Ultraconserved Elements are Widely Shared across the Tree of Life

Posted on June 24, 2019 by Chris Grieves

Post provided by SILAS BOSSERT

Large-scale phylogenies are increasingly fueled by genomic-data from Ultraconserved Elements. ©Silas Bossert

Large-scale phylogenies are increasingly fuelled by genomic-data from Ultraconserved Elements. ©Silas Bossert

Sequencing ultraconserved DNA for phylogenetic research is a hot topic in evolution right now. As the name implies, Ultraconserved Elements (UCEs) are regions of the genome that are nearly identical among distantly related organisms. They can provide useful information for difficult phylogenetic questions. The list of advantages is long – among others, UCEs are:

easy to capture and sequence
able to be retained from old and degraded museum material
phylogenetically informative on different timescales.

A key reason for the method’s success is the developers’ commitment to full transparency, active tutoring, and willingness to help next-gen sequencing newbies like me to get started. Help is just a github-issue post away.

It took little to convince me that I wanted to use UCEs to reconstruct the phylogeny of one of my favourite groups of bees. I eventually met that objective but it won’t be part of this post. This blog post is about the journey to get there—the background story to the article ‘On the universality of target‐enrichment baits for phylogenomic research’. Continue reading →

The Dark and Bright Sides of Phylogenetics and Comparative Methods

Posted on June 21, 2019 by Chris Grieves

Five years ago at Evolution 2014, ‘The Dark Side of Phylogenetics’ symposium (organised by Natalie Cooper) explored some of the issues with phylogenetic comparative methods (PCMs). This year at Evolution 2019, Michael Landis and Rosana Zenil-Ferguson are organising a contrasting ‘Bright Side of Phylogenetics‘ spotlight session (featuring Michael Matschiner). They aim to promote research that has overcome these pitfalls and that explores innovations in phylogenetics. Clearly they found our lack of faith disturbing.

Natalie and Michael have created a Virtual Issue to complement the spotlight session: Phylogenetics and Comparative Methods: The Bright and Dark Sides. It highlights recent Methods in Ecology and Evolution papers that feature either the ‘Bright Side’ or ‘Dark Side’ of phylogenetics and comparative methods. This Virtual Issue also highlights the diversity of researchers around the world working on these exciting questions. We hope you have a good feeling about it! Continue reading →

Early Spring: Predicting Budburst with Genetics

Posted on May 17, 2019 by Chris Grieves

Below is a press release about the Methods in Ecology and Evolution article ‘On the importance of accounting for intraspecific genomic relatedness in multi‐species studies‘ taken from the Université de Montréal.

Bud of American beech (Fagus grandifolia). ©Tim Savas

Researchers from Canada and the USA found that tree and shrub genetics can be used to produce more accurate predictions of when leaves will burst bud in the spring. Their study was published in Methods in Ecology and Evolution.

Although climate sceptics might find it hard to believe with this year’s endless snow and freezing temperatures, climate change is making warm, sunny early springs increasingly common. And that affects when trees start to leaf out. But how much?

Simon Joly, biology professor at Université de Montréal and Elizabeth Wolkovich, an ecology professor at University of British Columbia, showed that a plant’s genetics can be used to produce more accurate predictions of when its leaves will burst bud in spring. Continue reading →

2018 Robert May Prize Winner: Laura Russo

Posted on April 29, 2019 by Chris Grieves

The Robert May Prize is awarded annually for the best paper published in Methods in Ecology and Evolution by an Early Career Researcher. We’re delighted to announce that the 2018 winner is Laura Russo, for her article ‘Quantitative evolutionary patterns in bipartite networks: Vicariance, phylogenetic tracking or diffuse co‐evolution?‘.

Plant-pollinator interactions are often considered to be the textbook example of co-evolution. But specialised interactions between plants and pollinators are the exception, not the rule. Plants tend to be visited by many different putative pollinator species, and pollinating insects tend to visit many plant hosts. This means that diffuse co-evolution is a much more likely driver of speciation in these communities. So, the standard phylogenetic methods for evaluating co-evolution aren’t applicable in most plant-pollinator interactions. Also, many plant-pollinator communities involve insect species for which we do not yet have fully resolved phylogenies. Continue reading →

Introducing fishtree and fishtreeoflife.org

Posted on April 24, 2019 by Chris Grieves

This post was originally published on Jonathan Chang’s blog.

In our recent publication (Rabosky et al. 2018) we assembled a huge phylogeny of ray-finned fishes: the most comprehensive to date! While all of our data are accessible via Dryad, we felt like we could go the extra mile to make it easy to repurpose and reuse our work. I’m pleased to report that this effort has resulted in two resources for the community: the Fish Tree of Life website, and the fishtree R package. The package is available on CRAN now, and you can install it with:

install.packages("fishtree")

The source is on GitHub in the repository jonchang/fishtree. The manuscript describing these resources has been published in Methods in Ecology and Evolution (Chang et al. 2019).

