The Great London [Search results for Biodiversity] 

Levels of global biodiversity loss may negatively impact on ecosystem function and the sustainability of human societies, according to UCL-led research.

"This is the first time we've quantified the effect of habitat loss on biodiversity globally in such detail and we've found that across most of the world biodiversity loss is no longer within the safe limit suggested by ecologists" explained lead researcher, Dr Tim Newbold from UCL and previously at UNEP-WCMC.

"We know biodiversity loss affects ecosystem function but how it does this is not entirely clear. What we do know is that in many parts of the world, we are approaching a situation where human intervention might be needed to sustain ecosystem function."

The team found that grasslands, savannas and shrublands were most affected by biodiversity loss, followed closely by many of the world's forests and woodlands. They say the ability of biodiversity in these areas to support key ecosystem functions such as growth of living organisms and nutrient cycling has become increasingly uncertain.

The study, published in >Science, led by researchers from UCL, the Natural History Museum and UNEP-WCMC, found that levels of biodiversity loss are so high that if left unchecked, they could undermine efforts towards long-term sustainable development.

For 58.1% of the world's land surface, which is home to 71.4% of the global population, the level of biodiversity loss is substantial enough to question the ability of ecosystems to support human societies. The loss is due to changes in land use and puts levels of biodiversity beyond the 'safe limit' recently proposed by the planetary boundaries -- an international framework that defines a safe operating space for humanity.

"It's worrying that land use has already pushed biodiversity below the level proposed as a safe limit," said Professor Andy Purvis of the Natural History Museum, London, who also worked on the study. "Decision-makers worry a lot about economic recessions, but an ecological recession could have even worse consequences -- and the biodiversity damage we've had means we're at risk of that happening. Until and unless we can bring biodiversity back up, we're playing ecological roulette."

The team used data from hundreds of scientists across the globe to analyse 2.38 million records for 39,123 species at 18,659 sites where are captured in the database of the PREDICTS project. The analyses were then applied to estimate how biodiversity in every square kilometre land has changed since before humans modified the habitat.

They found that biodiversity hotspots -- those that have seen habitat loss in the past but have a lot of species only found in that area -- are threatened, showing high levels of biodiversity decline. Other high biodiversity areas, such as Amazonia, which have seen no land use change have higher levels of biodiversity and more scope for proactive conservation.

"The greatest changes have happened in those places where most people live, which might affect physical and psychological wellbeing. To address this, we would have to preserve the remaining areas of natural vegetation and restore human-used lands," added Dr Newbold.

The team hope the results will be used to inform conservation policy, nationally and internationally, and to facilitate this, have made the maps from this paper and all of the underlying data publicly available.

Source: University College London - UCL [July 14, 2016]

A new study says that more than 17,000 marine species worldwide remain largely unprotected, with the U.S. among the bottom in supporting formal marine protected areas (MPAs) that could safeguard marine biodiversity.

The study, which is the first comprehensive assessment of protected areas coverage on marine life, appears in the international journal Scientific Reports. Authors include scientists from University of Queensland, the Australian Research Council Centre of Excellence for Environmental Decisions (CEED), UC Santa Barbara, the National Center for Ecological Analysis and Synthesis, Imperial College London and the Wildlife Conservation Society.

The authors looked at the ranges of some 17,348 species of marine life, including whales, sharks rays and fish, and found that 97.4 percent have less than 10 percent of their range represented in marine protected areas. Nations with the largest number of "gap species" or species whose range lie entirely outside of protected areas include the U.S., Canada, and Brazil.

Despite these dismal results, the authors say the study underscores opportunities to achieve goals set by the Convention on Biological Diversity to protect 10 percent of marine biodiversity by 2020. For example, the majority of species that were considered very poorly represented (less than two percent of their range found in marine protected areas) are found in exclusive economic zones. This suggests an important role for particular nations to better protect biodiversity.

"The process of establishing MPAs is not trivial as they impact livelihoods. It is essential that new MPAs protect biodiversity whilst minimizing negative social and economic impacts. The results of this study offer strategic guidance on where MPAs could be placed to better protect marine biodiversity." said the study's lead author Dr Carissa Klein of the University of Queensland and CEED.

The authors say that it is imperative that new MPAs are systematically identified and take into account what has already been protected in other places, in addition to socioeconomic costs of implementation, feasibility of success, other aspects driving biodiversity.

"The increase in the number MPAs in recent years is encouraging, but most of this increase has come from a few very large MPAs," said Dr. Ben Halpern of UC Santa Barbara and NCEAS. "Those very large MPAs provide important value, but they can be misleading in thinking that biodiversity is being well protected because of them. Species all around the planet need protection, not just those in some locations. Our results point out where the protection gaps exist."

Said co-author Dr. James Watson of WCS and the University of Queensland: "As most marine biodiversity remains extremely poorly represented, the task of implementing an effective network of MPAs is urgent. Achieving this goal is imperative for not just for nature but for humanity, as millions of people depend on marine biodiversity for important and valuable services."

Source: Wildlife Conservation Society [December 03, 2015]

Gaps in our information about biodiversity means we are at risk of focussing our conservation efforts in the wrong places.

New research from Newcastle University, UK, University College London (UCL) and the University of Queensland, Australia, highlights the uncertainty around our global biodiversity data because of the way we record species sightings.

The study explains how a lack of information about a species in a particular location doesn't necessarily mean it's not there and that recording when we don't see something is as important as recording when we do.

Changing the way we record data

Publishing their findings in the journal Biology Letters, the team say we need to change the way we record sightings -- or a lack of them -- so we can better prioritise our conservation efforts in light of the Convention on Biological Diversity.

Dr Phil McGowan, one of the study's authors and a Senior Lecturer in Biodiversity and Conservation at Newcastle University, said: "Where there is no recent biodiversity data from an area then we might assume a species is no longer found there, but there could be a number of other possible reasons for this lack of data. It could be that its habitat is inaccessible -- either geographically or due to human activity such as ongoing conflict -- or perhaps it's simply a case that no-one has been looking for it. Unless we know where people have looked for a particular species and not found it then we can't be confident that it's not there."

Galliformes and man

To test the research, the team used the rigorously compiled database of European and Asian Galliformes -- a group of birds which includes the pheasant, grouse and quail.

"Our long-standing love of the Galliformes goes back hundreds of years which means we have records that are likely to be much better than for other groups of animals or plants," explains Dr McGowan.

"Not only have these birds been hunted for food, but their spectacular colours made them valuable as trophies and to stock the private aviaries of the wealthy. In the late 1800s and the turn of the last century, the Galliformes were prized specimens in museum and private collections and today they are still a favourite with bird watchers."

Data absent from 40% of the study area

Analysing 153,150 records dating from 1727 to 2008 and covering an area from the UK to Siberia and down to Indonesia, the team found that after 1980, there was no available data at 40% of the locations where Galliformes had previously been present.

The study suggests two possible scenarios.

