Colour polymorphism in Protea

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F1.medium.gifYes, that's the British spelling of "color," and there's a reason for that. Jane Carlson and I have a paper that just appeared in Proceedings of the Royal Society Series B about color polymorphism in Protea. Since the Royal Society is a British society, we use British spellings throughout the paper.

The photograph to the left is of Protea compacta. It's the cover photo for this issue of the Proceedings. Jane took it in the Kleinmond Coast and Mountain Nature Reserve. You can find a little more information about it at the Proceedings web site.

Here's the title, abstract, and citation for the paper.

Extrapolating from local ecological processes to genus-wide patterns in colour polymorphism in South African Protea

Polymorphic traits are central to many fundamental discoveries in evolution, yet why they are found in some species and not others remains poorly understood. We use the African genus Protea--within which more than 40% of species have co-occurring pink and white floral colour morphs--to ask whether convergent evolution and ecological similarity could explain the genus-wide pattern of polymorphism. First, we identified environmental correlates of pink morph frequency across 28 populations of four species. Second, we determined whether the same correlates could predict species-level polymorphism and monomorphism across 31 species. We found that pink morph frequency increased with elevation in Protea repens and three section Exsertae species, increased eastward in P. repens, and increased with seed predation intensity in section Exsertae. For cross-species comparisons, populations of monomorphic pink species occurred at higher elevations than populations of monomorphic white species, and 18 polymorphic species spanned broader elevational gradients than 13 monomorphic species. These results suggest that divergent selection along elevational clines has repeatedly favoured polymorphism, and that more uniform selection in altitudinally restricted species may promote colour monomorphism. Our findings are, to our knowledge, the first to link selection acting within species to the presence and absence of colour polymorphism at broader phylogenetic scales.

Jane E. Carlson , Kent E. Holsinger

282; 2015

DOI: 10.1098/rspb.2015.0583

A new paper from our Dimensions of Biodiversity project has just appeared in The American Naturalist. Here's the abstract:

Functional Traits in Parallel Evolutionary Radiations and Trait-Environment Associations in the Cape Floristic Region of South Africa

Evolutionary radiations with extreme levels of diversity present a unique opportunity to study the role of the environment in plant evolution. If environmental adaptation played an important role in such radiations, we expect to find associations between functional traits and key climatic variables. Similar trait-environment associations across clades may reflect common responses, while contradictory associations may suggest lineage-specific adaptations. Here, we explore trait-environment relationships in two evolutionary radiations in the fynbos biome of the highly biodiverse Cape Floristic Region (CFR) of South Africa. Protea and Pelargonium are morphologically and evolutionarily diverse genera that typify the CFR yet are substantially different in growth form and morphology. Our analytical approach employs a Bayesian multiple-response generalized linear mixed-effects model, taking into account covariation among traits and controlling for phylogenetic relationships. Of the pairwise trait-environment associations tested, 6 out of 24 were in the same direction and 2 out of 24 were in opposite directions, with the latter apparently reflecting alternative life-history strategies. These findings demonstrate that trait diversity within two plant lineages may reflect both parallel and idiosyncratic responses to the environment, rather than all taxa conforming to a global-scale pattern. Such insights are essential for understanding how trait-environment associations arise and how they influence species diversification.

American Naturalist 185:525-537; 2015. doi: 10.1086/680051

Dryad data: doi: 10.5061/dryad.sc286

In Shanghai

I'm in Shanghai until Saturday, and I'll be wearing my Deans and Directors of Graduate Studies (DDoGS) of Universitas 21 institutions are holding their annual meeting. There's a workshop on Research Supervisor Support and Development that starts tomorrow that I'm especially looking forward to.1
Research supervision has been identified by graduate students as the single most influential factor on PhD satisfaction and has also been linked with time to completion (Taylor and Beasley 2005, Lee 2013). The significance and impact of good supervisory practice is not under dispute, however, a consensus on a definition of what good supervisor practice is and also on the kinds of support to be provided by universities, has proven difficult to reach and is often ambiguous.
I hope to learn a lot that I'll be able to share with colleagues at UConn.

Listing the monarch butterfly as endangered?

The U.S. Fish and Wildlife Service just announced that it will review the status of a subspecies of the monarch butterfly to determine whether it qualifies for protection under the Endangered Species Act. Here is the text of the e-mail announcement I received earlier today:

Service Initiates Status Review of Monarch Butterfly under the Endangered Species Act

The U.S. Fish and Wildlife Service today announced it will be conducting a status review of the monarch butterfly under the Endangered Species Act (ESA). The Service has determined that a petition from the Center for Biological Diversity, the Center for Food Safety, the Xerces Society for Invertebrate Conservation and Dr. Lincoln Brower to list a subspecies of monarch (Danaus plexippus plexippus) presents substantial information indicating that listing may be warranted.

Monarch butterflies are found throughout the United States and some populations migrate vast distances across multiple generations each year. Many monarchs fly between the U.S., Mexico and Canada - a journey of over 3,000 miles. This journey has become more perilous for many monarchs because of threats along their migratory paths and on their breeding and wintering grounds. Threats include habitat loss - particularly the loss of milkweed, the monarch caterpillar's sole food source - and mortality resulting from pesticide use. Monarch populations have declined significantly in recent years.

The Service will now conduct a status review to determine whetherlisting is warranted. To ensure this status review is comprehensive, the Service is requesting scientific and commercial data and other information through a 60-day public information period. Specifically, the Service seeks information including:
  • The subspecies' biology, range and population trends, habitat
    requirements, genetics and taxonomy;
  • Historical and current range, including distribution patterns;
  • Historical and current population levels and current and
    projected trends;
  • The life history or behavior of the monarch butterfly that has
    not yet been documented;
  • Thermo-tolerance range and microclimate requirements of the
    monarch butterfly;
  • Past and ongoing conservation measures for the subspecies, its
    habitat or both;  and,
  • Factors that are the basis for making a listing determination
    under section 4(a) of the ESA;
The notice will publish in the Federal Register December 31, 2014, and it is requested that information be received by March 2, 2015. To view the notice and submit information, visit docket
number FWS-R3-ES-2014-0056.

For more information on the ESA's petition process, visit

Lecture notes in population genetics

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Some of you know that the lecture notes I use for my graduate course in population genetics (EEB 5348) are available either as individual HTML or PDF pages from the lecture notes page on the course website or as a single-volume, book-like PDF from Figshare.

This year I'm making them even a little more available. I just created a public Github repository containing the LaTeX source and associated files. I've licensed the notes under a Creative Commons Attribution-ShareAlike license for many years, but now it will be a bit easier for anyone who's interested to use my notes directly.