Continue reading →

Issue 10.4: Bayesian Models, Isoscapes, Camera Traps and More

Posted on April 4, 2019 by Chris Grieves

The April issue of Methods is now online!

This month we’re thinking about hierarchical Bayesian models and Approximate Bayesian Computation, improving ecological niche models, and learning how to make our own Environmental Microcontroller Units (more on that below). We’ve got articles on Phylogenetics, Space (not outer space), Camera Traps and much more. Plus, there are six papers that are completely free to everybody, no subscription required!

Find out a little more about the new issue of Methods in Ecology and Evolution (including details about the bobcat on this month’s cover) below. Continue reading →

Phylogenetic Tip Rates: How Well Can We Estimate Diversification?

Posted on March 29, 2019 by Chris Grieves

Post provided by Pascal Title and Dan Rabosky

Analyzing diversification rate heterogeneity across phylogenies allows us to explore all manner of questions, including why Australia has such an incredible diversity of lizards and snakes.

Within the tree of life there are differences in speciation and extinction rates over time and across lineages. Biologists have long been interested in how speciation rates change as a function of ecological opportunity or whether key innovations lead to increases in the rate of speciation. Exploring this rate variation and examining how clades differ in terms of their diversification dynamics can help us to understand why species diversity varies so dramatically in time and space. Learning more about the relationship between traits and diversification rates is especially important because it has the potential to reveal the causes of pervasive variation in species richness among clades and across geographic regions.

Several different classes of methods are available for studying the effects of species traits on lineage diversification rates. These include state-dependent diversification models (e.g., BiSSE, QuaSSE, HiSSE) and several non-model-based approaches. In our article – ‘Tip rates, phylogenies and diversification: What are we estimating, and how good are the estimates?’ – we assessed the accuracy of a number of model-free metrics (the DR statistic, node density metric, inverse of terminal branch lengths) and model-based approaches (Bayesian Analysis of Macroevolutionary Mixtures, BAMM) to determine how they perform under a variety of different types of rate heterogeneity. The “tip rates” using these approaches have become widely used for a few reasons, including ease of computation and how easy it is to pair them with other types of data. Continue reading →

Crossing the Palaeontological-Ecological Gap

Posted on August 30, 2018 by Chris Grieves

Today is the first day of the Crossing the Palaeontological-Ecological Gap (CPEG) conference. The aim of the conference is to open a dialogue between palaeontologists and ecologists who work on similar questions but across vastly different timescales. This splitting of temporal scales tends to make communication, data integration and synthesis in ecology harder. A lot of this comes from the fact that palaeontologists and ecologists tend to publish in different journals and attend different meetings.

Methods in Ecology and Evolution is one of few ecological journals that attracts submissions from both ecologists and palaeontologists. To highlight this, we’ve released a Virtual Issue, also called Crossing the Palaeontological-Ecological Gap. Continue reading →

The babette R Package: How to Sooth the Phylogenetic BEAST2

Posted on June 25, 2018 by Chris Grieves

Post provided by Richel Bilderbeek

What is babette?

‘babette‘ is an R package that works with the popular phylogenetic tool BEAST2. BEAST2 uses one or more alignments and a model setup to create a Bayesian posterior of jointly estimated model parameters and phylogenies.

babette lets you call BEAST2 from an R script. This makes it easier to explore models and/or alignments than using the graphical user interface programs that BEAST2 provides. It will also help you to improve the reproducibility of your work with BEAST2.

babette Tutorial Videos

If you’re new to phylogentic analyses, the video ‘babette demo‘ demonstrates the package. It has all of the information that you need to be able to start using the package

Continue reading →

A New Method for Computing Evolutionary Rates and Rate Shifts

Posted on February 12, 2018 by Chris Grieves

Post provided by Pasquale Raia

Phylogenetic Effects

Today, everyone knows about the importance of accounting for phylogenetic effects when it comes to understanding trait evolution. How to account for phylogenetic effects is another matter though.

A couple of years ago, I was having a discussion on the R-sig-phylo blog and dared to define the Brownian Motion (BM) as kind of a null hypothesis that more realistic scenarios should be compared to. Maybe I crossed a line or made too simplistic a statement (see Adams and Collyer’s article in Systematic Biology for an explanation of why this matter is far trickier and more complicated than my reply suggested). The point is, my comment was hotly contested and a colleague ‘put the onus on me’ to do something better than the almighty (emphasis mine) BM.

The RRphylo method was my attempt to do just that. It may not be better than BM, but it is different. Often, that can be exactly what you need. Continue reading →

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Tag Archives: phylogenetics