Dr Elizabeth Boakes, the study's lead author and a teaching fellow at University College London, said: "We have no evidence of populations existing past 1980 in 40% of our locations. However, absence of evidence is not evidence of absence. One scenario is that populations have been lost from these areas, probably due to hunting or habitat loss. The other scenario is that the species are still locally present but that nobody has been to look for them. Our study shows that which scenario you choose to believe makes a huge difference to measures used in conservation priority-setting such as species richness and geographic range. It's important that we make the right call and that means a big shake up in the way we currently monitor biodiversity. We need to record what we don't see as well as what we do see and we need to be recording across much wider areas."

Meeting international targets

Involving 192 countries and the EU, the Convention on Biological Diversity is dedicated to promoting sustainable development.

The goals include the Strategic Plan for Biodiversity which says we must at least halve and, where feasible, bring close to zero the rate of loss of natural habitats, including forests, and halt extinction of those species we know to be under threat.

"In order to start meeting these goals we must first understand exactly which organisms are close to extinction and need prioritising in order to meet this target," explains Dr McGowan, who is Co-chair of IUCN Species Survival Commission's Policy Subcommittee and a member of its Strategic Conservation Planning Subcommittee.

"The IUCN Red List of Threatened Species is a good starting point but as our research shows, it's only as accurate as the data that's been collected. Going forward, we need to make sure we are recording when we've not seen something just as much as when we do and that's where keen and informed members of the public -- such as bird watching groups -- could really help us."

Source: Newcastle University [March 08, 2016]

Planet Earth may contain millions fewer species than previously thought and estimates are converging, according to research led by Griffith University.

In a paper published by the journal Proceedings of the National Academy of Sciences (PNAS), Professor Nigel Stork of Griffith’s Environmental Futures Research Institute reveals findings that narrow global species estimates for beetles, insects and terrestrial arthropods.

The research features an entirely new method of species calculation derived from samples of beetles from the comprehensive collection at London’s Natural History Museum.

“It has been said we don’t know to the nearest order of magnitude just how many species with which we share the planet. Some say it could be as low as two million; others suggest up to 100 million,” says Professor Stork.

“By narrowing down how many species exist within the largest group – the insects and other arthropods — we are now in a position to try to improve estimates for all species, including plants, fungi and vertebrates.

“Understanding how many species there are and how many there might have been is critical to understanding how much humans have impacted biodiversity and whether we are at the start of, or even in the middle of, an extinction crisis.”

About 25 per cent of all species that have been described are beetles. However, when combined with other insects the figure climbs to more than half of all described and named species on Earth.

New method of estimation

For this reason, Professor Stork and his colleagues focused on asking how many species of beetles and insects there actually are, in the process applying a new method of estimation arising from a tendency for larger species of British beetles to be described before smaller species.

“Because of the global spread of major beetle lineages, we made the assumption that the size distribution of the very well known British beetles might be similar to that of beetles worldwide,” says Professor Stork.

“So, if we could get a measurement of the body sizes of the beetles from around the world, we might be able to plot where these fitted in time against the British beetles.”

After measuring a sample from the Natural History Museum’s worldwide collection of beetles, Professor Stork compared the mean body size with the changing body sizes of British beetles to reveal that roughly 10 per cent of the world’s beetles have been named and described.

This figure sheds intriguing light on previous estimates of global species richness.

In the 1980s, there were just two methods of estimating species. In the case of beetles, these gave a mean of 17.5 million species and a range of 4.9-40.7 million. For all terrestrial arthropods, the mean was 36.8 million and a range of 7-80 million.

However, the new research shows that four current methods of estimation – dating from 2001 onwards — suggest much lower figures, namely a mean of 1.5 million for beetles (range 0.9-2.1 million) and 6.8 million for terrestrial arthropods (range 5.9-7.8 million).

“While all methods of estimating global species richness make assumptions, what is important here is that four largely unrelated methods, including the new body size method, produce similar estimates,” says Professor Stork.

“With estimates converging in this way, this suggests we are closer to finding the real numbers than before.

“It also means we can improve regional species richness. For Australian fauna and flora, for example, we should be able to make better estimates of just how many species there are and which groups need more taxonomic attention.”

Diversity of life

Professor Ian Owens, Director of Science at the Natural History Museum, says this research is a great example of how natural history collections support high-impact scientific research that addresses challenging questions such as the diversity of life.

“The Natural History Museum’s beetle collection is one of the most important and extensive in the world, so I’m delighted that it has played such a fundamental part in this study that uses a novel approach to estimating how many species of beetle exist,” says Professor Owens.

“The results are very exciting and are a big step forward to establishing a baseline for biodiversity.”

Meanwhile, co-author of the PNAS paper — the University of Melbourne’s Associate Professor Andrew Hamilton – says efforts to come up with new or modified ways of resolving how many species exist are beginning to prove fruitful.

Professor Stork says the research has important conservation ramifications.

“Success in planning for conservation and adopting remedial management actions can only be achieved if we know what species there are, how many need protection and where,” he says. “Otherwise, we have no baseline against which to measure our successes.

“Furthermore, it is arguably not only the final number of species that is important, but what we discover about biodiversity in the process.

“The degree to which we can or cannot accurately estimate the number of species or the scale of organismal diversity on Earth is a measure of our ignorance in understanding the ecological and evolutionary forces that create and maintain the biodiversity on our planet.

“Attacking this question also drives scientific enquiry and is of public interest. Society expects science to know what species exist on Earth, as it expects science to discover nuclear particles and molecules.

“These discoveries open doors to more utilitarian interests.”

Source: Griffith University [June 02, 2015]

A new and more dangerous phase of impacts on the world's remaining tropical forests is emerging, threatening to simplify the world's most diverse ecosystem including mass species loss, according to new UCL-led research published today in Science.

The impact of humans on these areas has been increasing for millennia and today more than three-quarters of the world's remaining tropical forests have been degraded by human actions.

The scientists identified three prior phases of expanding impacts, the first when hunter-gatherers moved into tropical forests and the second following the emergence of tropical agriculture, some 6,000 years ago. Under both, the overall health of tropical forests was maintained.

Today, we live in the third phase, marked by much greater impacts, with distant decision-makers directing how land is used, including permanent intensive agriculture, often for soybeans or palm oil, frontier industrial logging for timber export, cross-continental species invasions, and early climate change impacts. The scientists term this phase the era of 'Global Integration', affecting even the most remote areas.

Lead author, tropical forest expert Dr Simon Lewis (UCL Geography and University of Leeds) said: "Earth has lost 100 million hectares of tropical forest over the last 30 years, mostly to agricultural developments. Few people think about how intertwined with tropical forests we all are. Many foodstuffs include palm oil which comes from once pristine Asian tropical forest, while remaining intact forests are buffering the rate of climate change by absorbing about a billion tonnes of carbon each year."

Current trends look set to intensify without major policy changes, as global food demand is projected to double, over 25 million kilometres of road are predicted to be built by 2050, and climate change intensifies, ushering in a new phase of human dominance of tropical forests.

