Monthly Archives: June 2013

The Cliff

Tenerife 2008 057 - students on the Aeonium field

Over the past few months I’ve been thinking a lot about PhDs and doctoral students, and our expectations of them, specifically in contributing to cutting edge biodiversity science.  In part this is because August 2013 will mark the 20th anniversary of the oral examination (“viva”) of my PhD at Oxford Brookes University.  The viva (short for the Latin phrase viva voce or “living voice”) is a peculiarly British method of examining PhD students that differs significantly from its (often public) counterpart in the rest of Europe and Scandinavia, and even more so from its equivalent in North America and the rest of the world.

For those of you unfamiliar with the viva process, I can recommend Simon Leather’s recent posting on the topic.

Since 1993 I’ve had the honour of acting as an examiner for 22PhD theses (4 at the University of Northampton, 18 externally) including two so far this year;  I’ve yet to turn down an opportunity to examine a PhD as it’s flattering to be asked and (more importantly) a great opportunity to see new ideas and data being generated by minds younger than mine.

One of the things that has exercised me recently is how much knowledge the average PhD student in my main discipline of pollination ecology actually has to get to grips with while doing the background research for their topic.  I wondered how this had changed since my time as a postgrad in the 1990s, and how the expectations of my own PhD examiners had changed since the 1970s.  So, using the wildcard term “pollinat*” in Web of Science I searched the contents of seven journals (Oecologia, Ecology, Journal of Ecology, Oikos, Annals of Botany, American Journal of Botany, & American Naturalist) that have published a significant proportion of the literature on pollination ecology over the past forty-odd years.

Of course I expected to see an increase in the number of papers on this topic being published per year over that time period, but not the two orders of magnitude difference that I found.  A PhD student studying pollination ecology in the early 1970s would be confronted with fewer than 10 papers on the topic coming from these seven journals whilst at the present time it’s averaging around 130 per year:

Pollination papers line graph

So it’s no wonder that PhD theses are tending to become more focussed as topics become more specialised.  So far, so expected.  But what I think is more interesting is the shape of the graph; why is there such a steep increase in the number of published papers in 1991?  I’ve nicknamed this point “The Cliff” because of its shape, and also because it seems to symbolise an intellectual barrier to be surmointed: an ability to read and synthesise a lot more information than was available prior to the early 1990s.  What is the reason for The Cliff?  Do other areas of ecology and evolution demonstrate a similar pattern in their historical rates of publication?  I see a link here to a discussion going on over at the Dynamic Ecology blog about the most cited ecology papers of the past few decades, and particularly the fact that “big ideas” papers are becoming less cited than review papers.  Perhaps it’s because we need these reviews to keep on top of literature that we’ve not got round to reading!

But that doesn’t explain why 1991 represents a step change for publishing in the field.  I’d be interested to hear the views of others working in pollination ecology.  What happened in the late 1980s to stimulate such an interest in doing research into plant-pollinator interactions?  Was it the publication of some key papers or books?  Did more funding become available specifically for work in this area?

Rewilding – inside and out

2012-05-11 08.39.32

The last blog entry I posted mentioned the reintroduction of red kites to England, surely one of this country’s most impressive conservation success stories of the past few decades.  Such reintroductions can be seen as one minor aspect of the “rewilding” programme being advocated by some conservation biologists.  In its most extreme form, radical rewilders advocate populating whole landscapes with large herbivores and predators that once roamed these regions but are now locally extinct, either because of human hunting pressure or environmental change (sort of Jurassic Park backed up with real science).  The idea is that reintroducing such animals results in more “natural” habitats in which ecological processes are returned to a more pristine state and biodiversity is maximised.  

There are arguments for and against rewilding in all its forms, and four recent coincidental occurrences make rewilding a topical subject for this blog.  

Coincidence one is that the Guardian newspaper has posted a great animated video about rewilding, voiced by environmental writer George Monbiot, whose work I’ve mentioned previously.  It’s an interesting overview of rewilding, if a bit simplistic; and (spoiler alert!) I’m sure I’d not want to jump naked into a river with hippos!  

Coincidence two is that I’m currently reading Once and Future Giants: What Ice Age Extinctions Tell Us About the Fate of Earth’s Largest Animals by Sharon Levy, which discusses some of the more radical rewilding notions that have been proposed, such as introducing elephants, lions, zebra and other African megafauna to North America, as stand-ins for their Pleistocene cousins which may (or may not) have been over hunted by the ancestors of native Americans.  That’s a controversial topic, as you might imagine, and it’s a book that’s well worth reading, not least because it effectively captures the atmosphere of the various camps of scientists promoting the hypotheses they personally support.

Coincidence three is that a paper was published in the journal Science last week which provides evidence for what can happen when larger animals (often the first to go locally extinct) are removed from ecological communities.  In this case, the seeds of a dominant, bird dispersed palm tree have evolved to be significantly smaller in size in those populations where the largest seed dispersing birds have been removed.  All of this has happened in the last 1o0 years or so, remarkably rapid evolution.  One of the authors, Spanish scientist Pedro Jordano, gives an account of the paper in his blog.  The study is one of the few published that links loss of biodiversity of species interactions to their ecological and evolutionary consequences, and has generated a lot of media attention.

The final coincidence is that a short review paper has finally appeared which I co-authored with Duke University medical researcher William Parker entitled Evolutionary biology and anthropology suggest biome reconstitution as a necessary approach toward dealing with immune disorders“.  You can take a look at the paper (or at least read the abstract) yourself.  But in essence the review places William’s Biome Depletion Theory in a broader perspective of how the loss of species with which Homo sapiens would normally interact (in this case gut worms of various types) can have profund knock-on effects for human health and may explain the epidemics of some conditions that are currently prevalent within industrialised societies.  More controversially, the review advocates that we begin to routinely rewild our gut fauna by selectively introducing one or more types of laboratory-bred worms to the guts of children.  There’s already a lot of discussion around this topic but one day in the future such procedures may become no more unusual than standard childhood vaccinations.

Having said that, there were enough problems convincing land owners that reintroducing beavers was a good thing in the Scottish Highlands, whilst similar plans for wolves and bears have stalled; reintroduction of tape worms to their children’s lowlands will probably take even more convincing.