longevity Archives - EcoEvo@TCD

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

28/04/201406/04/2019

Dying without wings: Part II

Last week our newest EcoEvo@TCD paper came out in PRSB (it will be Open Access soon but currently it’s behind a pay wall – feel free to email me for a copy in the meantime. Code for the multiple PGLS models can be found here). This paper is exciting for me for two reasons – firstly because the science is really cool and secondly because of how it came about. In a previous post I explained the results of the paper. Today I want to focus on how it came about. Continue reading “Dying without wings: Part II”

25/04/201406/04/2019

Dying without wings* Part I

Last week our newest EcoEvo@TCD paper came out in PRSB (it will be Open Access soon but currently it’s behind a pay wall – feel free to email me for a copy in the meantime. Also code to fit multiple PGLS models can be found here). This paper is exciting for me for two reasons – firstly because the science is really cool, and secondly because of how it came about. Today I want to focus on the paper itself, and in my next post I will explain how this collaborative project started. Continue reading “Dying without wings* Part I”

26/04/2013

School of Natural Sciences Postgraduate Symposium: Part 3/4

On the 15^th and 16^th April we had one of my favourite events at Trinity College Dublin: the annual School of Natural Sciences Postgraduate Symposium. Over the course of two days many of our PhD students presented their work to the School. We also had two amazing plenary talks from Dr Nick Isaac (CEH) and Professor Jennifer McElwain (UCD). 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!

Karen Loxton [@LoxtonKaren]: Parasite lost: Helminth parasites in the invasive bank vole in Ireland.

Invasive species are a major cause of biodiversity decline throughout the world. Determining why some species become invasive when introduced to a new environment is therefore of great importance. One hypotheses is that invasives escape their native parasites and are ‘released’ from the effects of parasitism. This project looked at the intestinal helminth parasites of the invasive bank vole to determine if it is less parasitised than in its native ranges.

Kevin Healy [@healyke]: Digging how you wing it! Extrinsic mortality and longevity in volant and fossorial endotherms. *Highly commended*

Longevity is a fundamental life history trait that exhibits considerable variation among species. While longevity strongly correlates with body size many species live either far longer, or indeed shorter, than expected. Classical life history theory predicts that species that experience high extrinsic mortality will, on average, evolve shorter lifespans. We tested using phylogenetic comparative methods in birds and mammals whether species that either possess abilities or live in environments that reduce predation display longer lifespans. Our results showed that as predicted traits such as volancy, fossoriality and foraging in arboreal environments are associated with long-lived species.

Louise Esmonde: Plant selection for use in a submerged macrophyte vegetation (SAV) wetland under temperate conditions.

Constructed wetlands are seen as a sustainable and low carbon alternative to conventional wastewater treatment solutions. Submerged Aquatic Vegetation (SAV) wetlands utilize the ability of submerged macrophytes to remove nutrients and metals from the water phase to treat wastewater. This study uses the relative growth rates (RGR) of a number of submerged macrophyte species as an aid in selecting the best species for use in a SAV wetland. So far the RGR of the submerged macrophyte species Myriophyllum spicatum, Elodea canadensis and Ceratophyllum demersum have been measured. RGR was found to be in the order: E. canadensis > M. spicatum for planted specimens and M. spicatum > E. canadensis > C. demersum for unplanted specimens. Research is on-going into the treatment potential of these species in terms of nutrient and metal removal from wastewaters.

Melinda Lyons: Petrified plants – the ecology of lime-rich springs

Petrifying springs are intriguing ecological and hydrogeological features with extreme chemical conditions in which specialised plant species thrive. They deposit ‘tufa’, a porous rock, on the ground surface and on plants where lime-rich spring water emerges. Recent measurements of tufa accumulation show surprisingly rapid growth rates. This distinctive habitat (a priority habitat in Annex I of the Habitats Directive) is being investigated in Ireland for the first time. Analysis of relevé data indicates that different subtypes occur depending on topographical settings. Some examples are of particularly high conservation value, most notably those on the Benbulbin Range of Counties Sligo and Leitrim. The habitat is vulnerable to changes in water flow and quality, land use practices and visitor pressures.

Hanan Elshelmani: MicroRNA profiling in serum of Age-Related Macular Degeneration patients

Age-related macular degeneration (AMD) is a common condition causing a progressive visual impairment, leading to irreversible blindness. This condition is characterised by loss of central vision attributed to degenerative and neovascular changes that occur in the neural retina and the underlying choroid. In what we believe to be the first study of its kind, here we aimed to establish if circulating miRNAs may exist which are associated with AMD and so may have relevance as novel test for rapid screening, early diagnosis; disease sub-typing; and/or treatment selection for AMD. Results: Unsupervised hierarchical clustering (performed using dChip software) indicated that AMD specimens have a different miRNA profile compared to that of healthy controls. Overall 157, 207, 190 miRNAs were detected in control, neovascular and atrophic respectively. 56 and 11 miRNAs, respectively, were found to be detectable at significantly higher levels in serum specimens from neovascular and atrophic patients compared to control sera. Interestingly, only 5 differentially-expressed miRNAs overlapped between atrophic and neovascular patient groups; suggesting biomarker specificity for different types of this condition.

Patricia Coughlan: The phylogenetics of paclitaxel biosynthesis genes in Taxus baccata, Taxus hybrids and allies

Taxus baccata, more commonly known as the Irish Yew, is a natural producer of Paclitaxel. Bristol Myers Squibb developed an effective anti-cancer drug from Paclitaxel and gave it the trade name Taxol. Taxol is used to treat ovarian, breast and lung cancer. This project will develop molecular primers to amplify and study the genes involved in the Taxol biosynthetic pathway, and take a phylogenetic approach to discover which genes are more important for paclitaxel production. More specifically, it will discover variation in these genes between Taxus baccata and Taxus hybrids such as Taxus xmedia.

08/10/201218/02/2019

Is island life easier?

CG77 — Lemon-bellied White-eye (Zosterops chloris)

For over 10 years we have been making regular visits to islands in the Sulawesi region of Indonesia. We trap birds on these islands, collecting morphometric data. Each bird we trap is measured, marked with a plastic ring and released. As our dataset grows we gain more insight into the lives of the birds on these islands.

In 2007 and 2010 we visited the island of Kaledupa in the Wakatobi archipelago. In 2010 we made a point of revisiting all of the sites we had trapped at in 2007. This gave us an opportunity to look for the birds we had originally caught in 2007. Continue reading “Is island life easier?”