Dr Lewis added: "I fear a global simplification of the world's most complex forests. Deforestation, logging and road building all create fragmented patches of forest. However, as the climate rapidly changes the plants and animals living in the rainforest will need to move to continue to live within their ecological tolerances. How will they move? This is a recipe for the mass extinction of tropical forest species this century.

"What is needed are unbroken areas of forest that link today's core tropical regions with forest areas about 4 degrees cooler, so as temperatures rise and rainfall patterns change species have a better chance of surviving rapid 21st century climate change. We need to bring conservation in line with the reality of climate change."

The authors note that while deforestation and degradation continue, more optimistically, logged forest retains many environmental benefits, and marginal agricultural lands are being abandoned, which can return back to forest.

Dr David Edwards (University of Sheffield), co-author of the study, said: "Much biodiversity still remains in selectively logged forests, and can recover in secondary forests that grow on abandoned farmland. There is abundant potential to incorporate these forests into global plans to make tropical biodiversity climate change ready.

"Despite their value for biodiversity, logged-over and old secondary forests are frequently threatened by conversion to species-poor agricultural plantations. We urgently need to protect these human-impacted forests, especially in regions such as Southeast Asia where almost nowhere is left undegraded."

A suite of policy measures can help tropical forests survive, including giving forest dwellers formal collective legal rights over their land, which previous studies have shown is one of the best ways of preserving forests. A study of 292 protected areas in Amazonia showed that indigenous reserves were the most effective at avoiding deforestation in high pressure areas.

Most of the financial benefits of logging and plantation agriculture, such as palm oil, flow out of the forests. Ensuring local people have collective long-term rights over their lands would mean that benefits flowing from forest lands accrue to local people. This can provide the beginnings of programs of 'development without destruction', tackling poverty while maintaining forests. This, the authors argue, provides human rights and conservation win-wins.

Dr Lewis added: "With long-term certainty of tenure people can plan, maintaining forests while investing in improving agricultural productivity without expanding into forested lands. Forest dwellers won't be perfect managers of forests, but they won't look for a quick profit and then move on, as big businesses often do.

"This is a pivotal year for the global environment. There are some good signs for the world's tropical forests, with the UN New York Declaration on Forests agreeing to not only halt deforestation, but also restore 150 million hectares of forest. However, there are ominous signs too, with the palm oil industry having driven the world's highest deforestation rates in South East Asia now gearing up to repeat this process across Africa.

"The Paris climate change talks in December are doubly important for forests and forest communities. The levels of emission cuts will be a critical factor in determining how many tropical forest plants and animals go extinct over the coming decades and centuries. The agreements on reducing deforestation, including durable finance, will be pivotal. The final test will be whether some funds for adaptation will include land-use planning to retain forest connectivity as the climate rapidly changes."

Source: University College London [August 24, 2015]

Using a technique that can tell if a species has passed by from just a sample of water, scientists are developing new ways to assess ecosystems.

All animals shed fragments of DNA as they go about their lives – in faeces, mucous, sperm and eggs, shed skin, hair and, eventually, their carcasses.

These traces of genetic material can persist in the environment for some time – a matter of weeks in water and up to a few centuries in soil. With new, more sensitive DNA amplification and sequencing techniques, scientists can collect and analyse these fragments in water and soil samples and identify individual species that have passed by.

One area where environmental DNA, or eDNA, is finding practical use is in environmental assessments, for example to check whether any protected species are present before construction works are carried out. Already, Defra in the UK have approved the use of eDNA sampling to assess the presence of protected great crested newts in ponds.

Now, in a new partnership between Imperial College London and environmental ecology consultancy Thomson Ecology, scientists are hoping to expand the use of eDNA. They want to create protocols to assess whether different areas are home to key protected species, including crayfish, water voles, otters and reptiles.

As well as looking at key protected species for conservation, the team want to use eDNA for biosecurity, by identifying invasive species. For example, as well as native crayfish, some UK waters have been occupied by invasive American Signal Crayfish, which outcompete the native species and damage the local environment. Early detection of invasive crayfish could mean they are dealt with sooner, and cause less damage.

Ultimately, the researchers hope to be able to use eDNA to profile entire ecosystems, analysing water samples to get a snapshot of all the organisms present in the local environment that have shed some DNA.

Victoria Priestley, who is taking on this task for her PhD thesis in the Department of Life Sciences at Imperial, said: "I think eDNA surveys represent a sea change in how we approach survey and monitoring of species.

"There is a lot of effort going into eDNA research globally and once it becomes more established, we should be able to assess what species are present in an area much more quickly. Ultimately we should be able to use it to create a clearer and more detailed picture of global biodiversity."

Efficient Environmental Assessments

Currently, species are assessed based on intensive field surveys, requiring taxonomic expertise and often involving tagging animals and repeat visits to a site. However, Professor Vincent Savolainen, from the Department of Life Sciences at Imperial, is developing new protocols for various species.

This is paving the way for much simpler and more cost-effective surveying for environmental assessments. Professor Savolainen said: "This research will contribute to developing new indices to meet goals of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the body that assesses the state of biodiversity and of the ecosystem services it provides to society, in response to requests from decision makers."

Although sequencing techniques have improved dramatically in the last few decades, challenges remain in analysing eDNA. The fragments degrade over time, a process enhanced by temperature, microbes, enzymes and salinity.

The rate that eDNA is 'shed' from species to species and individual to individual also requires more research, as does the role of predators in moving eDNA between sites, and especially how eDNA is distributed in aquatic environments.

However, Priestley is positive that eDNA surveys have a bright future: "There is still some way to go before whole-ecosystem eDNA monitoring is standard practice, but I believe that at least in the near future, eDNA will increasingly be one of the options in the survey toolkit, working alongside traditional methods to obtain the best ecological survey data in the most efficient way."

Positive Partnership

Professor Tom Welton, Dean of the Faculty of Natural Sciences, said partnerships like this one help translate research into real-world applications: "This exciting collaboration demonstrates that research across the whole breadth of natural sciences at Imperial, even on newts, has practical applications to real world problems.

"Our partnership with Thomson Ecology will allow our research to have a positive impact on environmental protection and conservation."

Author: Hayley Dunning | Source: Imperial College London [November 25, 2016]

Species across the world are rapidly going extinct due to human activities, but humans are also causing rapid evolution and the emergence of new species. A new study published today summarises the causes of humanmade speciation, and discusses why newly evolved species cannot simply replace extinct wild species. The study was led by the Center for Macroecology, Evolution and Climate at the University of Copenhagen.

A growing number of examples show that humans not only contribute to the extinction of species but also drive evolution, and in some cases the emergence of entirely new species. This can take place through mechanisms such as accidental introductions, domestication of animals and crops, unnatural selection due to hunting, or the emergence of novel ecosystems such as the urban environment.

Although tempting to conclude that human activities thus benefit as well as deplete global biodiversity, the authors stress that extinct wild species cannot simply be replaced with newly evolved ones, and that nature conservation remains just as urgent.

