Avoiding genetic rescue not justified on genetic grounds

12 03 2015
Genetics to the rescue!

Genetics to the rescue!

I had the pleasure today of reading a new paper by one of the greatest living conservation geneticists, Dick Frankham. As some of CB readers might remember, I’ve also published some papers with Dick over the last few years, with the most recent challenging the very basis for the IUCN Red List category thresholds (i.e., in general, they’re too small).

Dick’s latest paper in Molecular Ecology is a meta-analysis designed to test whether there are any genetic grounds for NOT attempting genetic rescue for inbreeding-depressed populations. I suppose a few definitions are in order here. Genetic rescue is the process, either natural or facilitated, where inbred populations (i.e., in a conservation sense, those comprising too many individuals bonking their close relatives because the population in question is small) receive genes from another population such that their overall genetic diversity increases. In the context of conservation genetics, ‘inbreeding depression‘ simply means reduced biological fitness (fertility, survival, longevity, etc.) resulting from parents being too closely related.

Seems like an important thing to avoid, so why not attempt to facilitate gene flow among populations such that those with inbreeding depression can be ‘rescued’? In applied conservation, there are many reasons given for not attempting genetic rescue: Read the rest of this entry »





We treat our wildlife like vermin

24 09 2014
Just a little of the dog fence's carnage and cruelty at work.

Just a little of the dog fence’s carnage and cruelty at work.

I’ve pointed out in several posts on ConservationBytes.com just how badly Australia is doing in the environmental stakes, with massive deforestation continuing since colonial times, feral predators and herbivores blanketing the continent, inadequate protected areas, piss-weak policies and a government at war with its own environment. Despite a few recent wins in marine conservation, Australia has a dreadful track record.

Now in another monumental demonstration of stupidity, corruption and colonial-era attitudes toward native wildlife, Western Australia has outdone itself by sneaking through legislation to extend its so-called ‘Barrier Fence’ in an effort to isolate its marginal farmland from dingoes, emus and other ‘nuisance’ species.

As I and several others have pointed out before, the mere existence of the record-breaking dingo fence is not only counter-productive, it is expensive and utterly archaic. It should be torn down entirely.

Instead, the Western Australian government wants to extend the national fence, and they’ve approved the plan it without going through any of the appropriate checks in the system. Its environmental impacts have not been adequately assessed, nor has the public been given the opportunity to oppose the plans. In my view, the people responsible for this act should go to gaol.

In a recent paper led by Keith Bradby entitled Ecological connectivity or Barrier Fence? Critical choices on the agricultural margins of Western Australia, we show how the Western Australia state government has not followed any of its own environmental legislation and rushed through these idiotic proposals. If you do not subscribe to Ecological Management and Restoration, you can obtain a copy of the paper by e-mailing Keith or me. Read the rest of this entry »





World Heritage Species

17 08 2014

horseshoe crabHaving just attended the Baker & Stebbins Legacy Symposium on Invasion Genetics in Pacific Grove, California, I have had a rare bit of leisure time between my book-writing commitments and operating in conference mode. It’s summer here in California, so I’ve taken the opportunity to read a bit of The New Yorker in my accommodation. It is indeed a pleasure to have these micro-moments of ‘leisure’ reading. As it turns out though, work subjects are never far from my mind as I do this.

So it interested me greatly when I read another fantastic article in the ‘Yorker about horseshoe crabs, and their precarious state despite having survived half a billion years on this planet. While I was generally interested in the science, biomedical applications, conservation and systematics of the species, what really caught my eye was the proposal to list them as a ‘World Heritage Species’.

A what? Never heard of that classification, you say? Neither had I. Not to worry though – it doesn’t exist yet. Read the rest of this entry »





50/500 or 100/1000 debate not about time frame

26 06 2014

Not enough individualsAs you might recall, Dick Frankham, Barry Brook and I recently wrote a review in Biological Conservation challenging the status quo regarding the famous 50/500 ‘rule’ in conservation management (effective population size [Ne] = 50 to avoid inbreeding depression in the short-term, and Ne = 500 to retain the ability to evolve in perpetuity). Well, it inevitably led to some comments arising in the same journal, but we were only permitted by Biological Conservation to respond to one of them. In our opinion, the other comment was just as problematic, and only further muddied the waters, so it too required a response. In a first for me, we have therefore decided to publish our response on the arXiv pre-print server as well as here on ConservationBytes.com.

50/500 or 100/1000 debate is not about the time frame – Reply to Rosenfeld

cite as: Frankham, R, Bradshaw CJA, Brook BW. 2014. 50/500 or 100/1000 debate is not about the time frame – Reply to Rosenfeld. arXiv: 1406.6424 [q-bio.PE] 25 June 2014.

The Letter from Rosenfeld (2014) in response to Jamieson and Allendorf (2012) and Frankham et al. (2014) and related papers is misleading in places and requires clarification and correction, as follows: Read the rest of this entry »





We’re sorry, but 50/500 is still too few

28 01 2014

too fewSome of you who are familiar with my colleagues’ and my work will know that we have been investigating the minimum viable population size concept for years (see references at the end of this post). Little did I know when I started this line of scientific inquiry that it would end up creating more than a few adversaries.

