Tag Archives: Phylogenetic Diversity

My Entropy ‘Pearl’: Using Turing’s Insight to Find an Optimal Estimator for Shannon Entropy

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Post provided by Anne Chao (National Tsing Hua University, Taiwan)

Shannon Entropy

Not quite as precious as my entropy pearl

Not quite as precious as my entropy pearl ©Amboo Who

Ludwig Boltzmann (1844-1906) introduced the modern formula for entropy in statistical mechanics in 1870s. Since its generalization by Claude E. Shannon in his pioneering 1948 paper A Mathematical Theory of Communication, this entropy became known as ‘Shannon entropy’.

Shannon entropy and its exponential have been extensively used to characterize uncertainty, diversity and information-related quantities in ecology, genetics, information theory, computer science and many other fields. Its mathematical expression is given in the figure below.

In the 1950s Shannon entropy was adopted by ecologists as a diversity measure. It’s interpreted as a measure of the uncertainty in the species identity of an individual randomly selected from a community. A higher degree of uncertainty means greater diversity in the community.

Unlike species richness which gives equal weight to all species, or the Gini-Simpson index that gives more weight to individuals of abundant species, Shannon entropy and its exponential (“the effective number of common species” or diversity of order one) are the only standard frequency-sensitive complexity measures that weigh species in proportion to their population abundances. To put it simply: it treats all individuals equally. This is the most natural weighing for many applications. Continue reading →

Advances in Phylogenetic Methods – The Applications Papers

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Original Image ©PLOS One Phylogeny

Original Image ©PLOS One Phylogeny

Timed to coincide with Evolution 2015, we have released a new Virtual Issue on Phylogenetic Methods. All of the articles in this Virtual Issue will be freely available for a limited period.

On Friday, we gave some more information about the research articles in this Virtual Issue. In this post, we will be focusing on the Applications papers.

Applications papers introduce new tools for research, which provide practitioners with an important source of information and background on the tools they use. In this Virtual Issue we have highlighted the newest Applications papers that describe how phylogenetic methods are contributing to the fields of ecology and evolution. These include tools with aims as diverse as phylogenetic tree reconstruction and analysing phylogenetic diversity in communities. All Applications papers, not just those in the Virtual Issue, are free to access.

You can see a little more information on each of the Applications Papers below.

Continue reading →

Virtual Issue: Advances in Phylogenetic Methods

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Original Image ©PLOS One Phylogeny

Original Image ©PLOS One Phylogeny

Timed to coincide with Evolution 2015, we have released a new Virtual Issue on Phylogenetic Methods. All of the articles in this Virtual Issue will be freely available for a limited period.

An understanding of the tree of life contributes to many facets of biology. This Virtual Issue has assembled studies that showcase the breadth of the utility of phylogenetic trees, including phylogenetic beta diversity, trait evolution, diversification, biodiversity studies, phylogenetic signal, biogeography, ecosystem functioning, and host-pathogen dynamics.

The Research papers included are excellent examples of new ways that phylogenies can be applied to central questions in ecology, evolution and biodiversity, such as measuring niche conservatism, trait evolution and diversification rates. The issue also has articles on barcoding methods, which increasingly are used to understand phylogenetic and functional diversity.

You can see a little more information on each of the articles below.

Continue reading →

International Day for Biological Diversity 2015

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Happy International Day for Biological Diversity everyone!

As you may know, today (Friday 22 May) is the United Nations Day for Biodiversity and we are celebrating by highlighting some of the best papers that have been published on biodiversity in Methods in Ecology and Evolution. This is by no means an exhaustive list and you can find many more articles on similar topics on the Wiley Online Library (remember, if you are a member of the BES, you can access all Methods articles free of charge).

If you would like to learn more about the International Day for Biological Diversity, you may wish to visit the Convention on Biological Diversity website, follow them on Twitter or check out today’s hashtag: #IBD2015.

Without further ado though, here are a few of the best Methods papers on Biological Diversity:

Methods Cover - August 2012Biodiversity Soup

We begin with an Open Access article from one of our Associate Editors, Douglas Yu (et al.). This article was published in the August issue of 2012 and focuses on the metabarcoding of arthropods. The authors present protocols for the extraction of ecological, taxonomic and phylogenetic information from bulk samples of arthropods. They also demonstrate that metabarcoding allows for the precise estimation of pairwise community dissimilarity (beta diversity) and within-community phylogenetic diversity (alpha diversity), despite the inevitable loss of taxonomic information.

Continue reading →

Issue 6.4: Opportunities at the Interface Between Ecology and Statistics

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Issue 6.4 is now online!

© Chun-Huo Chiu and Ching-Wen Cheng

The April issue of Methods, which includes our latest Special Feature: “Opportunities at the Interface Between Ecology and Statistics” is now online!

Opportunities ar the Interface Between Ecology and Statistics is a collection of eight articles which arose from the Eco-Stats Symposium at the University of New South Wales (Australia) in July 2013.This Symposium was designed to be a collaborative forum for researchers with interests in ecology and statistics. It brought together internationally recognised leaders in these two fields (such as Jane Elith, Trevor Hastie, Anne Chao and Shirley Pledger) – many of whom have contributed articles to this Special Feature.

The Eco-Stats Symposium was arranged around five special topics, all of which are represented in this issue of Methods. Those five topics are:

In his Editorial for the Special Feature, Guest Editor David Warton suggests that one of the reasons for the success of Methods in Ecology and Evolution may be that it provides a forum for statisticians and ecologists to interact. The articles in this issue, and the conference that gave rise to them, show that these interactions can provide significant benefits for both groups.

There will be another Eco-Stats Symposium at the University of New South Wales in December of this year (8-10 December, 2015).
For more details on this, please click here. Continue reading →