"The prospect of 'artificially' gaining novel species through human activities is unlikely to elicit the feeling that it can offset losses of 'natural' species. Indeed, many people might find the prospect of an artificially biodiverse world just as daunting as an artificially impoverished one" says lead author and Postdoc Joseph Bull from the Center for Macroecology, Evolution and Climate at the University of Copenhagen.

The study which was carried out in collaboration with the University of Queensland was published in >Proceedings of Royal Society B. It highlights numerous examples of how human activities influence species' evolution. For instance: as the common house mosquito adapted to the environment of the underground railway system in London, it established a subterranean population. Now named the 'London Underground mosquito', it can no longer interbreed with its above ground counterpart and is effectively thought to be a new species.

"We also see examples of domestication resulting in new species. According to a recent study, at least six of the world's 40 most important agricultural crops are considered entirely new" explains Joseph Bull.

Furthermore, unnatural selection due to hunting can lead to new traits emerging in animals, which can eventually lead to new species, and deliberate or accidental relocation of species can lead to hybridization with other species. Due to the latter, more new plant species in Europe have appeared than are documented to have gone extinct over the last three centuries.

Although it is not possible to quantify exactly how many speciation events have been caused through human activities, the impact is potentially considerable, the study states.

"In this context, 'number of species' becomes a deeply unsatisfactory measure of conservation trends, because it does not reflect many important aspects of biodiversity. Achieving a neutral net outcome for species numbers cannot be considered acceptable if weighing wild fauna against relatively homogenous domesticated species. However, considering speciation alongside extinction may well prove important in developing a better understanding of our impact upon global biodiversity. We call for a discussion about what we, as a society, actually want to conserve about nature" says Associate Professor Martine Maron from the University of Queensland.

Researchers do agree that current extinction rates may soon lead to a 6th period of mass extinction. Since the last Ice Age, 11.500 years ago, it is estimated that 255 mammals and 523 bird species has gone extinct, often due to human activity. In the same period, humans have relocated almost 900 known species and domesticated more than 470 animals and close to 270 plant species.

Source: Faculty of Science - University of Copenhagen [June 28, 2016]

The first annual State of the World's Plants report, which involved more than 80 scientists and took a year to produce, is a baseline assessment of current knowledge on the diversity of plants on earth, the global threats these plants currently face, as well as the policies in place and their effectiveness in dealing with threats.

"This is the first ever global assessment on the state of the world's plants. We already have a 'State of the World's ...birds, sea-turtles, forests, cities, mothers, fathers, children even antibiotics' but not plants. I find this remarkable given the importance of plants to all of our lives- from food, medicines, clothing, building materials and biofuels, to climate regulation. This report therefore provides the first step in filling this critical knowledge gap." said Professor Kathy Willis, Director of Science at the Royal Botanic Gardens, Kew at the report launch on Monday.

"But to have effect, the findings must serve to galvanise the international scientific, conservation, business and governmental communities to work together to fill the knowledge gaps we've highlighted and expand international collaboration, partnerships and frameworks for plant conservation and use," she added.

The status of plants outlined in the report is based on the most up to date knowledge from around the world as of 2016 and is divided into three sections; describing the world's plants, global threats to plants and policies and international trade.

Naming and Counting

The first section focuses on the diversity of plants on earth, noting that there are now an estimated 391,000 vascular plants known to science of which 369,000 are flowering plants -- with around 2,000 new vascular plant species described annually. Some of the most exciting were found during fieldwork while many others were detected only after they have already been preserved and filed as herbarium specimens and a few have been discovered in the glasshouses at Kew.

One of the largest carnivorous plants known (1.5m in height), a new insect-eating plant of the sundew genus called Drosera magnifica was even first discovered on Facebook. Eighteen new species of the genus Ipomoea in the morning glory family, were described from Bolivia last year, among them a close relative of the sweet potato, Ipomoea batatas, offering exciting options for the future of this crop.

"But there are still large parts of the world where very little is known about plants. Identification of these important plant areas is now critical." said Steve Bachman, strategic output leader for the State of the World´s Plants report, RBG Kew. "Similarly, we still only know a fraction of the genetic diversity of plants and whole-genome sequences are currently available for just 139 species of vascular plants. Activity in this area needs to speed up," he added.

Useful plants

In terms of the uses of plants, the report collates data from multiple data sources to reveal that at least 31,000 plant species have a documented use for medicines, food, materials and so on. The majority (17,810 plants) of those now documented have a medicinal use.

Aside from the plants that are currently in use, the report looks at where collection efforts should focus to include plants that will be useful in the future. One set of plant species of critical importance to global food security are the wild relatives of crops, a pool of genetic variation that can help to drive the improvement of our crops into the future. A recent inventory has revealed that there are currently 3,546 prioritised global plant taxa identified as 'crop wild relatives' and Kew's Millennium Seed Bank (MSB) includes 688 crop wild relatives among its over 78,000 accessions, but there are still substantial gaps.

Research in this sector has found that the traits that have been bred into crops over years of domestication are not necessarily the same ones that will provide the greatest climate resilience. Given that many of the wild populations of these species are under considerable threat due to land-use and climate change there is an urgent need to conserve those species not adequately represented in current collections. More seed banking will help preserve a wider range of alternatives to the crops on which the world over relies today (report pages 20-23).

Climate change

The report also explores current knowledge around the impact of climate change on plants and finds that while there is a good understanding for some regions of the world, there are still large areas for which little or no research exists. In those areas where good data is available, clear impacts are visible, including changes in flowering times, turnover in plant communities and movement of species with changing climates.

Research referenced in the report shows that all but one of the world's biomes have experienced more than 10% change in land-cover type in the past decade due to the combined impacts of land-use and climate change.

This research, led by teams at the International Center for Tropical Agriculture in Colombia is also the first of its kind to allocate timeframes for the changes in policy and practice needed to maintain food production and security in Africa. It identifies that up to 30% of areas growing maize and bananas, and up to 60% of those growing beans, are likely to become unviable by the end of the century. But it also highlights some crops like cassava and yams that are showing much greater resilience and could worth focusing on in years to come (report pages 36-39).

"Having proof that root crops like cassava and yams are among the climate-smart crops of the future for sub Saharan Africa is vital for informing policy and planning today," added Professor Willis.

Further research into building a climate resilient coffee economy in Ethiopia published in this report highlights how coffee production is likely to be drastically affected by climate change, but claims that this could be offset if there were interventions now to develop new areas for coffee plantations, which may even lead to gains in coffee production.

Important plant areas

1,771 important plant areas have been identified globally but very few currently have conservation protection. In the UK alone, 165 such sites have been recognised, including parts of the Atlantic woodlands and the Celtic rainforests which are considered to be globally important. These sites include the Lizard in Cornwall, the Brecklands in East Anglia and parts of the west coast of Scotland. Important plant areas have also been identified in several of the UK Overseas Territories including the Falkland Islands and plans are underway to extend this programme to the Caribbean UK Overseas Territories.