It might be a philosophical perspective that people adopt when refusing to believe that there is any such thing as a ‘minimum’ number of individuals in a population required to guarantee a high (i.e., almost assured) probability of persistence. I’m not sure. For whatever reason though, there have been some fierce opponents to the concept, or any application of it.

Yet a sizeable chunk of quantitative conservation ecology develops – in various forms – population viability analyses to estimate the probability that a population (or entire species) will go extinct. When the probability is unacceptably high, then various management approaches can be employed (and modelled) to improve the population’s fate. The flip side of such an analysis is, of course, seeing at what population size the probability of extinction becomes negligible.

‘Negligible’ is a subjective term in itself, just like the word ‘very‘ can mean different things to different people. This is why we looked into standardising the criteria for ‘negligible’ for minimum viable population sizes, almost exactly what the near universally accepted IUCN Red List attempts to do with its various (categorical) extinction risk categories.

But most reasonable people are likely to agree that < 1 % chance of going extinct over many generations (40, in the case of our suggestion) is an acceptable target. I’d feel pretty safe personally if my own family’s probability of surviving was > 99 % over the next 40 generations.

Some people, however, baulk at the notion of making generalisations in ecology (funny – I was always under the impression that was exactly what we were supposed to be doing as scientists – finding how things worked in most situations, such that the mechanisms become clearer and clearer – call me a dreamer).

So when we were attacked in several high-profile journals, it came as something of a surprise. The latest lashing came in the form of a Trends in Ecology and Evolution article. We wrote a (necessarily short) response to that article, identifying its inaccuracies and contradictions, but we were unable to expand completely on the inadequacies of that article. However, I’m happy to say that now we have, and we have expanded our commentary on that paper into a broader review. Read the rest of this entry »





Cleaning up the rubbish: Australian megafauna extinctions

15 11 2013

diprotodonA few weeks ago I wrote a post about how to run the perfect scientific workshop, which most of you thought was a good set of tips (bizarrely, one person was quite upset with the message; I saved him the embarrassment of looking stupid online and refrained from publishing his comment).

As I mentioned at the end of post, the stimulus for the topic was a particularly wonderful workshop 12 of us attended at beautiful Linnaeus Estate on the northern coast of New South Wales (see Point 5 in the ‘workshop tips’ post).

But why did a group of ecological modellers (me, Barry Brook, Salvador Herrando-Pérez, Fréd Saltré, Chris Johnson, Nick Beeton), ancient DNA specialists (Alan Cooper), palaeontologists (Gav Prideaux), fossil dating specialists (Dizzy Gillespie, Bert Roberts, Zenobia Jacobs) and palaeo-climatologists (Michael Bird, Chris Turney [in absentia]) get together in the first place? Hint: it wasn’t just the for the beautiful beach and good wine.

I hate to say it – mainly because it deserves as little attention as possible – but the main reason is that we needed to clean up a bit of rubbish. The rubbish in question being the latest bit of excrescence growing on that accumulating heap produced by a certain team of palaeontologists promulgating their ‘it’s all about the climate or nothing’ broken record.

Read the rest of this entry »





DNA barcoding plants with citizen science

28 08 2013

hikingI was contacted recently by Oscar Jaslowski of Microryza (a web platform that allows scientists to post research  ideas and collect contributions from web visitors) about a project getting underway in Alaska by Ellen Jorgensen of Genspace. He suggested it might make a good post for ConservationBytes.com, and I agreed. Thanks for the contribution, Ellen & Oscar.

There’s nothing so final as watching the bush pilot take off in his tiny plane, leaving you stranded in the Alaskan backcountry. We had plenty of food for a three-day expedition, but no satellite phone or any other way to contact anyone. In Alaska, the phrase ‘primordial indifference’ pretty much sums up your relationship with the vast, glacier-carved landscape. Mother Nature does not care if an ant like you lives or dies.

Our destination, the Skolai Valley, is located about 480 km (300 miles) east of Anchorage, in the heart of Wrangell-St. Elias National Park. At a whopping 5.3 million hectares (13 million acres), it is the largest national park in the United States, and probably one of the least-visited. Much of its forbidding territory is snow-covered and similar to the Himalayas. In fact, the size of the massive ice fall that towers over the town of McCarthy, the origin of our flight, is exceeded only by one near Mt. Everest. But winding through the glaciers and snowfields are alpine valleys that are a backpacker’s dream. And Genspace, the nonprofit science-based organisation that I direct, was lucky enough to have received funding in 2012 to launch this expedition to Skolai.

Our  mission: to barcode wild Alaskan plant life. Two of us headed down into the river valley and the other two climbed up to the level of the mountain pass to survey more alpine vegetation. We were carrying portable plant presses – normally something too bulky for backpacking, but necessary for this trip. Read the rest of this entry »








Follow

Get every new post delivered to your Inbox.

Join 7,630 other followers

%d bloggers like this: