The Power of Infinity: Using 3D Fractal Geometry to Study Irregular Organisms

Post provided by Jessica Reichert, André R. Backes, Patrick Schubert and Thomas Wilke

The Problem with the Shape

More than anything else, the phenotype of an organism determines how it interacts with the environment. It’s subject to natural selection, and may help to unravel the underlying evolutionary processes. So shape traits are key elements in many ecological and biological studies.

The growth form of corals is highly variable. ©Jessica Reichert

The growth form of corals is highly variable. ©Jessica Reichert

Commonly, basic parameters like distances, areas, angles, or derived ratios are used to describe and compare the shapes of organisms. These parameters usually work well in organisms with a regular body plan. The shape of irregular organisms – such as many plants, fungi, sponges or corals – is mainly determined by environmental factors and often lacks the distinct landmarks needed for traditional morphometric methods. The application of these methods is problematic and shapes are more often categorised than actually measured.

As scientists though, we favour independent statistical analyses, and there’s an urgent need for reliable shape characterisation based on numerical approaches. So, scientists often determine complexity parameters such as surface/volume ratios, rugosity, or the level of branching. However, these parameters all share the same drawback: they are delineated to a univariate number, taking information from one or few spatial scales and because of this essential information is lost. Continue reading


More New Associate Editors

Today we are welcoming another two Associate Editors to the Methods in Ecology and Evolution. Just like the seven AEs who joined last week, Michael Matschiner (of the University of Basel, Switzerland) and Tiago Bosisio Quental (of the University of São Paulo, Brazil) were both invited to work with the journal following our open call earlier this year. You can find out more about both of them below.

Michael Matschiner

“I am an evolutionary biologist interested in the processes that drive speciation and generate biodiversity. To learn about these processes, I use phylogenetic divergence-time estimation based on genome sequences and the fossil record. Since both of these data sources do not usually conform to expectations in standard phylogenetic workflows (no recombination, no hybridization, no sampling bias), much of my work involves method development to assess the impact of model violations, and to account for them in phylogenetic reconstruction.”

Tiago Bosisio Quental

“I am interested on understanding spatial and temporal patterns of biodiversity and the mechanisms involved in generating species diversity. I have a particular interest in mammals, but my research interests are not limited to a specific taxonomic group but are instead motivated by a range of questions and structured around them. At the moment, I am particularly interested in understanding the role of biotic interactions on biodiversity changes in deep time. The main tools used to approach those questions are molecular phylogenies, fossil record, ecological data and numerical simulation.”

We are thrilled to welcome Michael and Tiago to the Associate Editor Board and we look forward to working with them over the coming years.

Issue 8.8

Issue 8.10 is now online!

The October issue of Methods is now online!

This double-sized issue contains three Applications articles and two Open Access articles. These five papers are freely available to everyone, no subscription required.

 Phylogenetic TreesThe fields of phylogenetic tree and network inference have advanced independently, with only a few attempts to bridge them. Schliep et al. provide a framework, implemented in R, to transfer information between trees and networks.

 Emon: Studies, surveys and monitoring are often costly, so small investments in preliminary data collection and systematic planning of these activities can help to make best use of resources. To meet recognised needs for accessible tools to plan some aspects of studies, surveys and monitoring, Barry et al. developed the R package emon, which includes routines for study design through power analysis and feature detection.

 Haplostrips: A tool to visualise polymorphisms of a given region of the genome in the form of independently clustered and sorted haplotypes. Haplostrips is a command-line tool written in Python and R, that uses variant call format files as input and generates a heatmap view.