Invasive species

A large movement of invasive alien plant species is also occurring. Nearly 5000 plant species are now documented as invasive in global surveys. These plants are causing large declines in native plants, damaging natural ecosystems, transforming land-cover and often causing huge economic losses. In the UK, this includes the highly invasive Japanese knotweed (Reynoutria japonica), introduced as an ornamental plant to Britain in the mid-19th century and costing Great Britain more than £165 million annually to control (report pages 48-51).

The report calls for closer collaboration between institutions and organisations working with invasive species to enable the establishment of a single global list that documents taxonomy, threat, distribution, control and other relevant information. Stricter enforcement of legislation and increased implementation of quarantine procedures would minimise the risk of further.

Plant diseases

There are many emerging threats also occurring with plant diseases, and research effort into these diseases is skewed towards countries with a wealthier research infrastructure.

Threats and extinction

Best estimates lead us to believe that 21% of the world's plants are currently threatened with extinction and ongoing monitoring will allow us to determine whether the trend is of plants slipping closer towards extinction or becoming less threatened.

Plants and policies

Although trade in plants supports livelihoods worldwide, illegal or unsustainable trade is causing additional pressure on wild biodiversity and strict enforcement of international legislation is crucial. Adoption and implementation of policies such as CITES (Convention on International Trade in Endangered Species) have had demonstrable benefits and there is cause for optimism that the Nagoya Protocol will enhance the effectiveness with which countries conserve and utilise their biodiversity.

One of the main plant groups that are still widely traded are orchids, a fact confirmed by data from the UK borderforce. Of all plants plants seized at Heathrow airport in 2015 over 42% were wild orchids.

"This is the most significant horizon-scanning document to be released by Kew in recent decades and I hope as many people as possible will access the findings," said Richard Deverell, Director of the Royal Botanic Gardens, Kew.

"Plants represent one of the most important constituents of biodiversity, the foundation of most of the world's ecosystems and hold the potential to tackle many of the world's present and future challenges. We are uniquely placed to unlock their importance and are proud to have both the catalogue of over 250 years of collections and active scientific field work globally that allows us to interpret the data so it will have multiple uses for generations to come," he added.

Read the report >here.

Source: Royal Botanic Gardens Kew [May 11, 2016]

A relationship that has lasted for 100 million years is at serious risk of ending, due to the effects of environmental and climate change. A species of spiny crayfish native to Australia and the tiny flatworms that depend on them are both at risk of extinction, according to researchers from the UK and Australia.

Look closely into one of the cool, freshwater streams of eastern Australia and you might find a colourful mountain spiny crayfish, from the genus Euastacus. Look even closer and you could see small tentacled flatworms, called temnocephalans, each only a few millimetres long. Temnocephalans live as specialised symbionts on the surface of the crayfish, where they catch tiny food items, or inside the crayfish's gill chamber where they can remove parasites. This is an ancient partnership, but the temnocephalans are now at risk of coextinction with their endangered hosts. Coextinction is the loss of one species, when another that it depends upon goes extinct.

In a new study, researchers from the UK and Australia reconstructed the evolutionary and ecological history of the mountain spiny crayfish and their temnocephalan symbionts to assess their coextinction risk. This study was based on DNA sequences from crayfish and temnocephalans across eastern Australia, sampled by researchers at James Cook University, sequenced at the Natural History Museum, London and Queensland Museum, and analysed at the University of Sydney and the University of Cambridge. The results are published in the >Proceedings of the Royal Society B.

"We've now got a picture of how these two species have evolved together through time," said Dr Jennifer Hoyal Cuthill from Cambridge's Department of Earth Sciences, the paper's lead author. "The extinction risk to the crayfish has been measured, but this is the first time we've quantified the risk to the temnocephalans as well -- and it looks like this ancient partnership could end with the extinction of both species."

Mountain spiny crayfish species diversified across eastern Australia over at least 80 million years, with 37 living species included in this study. Reconstructing the ages of the temnocephalans using a 'molecular clock' analysis showed that the tiny worms are as ancient as their crayfish hosts and have evolved alongside them since the Cretaceous Period.

>A symbiotic relationship that has existed since the time of the dinosaurs is at risk of ending,> as habitat loss and environmental change mean that a species of Australian crayfish >and the tiny worms that depend on them are both at serious risk of extinction >[Credit: David Blair/James Cook University]
Today, many species of mountain spiny crayfish have small geographic ranges. This is especially true in Queensland, where mountain spiny crayfish are restricted to cool, high-altitude streams in small pockets of rainforest. This habitat was reduced and fragmented by long-term climate warming and drying, as the continent of Australia drifted northwards over the last 165 million years. As a consequence, mountain spiny crayfish are severely threatened by ongoing climate change and the International Union for the Conservation of Nature (IUCN) has assessed 75% of these species as endangered or critically endangered.

"In Australia, freshwater crayfish are large, diverse and active 'managers', recycling all sorts of organic material and working the sediments," said Professor David Blair of James Cook University in Australia, the paper's senior author. "The temnocephalan worms associated only with these crayfish are also diverse, reflecting a long, shared history and offering a unique window on ancient symbioses. We now risk extinction of many of these partnerships, which will lead to degradation of their previous habitats and leave science the poorer."

The crayfish tend to have the smallest ranges in the north of Australia, where the climate is the hottest and all of the northern species are endangered or critically endangered. By studying the phylogenies (evolutionary trees) of the species, the researchers found that northern crayfish also tended to be the most evolutionarily distinctive. This also applies to the temnocephalans of genus Temnosewellia, which are symbionts of spiny mountain crayfish across their geographic range. "This means that the most evolutionarily distinctive lineages are also those most at risk of extinction," said Hoyal Cuthill.

The researchers then used computer simulations to predict the extent of coextinction. This showed that if all the mountain spiny crayfish that are currently endangered were to go extinct, 60% of their temnocephalan symbionts would also be lost to coextinction. The temnocephalan lineages that were predicted to be at the greatest risk of coextinction also tended to be the most evolutionarily distinctive. These lineages represent a long history of symbiosis and coevolution of up to 100 million years. However they are the most likely to suffer coextinction if these species and their habitats are not protected from ongoing environmental and climate change.

"The intimate relationship between hosts and their symbionts and parasites is often unique and long lived, not just during the lifespan of the individual organisms themselves but during the evolutionary history of the species involved in the association," said study co-author Dr Tim Littlewood of the Natural History Museum. "This study exemplifies how understanding and untangling such an intimate relationship across space and time can yield deep insights into past climates and environments, as well as highlighting current threats to biodiversity."

Source: University of Cambridge [May 24, 2016]

The appearance of infectious diseases in new places and new hosts, such as West Nile virus and Ebola, is a predictable result of climate change, says a noted zoologist affiliated with the Harold W. Manter Laboratory of Parasitology at the University of Nebraska-Lincoln.

In an article published online today in conjunction with a special issue of the Philosophical Transactions of the Royal Society B, Daniel Brooks warns that humans can expect more such illnesses to emerge in the future, as climate change shifts habitats and brings wildlife, crops, livestock, and humans into contact with pathogens to which they are susceptible but to which they have never been exposed before.

