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:
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.
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 →
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?
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 →
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:
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).
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.
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.
‘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
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 →