Continue reading

Protecting Habitat Connectivity for Endangered Vultures: Identifying Priorities with Network Analysis

Post provided by Juliana Pereira, Santiago Saura and Ferenc Jordán

The endangered Egyptian vulture. ©Carlos Delgado

The endangered Egyptian vulture. ©Carlos Delgado

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

Valuing Nature the Interdisciplinary Way

Post provided by Graziella Iossa

Before I started my NERC Valuing Nature Placement in April 2017, I’d never done interdisciplinary work. I had been thinking about it for a while though, when I read on Twitter that the Valuing Nature Programme were launching their placement scheme for 2017. I had already been in touch with my prospective hosts – Hilary Graham, Department of Health Science, and Piran White, Environment Department, both at the University of York – but the launch of the scheme galvanised our interest. We put together our application and were delighted to receive funding. So, what is that we set out to do?

Valuing Nature

Piran, Hilary and I had already been talking about projects focusing on knowledge transfer, particularly around collaborative work to tackle antimicrobial resistance. Valuing Nature was the perfect fit for what we wanted to do. The programme aims to further our understanding of nature in valuation analyses and decision making by building an interdisciplinary research community capable of working across the natural, biological and social sciences, as well as the arts and humanities. Interdisciplinarity is integral to the programme. Continue reading

Issue 8.7

Issue 8.7 is now online!

© Paula Matos

The July issue of Methods is now online!

This issue contains three Applications articles (one of which is Open Access) and one additional Open Access article. These four papers are freely available to everyone, no subscription required.

BioEnergeticFoodWebs: An implementation of Yodzis & Innes bio-energetic model, in the high-performance computing language Julia. This package can be used to conduct numerical experiments in a reproducible and standard way.

 Controlled plant crosses: Chambers which allow you to control pollen movement and paternity of offspring using unpollinated isolated plants and microsatellite markers for parents and their putative offspring. This system has per plant costs and efficacy superior to pollen bags used in past studies of wind-pollinated plants.

 The Global Pollen Project: The study of fossil and modern pollen assemblages provides essential information about vegetation dynamics in space and time. In this Open Access Applications article, Martin and Harvey present a new online tool – the Global Pollen Project – which aims to enable people to share and identify pollen grains. Through this, it will create an open, free and accessible reference library for pollen identification. The database currently holds information for over 1500 species, from Europe, the Americas and Asia. As the collection grows, we envision easier pollen identification, and greater use of the database for novel research on pollen morphology and other characteristics, especially when linked to other palaeoecological databases, such as Neotoma.

Continue reading

Bottom-up Citizen Science and Biodiversity Statistics

Post provided by Ditch Townsend and Robert Colwell

Different Paths to Science

Ditch Townsend on Exmoor in Devon, UK

Ditch Townsend on Exmoor in Devon, UK

DITCH: Amateur naturalists from the UK have a distinguished pedigree, from Henry Walter Bates and Marianne North, to Alfred Russel Wallace and Mary Anning. But arguably, the rise of post-war academia in the fifties displaced them from mainstream scientific discourse and discovery. Recently, there has been a resurgence of the ‘citizen scientist’, like me, in the UK and elsewhere – although the term may refer to more than one kind of beast.

To me, the ‘citizen scientist’ label feels a little patronising – conveying an image of people co-opted en masse for top-down, scientist-led, large-scale biological surveys. That said, scientist-led surveys can offer valid contributions to conservation and the documentation of the effects of climate change (among other objectives). They also engage the public (not least children) in science, although volunteers usually have an interest in natural history and science already. For me though, the real excitement comes in following a bottom-up path: making my own discoveries and approaching scientists for assistance with my projects.

Robert Colwell at the Boreas Pass in Colorado, USA

Robert Colwell at the Boreas Pass in Colorado, USA

ROB: I grew up on a working ranch in the Colorado mountains, surrounded on three sides by National Forest and a National Wilderness Area. My mother, an ardent amateur naturalist, taught me and my sister the local native flora and fauna and our father instilled a respect for the land in us. For my doctoral research at the University of Michigan, I studied insect biodiversity in Colorado and Costa Rica at several elevations. The challenges of estimating the number of species (species richness) and understanding why some places are species-rich and others species-poor has fascinated me ever since. Continue reading

The Right Tool for the Job: Using Zeta Diversity to Communicate Uncertainty in Ecological Modelling

Post provided by Mariona Roigé

The Need for Modelling

Green vegetable bug nymph (Nezara viridula). ©John Marris. Lincoln University.