"It's not that there's going to be one 'Andromeda Strain' that will wipe everybody out on the planet," Brooks said, referring to the 1971 science fiction film about a deadly pathogen. "There are going to be a lot of localized outbreaks putting pressure on medical and veterinary health systems. It will be the death of a thousand cuts."

Brooks and his co-author, Eric Hoberg, a zoologist with the U.S. National Parasite Collection of the USDA's Agricultural Research Service, have personally observed how climate change has affected very different ecosystems. During his career, Brooks has focused primarily on parasites in the tropics, while Hoberg has worked primarily in Arctic regions.

Each has observed the arrival of species that hadn't previously lived in that area and the departure of others, Brooks said.

"Over the last 30 years, the places we've been working have been heavily impacted by climate change," Brooks said in an interview last week. "Even though I was in the tropics and he was in the Arctic, we could see something was happening." Changes in habitat mean animals are exposed to new parasites and pathogens.

For example, Brooks said, after humans hunted capuchin and spider monkeys out of existence in some regions of Costa Rica, their parasites immediately switched to howler monkeys, where they persist today. Some lungworms in recent years have moved northward and shifted hosts from caribou to muskoxen in the Canadian Arctic.

But for more than 100 years, scientists have assumed parasites don't quickly jump from one species to another because of the way parasites and hosts co-evolve.

Brooks calls it the "parasite paradox." Over time, hosts and pathogens become more tightly adapted to one another. According to previous theories, this should make emerging diseases rare, because they have to wait for the right random mutation to occur.

However, such jumps happen more quickly than anticipated. Even pathogens that are highly adapted to one host are able to shift to new ones under the right circumstances.

Brooks and Hoberg call for a "fundamental conceptual shift" recognizing that pathogens retain ancestral genetic capabilities allowing them to acquire new hosts quickly.

"Even though a parasite might have a very specialized relationship with one particular host in one particular place, there are other hosts that may be as susceptible," Brooks said.

In fact, the new hosts are more susceptible to infection and get sicker from it, Brooks said, because they haven't yet developed resistance.

Though resistance can evolve fairly rapidly, this only changes the emergent pathogen from an acute to a chronic disease problem, Brooks adds.

"West Nile Virus is a good example - no longer an acute problem for humans or wildlife in North America, it nonetheless is hhere to stay," he said.

The answer, Brooks said, is for greater collaboration between the public and veterinary health communities and the "museum" community - the biologists who study and classify life forms and how they evolve.

In addition to treating human cases of an emerging disease and developing a vaccine for it, he said, scientists need to learn which non-human species carry the pathogen.

Knowing the geographic distribution and the behavior of the non-human reservoirs of the pathogen could lead to public health strategies based on reducing risk of infection by minimizing human contact with infected animals, much likethose that reduced the incidence of malaria and yellow fever by reducing human contact with mosquitos.

Museum scientists versed in understanding the evolutionary relationships among species could use this knowledge to anticipate the risk of the pathogen becoming established outside of its native range.

Brooks, who earned his bachelor's and master's degrees from the University of Nebraska-Lincoln, was a zoology professor at the University of Toronto for 30 years until he retired early in 2011 to devote more time to his study of emerging infectious disease. In addition to being a senior research fellow with UNL's Manter Laboratory, he is a visiting senior fellow at the Universidade Federal do Parana, Brazil, funded by the Ciencias sem Fronteiras (Sciences without Borders) of the Brazilian government, and a visiting scholar with Debrecen University in Hungary.

Brooks' and Hoberg's article, "Evolution in action: climate change, biodiversity dynamics and emerging infectious disease," is part of a Philosophical Transactions of the Royal Society B issue on "Climate change and vector-borne diseases of humans," edited by Paul Parham, a specialist in infectious disease epidemiology at Imperial College in London.

"We have to admit we're not winning the war against emerging diseases," Brooks said. "We're not anticipating them. We're not paying attention to their basic biology, where they might come from and the potential for new pathogens to be introduced."

Source: University of Nebraska-Lincoln [February 16, 2015]

Even if people completely stopped converting tropical forests into farmland, the impacts of tropical deforestation would continue to be felt for many years to come. That's the conclusion of researchers reporting in the Cell Press journal >Current Biology who have used historical rates and patterns of tropical deforestation around the globe to estimate the resulting carbon emissions and species losses over time.

The findings highlight the importance of accounting for the time lag between deforestation and its environmental impacts in meeting conservation goals.

"We show that even if deforestation had completely halted in 2010, time lags ensured there would still be a carbon emissions debt equivalent to five to ten years of global deforestation and an extinction debt of more than 140 bird, mammal, and amphibian forest-specific species, which, if paid, would increase the number of 20th century extinctions in these groups by 120 percent," says Isabel Rosa (@isamdr86) of the Imperial College of London. "Given the magnitude of these debts, commitments to reduce emissions and biodiversity loss are unlikely to be realized without specific actions that directly address this damaging environmental legacy."

It takes time after trees are cut down before the wood and other plant matter left at the site fully decay, releasing carbon into the atmosphere. The resulting loss of habitat also leads to species losses, but those effects also tend to occur gradually.

In the new study, Rosa and her colleagues used a spatially explicit land cover change model to reconstruct the annual rates and spatial patterns of tropical deforestation from 1950 to 2009 in the Amazon, Congo Basin, and Southeast Asia. Using those patterns, they estimated the resulting gross vegetation carbon emissions and species losses.

The findings show that current emissions and species extinctions are mostly tied to past actions. As a result, the researchers explain, changes in annual deforestation rates will initially have a smaller than expected effect on annual carbon emissions. For example, they write, a 30 percent reduction in deforestation rates as seen in the Brazilian Amazon between 2005 and 2010 only cut carbon emissions over the same time period by 10 percent.

The researchers also show that modern deforestation has left us with an estimated extinction debt of 144 vertebrate species found only in tropical forests. That's 20 percent more than the number of extinctions known to have occurred in vertebrate groups in more than a century.

"I expected an increase in both carbon emissions and species extinctions debts, but the magnitude of these debts was surprising," Rosa says.

The findings show that reaching national and global emissions targets will be even more challenging than anticipated.

"We need to do more if we want to avoid paying these debts, thus preventing further loss of species and carbon emissions," Rosa said. "We need to preserve existing habitats, but also restore forests that have been degraded. Allowing the forest to regrow on areas that have been deforested helps by creating 'new' suitable areas for species to survive in while allowing some of this excess carbon to be stored back in the new trees rather than emitted into the atmosphere."

Rosa says she'll continue to pursue the use of their models to support better policy and management decisions.

Source: Cell Press [July 28, 2016]

Marine turtles experienced an evolutionary windfall thanks to a mass extinction of crocodyliforms around 145 million years ago, say researchers.

Crocodyliforms comprise modern crocodiles and alligators and their ancient ancestors, which were major predators that thrived on Earth millions of years ago. They evolved into a variety of species including smaller ones that lived on land through to mega-sized sea-swimming species that were up to 12 metres long. However, around 145 million years ago crocodyliforms, along with many other species, experienced a severe decline - an extinction event during a period between two epochs known as the Jurassic/Cretaceous boundary.

Now a PhD student and his colleagues from Imperial College London and University College London have carried out an extensive analysis of 200 species of crocodyliforms from a fossil database. One of the findings of the study is that the timing of the extinction coincided with the origin of modern marine turtles. The team suggest that the ecological pressure may have been lifted from early marine turtle ancestors due to the extinction of many marine crocodyliforms, which were one of their primary predators.

Jon Tennant, lead author of the study from the Department of Earth Science and Engineering at Imperial, said: "This major extinction of crocodyliforms was literally a case of out with the old and in with the new for many species. Marine turtles, the gentle, graceful creatures of the sea, may have been one of the major winners from this changing of the old guard. They began to thrive in oceans around the world when their ferocious arch-predators went into terminal decline."

In the study, published in the journal Proceedings of the Royal Society B, the researchers point to evidence in the records of a dramatic extinction of crocodyliforms during the Jurassic/Cretaceous boundary. Up to 80 per cent of species on land and in marine environments were wiped out. This decline was primarily due to a drop in sea levels, which led to a closing off of shallow marine environments such as lagoons and coastal swamps. These were the homes and primary hunting grounds for many crocodyliforms.

The decimation of many marine crocodyliforms may also have laid the way for their ecological replacement by other large predatory groups such as modern shark species and new types of plesiosaurs. Plesiosaurs were long-necked, fat-bodied and small-headed ocean-going creatures with fins, which later went extinct around 66 million years ago.

Other factors that contributed to the decline of marine crocodyliforms included a change in the chemistry of ocean water with increased sulphur toxicity and a depletion of oxygen.

While primitive crocodyliform species on land also suffered major declines, the remaining species diversified into new groups such as the now extinct notosuchians, which were much smaller in size at around 1.5 metres in length. Eusuchians also came to prominence after the extinction, which led to today's crocodiles.

To carry out the study on crocodyliforms the team used the Paleobiology Database, which is a professionally curated digital archive of all known fossil records. The team analysed almost 1,200 crocodyliform fossil records.

Scientists have known since the early 1970s about the Jurassic/Cretaceous boundary extinction from fossil records. However, researchers have focussed on other extinction events and as a consequence less has been done to understand in detail the effects of Jurassic/Cretaceous boundary extinction on species like crocodyliforms.

The next steps will see the analysis extended to other groups including dinosaurs, amphibians and mammals to learn more about the effects of the Jurassic/Cretaceous boundary on their biodiversity

Source: Imperial College London [March 09, 2016]

Scientists have developed the largest ever family tree of a major group of flowering plants called monocots, which could help protect their diversity.

Monocots account for a quarter of all flowering plants. They are among the most diverse and economically important plants on the planet, but their evolutionary lines have never been properly mapped. Monocots include staples such as corn, rice, wheat and barley; many tropical fruits such as pineapples and bananas; and other foods such as dates and sugarcane. Monocots such as grasses, bamboo, palms, and their derivations including fibres, are used as key building materials in many countries such as in China.

Now, researchers at Imperial College London have created the most up-to-date family tree or phylogenetic tree, which traces the lines of evolutionary descent of monocots. The researchers analysed DNA samples from across the globe, aiming to determine what factors affected the diversity of monocot species.

Their work could help scientists to conserve the biodiversity of monocots and lead to new types of uses for these plants, such as in the development of new medicines.

Professor Vincent Savolainen, study co-author from the Department of Life Sciences at Imperial College London, said: "Monocots are so important in our lives, providing us with essential food and building materials. Our study is not only the most detailed family tree of monocot species ever developed, it is also importantly helping us to understand what factors affect their diversity. This could lead to better methods for conserving and protecting them.

"It may also lead to new uses for them such as in medicines. Sometimes the best active compound to use in medicine is found in a different species to the one in which it was initially discovered. Therefore, testing close evolutionary relatives may reveal a slightly different molecule that has a stronger effect in combatting one particular disease."

As expected, the team in today's study found that biological factors - such as the way different monocots evolved to take advantage of their environment - played a part in their diversity. However, the researchers discovered that the most important factors in the diversity of monocots in any given region were geographical factors such as the habitat size, its latitude, and altitude.

In particular, they found that the size of the habitat accounted for a third of the species diversity. They suggest this is likely because a bigger habitat means that there are generally more resources and less competition, which enables more species to thrive together rather than compete against each other. They also found that species diversity was reduced at higher altitudes. This may be because temperatures are lower and there is less water available, which causes fiercer competition among monocots for fewer resources.

The researchers were also able to verify previous findings that monocot species are most varied around the equator, and that the closer monocots are to the poles, the fewer species are available. This might be due to higher UV radiation at the equator, causing more genetic mutations and species variation in equatorial regions as a result.

This research analyses 1,987 of the 2,713 types of monocot worldwide. Researchers in this field will now look to increase their sampling to ultimately encompass the roughly 400,000 plant species, to create the entire botanical 'tree of life'.

The study was published in >Botanical Journal of the Linnean Society.

Author: Caroline Brogan | Source: Imperial College London [November 09, 2016]

Researchers from CSIRO and Imperial College London have assessed how widespread the threat of plastic is for the world's seabirds, including albatrosses, shearwaters and penguins, and found the majority of seabird species have plastic in their gut.

The study, led by Dr Chris Wilcox with co-authors Dr Denise Hardesty and Dr Erik van Sebille and published today in the journal PNAS, found that nearly 60 per cent of all seabird species have plastic in their gut.

Based on analysis of published studies since the early 1960s, the researchers found that plastic is increasingly common in seabird's stomachs.

In 1960, plastic was found in the stomach of less than 5 per cent of individual seabirds, rising to 80 per cent by 2010.

The researchers predict that plastic ingestion will affect 99 per cent of the world's seabird species by 2050, based on current trends.

The scientists estimate that 90 per cent of all seabirds alive today have eaten plastic of some kind.

This includes bags, bottle caps, and plastic fibres from synthetic clothes, which have washed out into the ocean from urban rivers, sewers and waste deposits.

Birds mistake the brightly coloured items for food, or swallow them by accident, and this causes gut impaction, weight loss and sometimes even death.

"For the first time, we have a global prediction of how wide-reaching plastic impacts may be on marine species -- and the results are striking," senior research scientist at CSIRO Oceans and Atmosphere Dr Wilcox said.

"We predict, using historical observations, that 90 per cent of individual seabirds have eaten plastic. This is a huge amount and really points to the ubiquity of plastic pollution."

Dr Denise Hardesty from CSIRO Oceans and Atmosphere said seabirds were excellent indicators of ecosystem health.

"Finding such widespread estimates of plastic in seabirds is borne out by some of the fieldwork we've carried out where I've found nearly 200 pieces of plastic in a single seabird," Dr Hardesty said.

