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Archive for July, 2014

Predicting Extinction Risk:
The Importance of Life History and Demography

By Claire Asher, on 28 July 2014

The changing climate is no longer simply a concern for the future, it is a reality. Understanding how the biodiversity that we share our planet with will respond to climate change is a key step in developing long-term strategies to conserve it. Recent research by UCL CBER’s Dr Richard Pearson identifies the key characteristics that are likely to influence extinction risk due to climate change, and shows that existing conservation indicators such as the IUCN red list may contain the data necessary to make these predictions.

Human activities have been negatively impacting biodiversity for centuries, and conservationists have developed a number of different indicator lists which attempt to classify species’ extinction risk. However, these lists were created to measure human impacts such as as habitat loss, hunting and introduction of invasive species. These impacts will continue to be a major issue for biodiversity, but may be dwarfed in the future as climate change takes hold. Can the indices and data we already have be used to predict extinction risk from climate change? Or does climate change represent a new type of threat, needing new indices?

Studies have previously identified the ecological and biological traits that are characteristic of threatened or declining species. However, it is not clear how well these traits predict the future risk of climate-induced extinction. In February this year, GEE’s Dr Richard Pearson, in collaboration with colleagues at the American Museum of Natural History, Stony Brook University and the University of Adelaide, published a paper in Nature which attempted to address these questions. Most studies that have considered the impact of climate change on species’ extinctions have attempted to predict changes in the distribution of suitable habitats and measure extinction risk in terms of whether the species is likely to be able to find habitat to live in. However, such studies rarely consider how a species’ traits such as life history and spatial characteristics will influence their ability to persist through changes in climate. In this study, Pearson and colleagues coupled ecological niche models with demographic models, and developed a generic life history method to estimate extinction risk over the coming century.

Modelling Extinction
The authors then tested their models on ecological and spatial traits for 36 reptile and amphibian species in the USA. Using commonly available life history variables, they found that their models could accurately predict extinction risk between 2000 and 2010. They then utilised the same traits and models to predict future extinction risk under two climate models – a high emissions scenario and a policy scenario aimed at curbing emissions. Average extinction risk for the 36 species studied was 28% under the high emissions scenario, dropping to 23% under strict policy intervention. This seems like a very small difference for a significant intervention – it’s important to note that the same estimates indicated an average extinction risk of just 1% in the absence of any climate change at all.

One of the most important determinants of extinction risk in reptiles and amphibians was occupied area, which represents the range of climatic and habitat conditions the species can survive in. Species with a larger occupied area tended to be more robust to climate change, presumably because they are already adapted to a wider range of habitats and climates. Other key variables influencing extinction risk include population size and generation length. In many cases, traits interacted to determine species risk, for example extinction risk was strongly influenced by interactions between occupied area and generation length. Including many different traits can therefore greatly improve the accuracy of predictions. Recent trends tended to be less informative than spatial, demographic and life history traits, particularly under the high emissions scenario, suggesting that the impacts of climate change we have observed so far are likely to become less and less relevant as climate change accelerates.

The majority of variables that showed a significant impact on extinction risk are already included in major conservation assessments and indices, meaning that data and monitoring programs already in place may be better at predicting extinction risk under climate change than we might have expected. Climate change may not be fundamentally different from other human threats such as habitat loss and hunting, at least in terms of our ability to assess extinction risk. Conservation initiatives should focus on species who currently occupy a small and declining area and have a small population size. Regardless of the policy future, conservation actions will need to consider and account for climate change if they are to prove effective.

Original Article:

() Life History and Spatial Traits Predict Extinction Risk Due to Climate Change Nature

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This research was made possible by funding from the National Aeronautics and Space Administration (NASA) and the Australian Research Council

It Pays to Be Different:
Evolutionary Distinctiveness and Conservation Priorities

By Claire Asher, on 15 July 2014

The world is currently experiencing an extinction crisis. A mass extinction on a scale not seen since the dinosaurs. While conservationists work tirelessly to try and protect the World’s biodiversity, it will not be possible to save everything, and it is important to focus conservation efforts intelligently. Evolutionary distinctiveness is a measure of how isolated a species is on it’s family tree – how long ago it split off from its nearest living relative. A recent paper co-authored by UCL GEE’s Dr David Redding, published in Current Biology, assessed how effective evolutionary distinctiveness is a tool for identifying bird species of conservation priority. Current conservation efforts are missing some of the most evolutionarily distinct species.

Evolutionary distinctiveness (ED) is measured as the distance along the evolutionary tree from one species to it’s nearest relative. It can be used as a measure of how much evolutionary ‘information’ would be lost if this species were to become extinct. We have good estimates of these distances for birds as we have been able to put dates on the evolutionary tree based on fossil records and molecular data. A recent analysis of nearly 10,000 known bird species, by researchers at Yale University, Imperial College London, University of Sheffield, Simon Fraser University, University of Tasmania and University College London, showed some patterns we might have expected, for example, evolutionary distinctiveness is highest in isolated regions (e.g. Australia, New Zealand and Madagascar) and regions with higher species richness tended to have more evolutionary distinct birds. However, there were also some unexpected results. For example, ED wasn’t strongly related to latitude, a pattern predicted by the idea that the tropics act as a ‘museum’ for ancient lineages, nor was ED related to a species’ range-size, which has previously been predicted theoretically.

Evolutionary distinctiveness showed little relationship with conservation status – some of the most threatened distinct species are found outside of biodiverse regions that are usually the target of conservation efforts. This means that, when we consider only species richness or total biodiversity to identify regions to conserve, we may be missing a great deal of evolutionary information. Instead, basing areas of conservation priority on the evolutionary distinctiveness of their flora and fauna may offer a more efficient and effective way to maximise the evolutionary variation we keep.

The paper also released the first formal list of ‘EDGE birds’ – EDGE stands for “Evolutionary Distinctive and Globally Endangered” and is a metric combining ED with the IUCN Red List. The list includes the Giant Ibis, the New Caledonian Owlet-Nightjar, the California Condor, the Kakapo, the Philippine Eagle, the Christmas Island Frigatebird and the Kagu, all of which are listed as either Critically Endangered or Endangered.

The most evolutionary distinct birds include both common species and rare species, both isolated and wildly distributed species, and are found in almost every environment on Earth. Current conservation efforts that focus on tropical regions with high species richness may be neglecting many evolutionary distinct species, whose extinction would represent the loss of a great deal of ‘evolutionary information’. Evolutionary distinctiveness could offer a powerful tool to supplement current criteria for identifying conservation priorities.

Original Article:

() Current Biology

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This research was made possible by funding from the Natural Environment Research Council (NERC), the Natural Sciences and Engineering Research Council (NSERC), the National Science Foundation, and the National Aeronautics and Space Administration (NASA)

Synthetic Biology and Conservation

By Claire Asher, on 7 July 2014

Synthetic biology, a hybrid between Engineering and Biology, is an emerging field of research promising to change the way we think about manufacturing, medicine, food production, and even conservation and sustainability. Oryx front cover
A review paper released this month in Oryx, authored by Dr Kent Redford, Professor William Adams, Dr Rob Carlson, Bertina Ceccarelli and CBER’s Professor Georgina Mace, discusses the possibilities and consequences of synthetic biology for biodiversity conservation. Synthetic biology aims to engineer the natural world to generate novel parts and systems that can be used to tackle real world problems such as genetic disease, food security, invasive species and climate change. It’s implications are far reaching, and although research in synthetic biology began decades ago, conservation biologists have only recently begun to take notice and appreciate it’s relevance to the conservation of biological diversity. A conference organised by the Wildlife Conservation Society in 2013 discussed the relationship between synthetic biology and conservation, and included speakers from both fields.

Finding Common Ground
It might be surprising to find that, despite a similar background in biological research, the shared knowledge and language of conservationists and synthetic biologists is relatively limited. Further, many synthetic biologists come from an engineering background, with little training in ecology. This can make communication between scientists in these fields more difficult, and may have slowed the pace at which synthetic biology has interfaced with conservation science. The two disciplines also employ different methods and think about nature in different ways. Synthetic biology is largely conducted within large, highly controlled laboratory conditions, whilst ecologists work on complex, interrelated natural systems with a major social and political component. Conservationists, working in a high-stakes field and learning from past mistakes, tend to be quite risk-averse in their practice of conservation, whilst synthetic biologists, working in a new science with much to gain from experimentation, tend to be more in favour of taking large risks. They may also have different outlooks on the future of biodiversity – conservations tend to be more pessimistic about the future, mourning past biodiversity loss, whilst synthetic biologists have an upbeat attitude, envisaging the applications of exciting research. Despite these (extremely generalised) differences, the conference revealed interest and excitement on both sides about the possibility of collaborating, and a mutual appreciation that the major challenges of the Anthropocene are human influences on climate, biodiversity and ecosystems. Finding practical, long-lasting and safe solutions to the plethora of challenges currently facing humanity, is of mutual interest.

Mitigating Risks and Maximising Benefits
The possible applications of synthetic biology to conservation are many. Synthetic biology might enable us to develop more efficient methods of energy production, freeing up habitat to recover. It could mitigate the effects of greenhouse gas emissions by releasing carbon-consuming algae. It could revive extinct species such as mammoths and dodos in a process known as ‘de-extinction’. It could engineer coral that is tolerant to increases in ocean temperature and acidity, conditions which are predicted to worsen under climate change. It could help to control or eradicate invasive species. It could restore degraded land and water for agriculture, sparing the need to destroy more natural habitat. It could even create pesticide- and parasite-resistant bees that can continue to pollinate our crops generations into the future.

However, he potential risks of synthetic biology to conservation are as many as the potential benefits. The effects of synthetic biology on conservation could be direct, (e.g. engineering resistant species), or they could be indirect (e.g. changes in land use). These effects could be negative, for example, if they lead to land use change of primary habitat as has been associated with GMOs and biofuels. They could also be positive, for example if they reduce the impact of human activities, allowing habitat to recover to its natural state. Synthetic biology might lead to unexpected impacts on ecosystem dynamics and risks the unintended escape of novel organisms into open ecosystems. Releasing synthetically engineered organisms into wild environments could alter ecosystems, reduce natural genetic variability or lead to hybridisation events that might display native flora and fauna, and generate new invasive species. Synthetic biology might also distract attention and funds from more traditional conservation efforts, whilst attracting protest from human rights and environmental organisations. Both conservationists and synthetic biologists are conscious of these potential risks, and are committed to careful consideration on a case-by-case basis. Not all synthetic biology is the same; some could be of huge potential benefit to conservation and sustainability whilst carrying minimal risks, and it is these that we should pursue.

Original Article:

() Oryx