Green vegetable bug nymph (Nezara viridula). ©John Marris. Lincoln University.

Despite how far modelling has taken us in science, the use of models remains controversial. Modelling covers a huge range of common practices, from scaled models of ships to determine the shape that will have the least resistance to water to complex, comprehensive ‘models of everything’. A great example of the latter is the Earth System Model. This model aims to understand the changes in global climate by taking into account the interaction between physical climate, biosphere, the atmosphere and the oceans. Basically, a model of how the Earth works.

The controversy in the use of modelling resides in how accurately the model describes reality and the level of confidence we have in its outputs. The first argument can be a bit counter-intuitive: sometimes, a very simple model can be a great predictor. Actually, the conventional view in ecology is that simple models are more generalisable than complex models, although this view is being challenged. However, the level of confidence, or the level of uncertainty, that we have in the outputs of the model is a crucial point. We need to be able to accurately determine our levels of uncertainty if we want people to trust our models. Continue reading

Fast-Moving Biodiversity Assessment: Are We Already in the Future?

Post provided by Carola Gómez-Rodríguez & Alfried P. Vogler

Time flies… in the blink of an eye! And even more so in science. The molecular lab work we were used to two decades ago seems like ancient history to today’s PhD students. The speed of change in sequencing technology is so overwhelming that imagination usually fails to foresee how our daily work will be in 10 years’ time. But in the field of biodiversity assessment, we have very good clues. Next Generation Sequencing is quickly becoming our workhorse for ambitious projects of species and genetic inventories.

One by One Approach to Studying Biodiversity

For decades, most initiatives measured biodiversity in the same way: collect a sample of many individuals in the field, sort the specimens, identify them to a Linnaean species one at a time (if there was a good taxonomist in the group which, unfortunately, it is kind of lucky these days!), and count them. Or, if identification was based on molecular data, the specimen was subject to DNA extraction, to sequence one (or several) short DNA markers. This involved countless hours of work that could be saved if, instead of inventorying biodiversity specimen-by-specimen, we followed a sample-by-sample approach. To do this now, we just have to make a “biodiversity soup”.

Biodiversity assessment based on morphological identification and/or Sanger sequencing (“The one-by-one approach”)

Biodiversity assessment based on morphological identification and/or Sanger sequencing (“The one-by-one approach”)

Continue reading

Tiny Grains, Big Data: The Global Pollen Project

Post Provided by Andrew Martin

A drawer from the Oxford Long-Term Ecology Lab (OxLEL) pollen reference collections, which has been digitised into the Global Pollen Project reference set.

A drawer from the Oxford Long-Term Ecology Lab (OxLEL) pollen reference collections, which has been digitised into the Global Pollen Project reference set.

The Global Pollen Project is a new, online, freely available tool developed to help people identify and disseminate palynological resources. Palynology – the study of pollen grains and other spores – is used across many fields of study modern and fossil vegetation dynamics, forensic sciences, pollination, beekeeping, and much more. This platform helps to facilitate cross/multi-disciplinary integration and discussion, outsourcing identifications, expertise and the sharing of knowledge.

Pollen’s Role in Plant Conservation

Successful conservation of rare, threatened, and valuable plants is dependent on an understanding of the threats that they face. Also, conservationists must prioritise species and populations based on their value to humans, which may be cultural, economic, medicinal, etc. The study of fossil pollen (palaeoecology), deposited through time in sediments from lakes and bogs, can help inform the debate over which species to prioritise: which are native, and when did they arrive? How did humans impact species richness? By establishing such biodiversity baselines, policymakers can make more informed value judgements over which habitats and species to conserve, especially where conservation efforts are weighted in favour of native and/or endemic flora. Continue reading