The researchers found plastics will have the greatest impact on wildlife where they gather in the Southern Ocean, in a band around the southern edges of Australia, South Africa and South America.

Dr van Sebille, from the Grantham Institute at Imperial College London, said the plastics had the most devastating impact in the areas where there was the greatest diversity of species.

"We are very concerned about species such as penguins and giant albatrosses, which live in these areas," Erik van Sebille said.

"While the infamous garbage patches in the middle of the oceans have strikingly high densities of plastic, very few animals live here."

Dr Hardesty said there was still the opportunity to change the impact plastic had on seabirds.

"Improving waste management can reduce the threat plastic is posing to marine wildlife," she said.

"Even simple measures can make a difference. Efforts to reduce plastics losses into the environment in Europe resulted in measureable changes in plastic in seabird stomachs with less than a decade, which suggests that improvements in basic waste management can reduce plastic in the environment in a really short time."

Chief Scientist at the US-based Ocean Conservancy Dr George H. Leonard said the study was highly important and demonstrated how pervasive plastics were in oceans.

"Hundreds of thousands of volunteers around the world come face-to-face with this problem during annual Coastal Cleanup events," Dr Leonard said.

"Scientists, the private sector and global citizens working together against the growing onslaught of plastic pollution can reduce plastic inputs to help protect marine biodiversity."

Source: CSIRO Australia [September 01, 2015]

Scientists from Wageningen UR and other institutes are proposing a new research model - the turnover model - as a way of answering the question why there are always so many plant species in tropical rainforests.

In their publication in New Phytologist magazine, the Dutch, British and Swiss scientists show that major evolutionary changes, such as the origin of large groups of species, occur with a reasonably constant frequency while the origin of new species is an explosive process.

Various models

Darwin’s contemporary Alfred Russel Wallace already argued that the Tropics are, in essence, a museum of biodiversity. As tropical climates are stable, Wallace suggested that species would gradually increase in number over longer time periods, the so-called museum model. More recently, however, it was suggested that the Pleistocene ice ages, and the impact thereof on the climate in the Tropics, resulted in recent explosions of speciation, the so-called cradle model.

Both models are supported by previous research into patterns of diversification in tropical plants. This research is performed by means of reconstructed ‘phylogenetic trees’; genealogical trees that show the interrelated  descent of plant species. Where analyses of plant families focused on studying as many evolutionary lines as possible from the family, diversity was shown to increase gradually. For instance, the development of diversity in important tropical plant groups such as palm trees, the leguminous family and the soursop family, appear to follow the museum model. However, within these large plant families there are also plant genera that seem to follow the cradle model: so-called radiations in which many different species developed recently and over a short period of time.

Equatiing seems impossible

Equating these two models seems an impossible task. How can a large plant family that presents an explosive increase in the number of species diversify as an entire family following the museum model? The answer lies in analysing more species per family, and better modelling speciation over long periods in evolution via the computer.

Mahogany trees

Scientists from Wageningen UR, Kew (London) and Zürich compiled the largest amount of data so far for the Meliaceae , or mahogany family. This family mainly grows in the Tropics, and is known for valuable wood such as mahogany and Spanish cedar. Parts of the nuclear and chloroplast genome of approximately 35% of the species were sequenced; a technology in which all the building blocks of the DNA are mapped.

The analysis of evolutionary diversification showed that the diversity of larger groups, such as plant genera and families, does develop in accordance with the museum model, i.e., with a certain constant frequency in the origin of new branches. The scientists showed that, in addition to this ‘museum fundament’, the origin of individual species is an explosive process which occurs in accordance with the cradle model.

‘Young’ species

The research shows that the mahogany family developed approximately 68 million years ago. The circa 200 mahogany species that grow in the South American rainforests are largely the result of two explosions in speciation (radiations) that occurred independently in two evolutionary lines in the late Miocene epoch, which was less than 10 million years ago.

An interesting aspect of this explosive origin of large numbers of species within the mahogany family is that it involves two different groups within the family which independently evolved the same ecological adaptations, such as plant height and an adaptation of seeds to the same animal species that distribute them. In addition, the two groups show a similar speed of speciation. These abrupt increases in speciation speed occurred after the mahogany family had left its original habitat (tropical dry forests and seasonal forests) and colonised the rainforests, where they were faced with different climate conditions.

New model for evolution

The results of the study show that most mahogany species in the Tropics are relatively recent. It can be assumed that this also applies to other families. The authors propose a new model, the turnover model, in which the number of evolutionary lines increases with a more or less constant speed, while speciation occurs separately and in a more explosive way.

Source: Wageningen University [June 19, 2015]

Large ornamental structures in dinosaurs, such as horns and head crests are likely to have been used in sexual displays and to assert social dominance, according to a new analysis of Protoceratops carried out by scientists at Queen Mary University of London (QMUL). This is the first time scientists have linked the function of anatomy to sexual selection in dinosaurs.

Protoceratops had a large bony frill that extended from the back of the head over the neck. Study of fossils aged from babies to adults revealed the adults to have disproportionately larger frills in relation to their size. The research, published in the journal >Palaeontologia Electronica, shows that the frill was absent in juveniles and suddenly increased in size as the animals reached maturity suggesting that its function is linked to sexual selection.

This suggests the frill might have been used to attract suitable mates by showing off their best attributes or helping them assert the most dominant position in social interactions.

Dr David Hone, lecturer in Zoology from QMUL's School of Biological and Chemical Sciences, said: "Palaeontologists have long suspected that many of the strange features we see in dinosaurs were linked to sexual display and social dominance but this is very hard to show. The growth pattern we see in Protoceratops matches that seen for signalling structures in numerous different living species and forms a coherent pattern from very young animals right through to large adults."

The researchers assessed the change in length and width of the frill over four life stages: hatchling babies, young animals, near-adults, and adults. Not only did the frill change in size but it also changed in shape, becoming proportionally wider as the dinosaur became older.

Dr Rob Knell, Reader in Evolutionary Ecology, also from QMUL's School of Biological and Chemical Sciences, said: "Biologists are increasingly realising that sexual selection is a massively important force in shaping biodiversity both now and in the past. Not only does sexual selection account for most of the stranger, prettier and more impressive features that we see in the animal kingdom, it also seems to play a part in determining how new species arise, and there is increasing evidence that it also has effects on extinction rates and on the ways by which animals are able to adapt to changing environments."

The research formed part of current postgraduate student and QMUL graduate Dylan Wood's undergraduate thesis, which looked at sexual selection in extinct species.

There are numerous, well-preserved specimens of ceratopisian dinosaurs of various sizes and ages making them a good groups to analyse. The researchers analysed 37 specimens of Protoceratops from fossils found in the Djadochta Formation in the Gobi desert and from previous published research. Protoceratops was a small-horned dinosaur that was similar in size to a sheep and was around 2m in total length from snout to tail tip.

Source: Queen Mary, University of London [January 13, 2016]