It’s estimated that a person sheds between 30,000 to 40,000 skin cells per day. These cells and their associated DNA leave genetic traces of ourselves in showers, dust — pretty much everywhere we go.
Other organisms shed cells, too, leaving traces throughout their habitats. This leftover genetic material is known as environmental DNA, or eDNA. Research using eDNA began about a decade ago, but was largely limited to a small cadre of biologists who were also experts in computers and big data. However, a new tool from UCLA could be about to make the field accessible and useful to many more scientists.
A team of UCLA researchers recently launched the Anacapa Toolkit — open-source software that makes eDNA research easier, allowing researchers to detect a broad range of species quickly and producing sortable results that are simple to understand. Continue reading →
The challenges of collecting DNA samples directly from endangered species makes understanding and protecting them harder. A new approach promises cheap, rapid analysis of genetic clues in degraded and left-behind material, such as hair and commercial food products.
The key to solving a mystery is finding the right clues. Wildlife detectives aiming to protect endangered species have long been hobbled by the near impossibility of collecting DNA samples from rare and elusive animals. Continue reading →
For the first time ZSL scientists were able to use the calls of a species as a proxy for their movement. A happy hihi call sounds like two marbles clanging together in what is known as the ‘stitch’ call. Scientists saw the calls change from an initial random distribution to a more settled home range – marking the hihi reintroduction and the new method a success. Continue reading →
The ANDe system can help researchers tell whether endangered species are present.
In recent years, there have been a lot of studies on the use of environmental DNA (eDNA) for species detection and monitoring. This method takes advantage of the fact that organisms shed DNA into the environment in the form of urine, feces, or cells from tissue such as skin. As this DNA stays in the environment, we can use molecular techniques to search for traces of it. By doing this, we can determine if a species lives in a particular place.
In an age of rapid technological advances, ecologists need to keep abreast of how we can improve or reinvent the way we do things. Remote sensing technology and image analysis have been developing rapidly and have the potential to revolutionise how we count and estimate animal populations.
Using remotely sensed imagery isn’t new in ecology, but recent innovations mean we can use it for more things. Land use change and vegetation mapping are among the areas of ecology where remote sensing has been used extensively for some time. Estimating animal populations with remotely sensed imagery was also demonstrated more than 40 years ago by detecting indirect signs of an animal with some success: think wombat burrows and penguin poop.
A polar bear from a helicopter
Thanks to improved spatial and spectral resolution (see the text box at the bottom of the post for a definition), accessibility, cost and coverage of remotely sensed data, and software development we have now reached a point where we can detect and count individual animals in imagery. Many of the first studies to demonstrate automated and semi-automated techniques have taken computer algorithms from other disciplines, such as engineering or biomedical sciences, and applied them to automate counting of animals in remotely sensed imagery. It turns out that detecting submarines is not so different to detecting whales! And finding abnormal cells in medical imaging is surprisingly similar to locating polar bears in the arctic! Continue reading →
One of the main causes behind biodiversity loss is the reduction and fragmentation of natural habitats. The conversion of natural areas into agricultural, urban or other human-modified landscapes often leaves wild species confined to small and isolated areas of habitat, which can only support small local populations. The problem with small, isolated populations is that they are highly vulnerable to extinction caused by chance events (such as an epidemic or a natural disaster in the area), or by genetic erosion (dramatic loss of genetic diversity that weakens species and takes away their ability to adapt to new conditions).
On top of that, we now have the added concern of climate change, which is altering environmental conditions and shifting habitats to different latitudes and altitudes. To survive in the face of these changes, many species need to modify their geographical distribution and reach new areas with suitable conditions. The combination of mobility (a biological property of species) and the possibility of spatial movement (a physical property of the landscape) is critically important for this. Continue reading →
Rather than conduct an aquatic roll call with nets to know which fish reside in a particular body of water, scientists can now use DNA fragments suspended in water to catalog invasive or native species.
“We’ve sharpened the environmental DNA (eDNA) tool, so that if a river or a lake has threatened, endangered or invasive species, we can ascertain genetic detail of the species there,” said senior author David Lodge, the Francis J. DiSalvo Director of the Atkinson Center for a Sustainable Future at Cornell, and professor of ecology and evolutionary biology. “Using eDNA, scientists can better design management options for eradicating invasive species, or saving and restoring endangered species.” Continue reading →
Our 5th Anniversary Special Feature is a collection of six articles (plus an Editorial from Executive Editor Rob Freckleton) that highlights the breadth and depth of topics covered by the journal so far. It grew out of our 5th Anniversary Symposium – a joint event held in London, UK and Calgary, Canada and live-streamed around the world in April 2015 – and contains papers by Associate Editors, a former Robert May prize winner and regular contributors to the journal.
The six articles are based on talks given at last May’s Symposium. They focus on:
In his Editorial for the Special Feature, Rob Freckleton looks to the future. In his words: “we hope to continue to publish a wide range of papers on as diverse a range of topics as possible, exemplified by the diversity of the papers in this feature”.
In order to help prioritizing conservation efforts, the International Union for Conservation of Nature (IUCN) has published criteria to categorize the status of threatened species, which are then published in Red Lists. Changes in a species’ geographical distribution is one of the several criteria used to assign a threat status. For rare species, however, the exact distribution is often inadequately known. In conservation science, Species Distribution Models (SDMs) have recurrently been used to estimate the potential distribution of rare or insufficiently sampled species. Continue reading →
Friday was Endangered Species Day – so this is a good time to reflect on what science and scientists can do to support conservation efforts and to reduce the rate of species extinctions. One obvious answer is that we need to study endangered species to understand their habitat requirements as well as their potential for acclimatization and adaptation to changing environmental conditions. This information is crucial to for the design of informed conservation planning. However, for most endangered species the relevant phenotypes are not known a priori, which leaves the well-intentioned scientist asking “which traits should I measure?”. Transcriptome analysis is often a good way to answer to this question.