservationists have supplied extra food to these scavengers for decades. Instead of bread or berries, a carcass is left out for the vultures to feed on. A recent paper of ours advocates this technique for a population of African White-backed Vultures in Swaziland.

This country is home to the densest breeding population of this species so we should do our best to conserve them given the huge declines suffered by vultures throughout the Old World. In the paper we showed times when there isn’t enough food in Swaziland to feed the whole population which means the birds are forced to forage farther afield, most likely in South Africa. On the face of it this doesn’t seem problematic because South Africa has huge populations of herbivores which could supply carcasses to vultures. But the birds must fly over unprotected areas as well. This increases their chances that they’ll encounter a poisoned carcass, perhaps set out by a farmer to kill the terrestrial carnivores harassing his livestock.

It’s well known that vultures are particularly sensitive to poisons, especially NSAIDs. Their group foraging behaviour makes them even more susceptible too, the discovery of a carcass by one individual will bring in the rest of the soaring birds in visual range. The hope with creating vulture restaurants is the birds will focus on foraging for carrion in Swaziland, minimising the risk of poisoning.

Yet there are well known problems with supplying supplementary food for animals in general. They may act as an ecological trap for instance, drawing the birds into an area only for the fickle humans to stop the supply of food. Carrion is an unpredictable resource so vultures forage in a characteristic way to improve their chance of encountering it. If food is supplied in a predicable way there is a fear we may disrupt these behaviours. Another recently realised danger in providing supplementary food is that it can attract unwanted guests. Sites tailor made for vultures in South Africa were shown to draw in jackals and hyenas.

Given these issues practitioners need to think carefully about how they provide food. Perhaps the best approach is a series of sites supplying food at random which would best represent the distribution of naturally occurring carrion.

Author: Adam Kane, @P1zPalu, kanead[at]tcd.ie

Photo credit: Munir Virani