An appeal to extinction chronologists

2 06 2015

u7Pi3Extinction is forever, right? Yes, it’s true that once the last individual of a species dies (apart from insane notions that de-extinction will do anything to resurrect a species in perpetuity), the species is extinct. However, the answer can also be ‘no’ when you are limited by poor sampling. In other words, when you think something went extinct when in reality you just missed it.

Most of you are familiar with the concept of Lazarus1 species – when we’ve thought of something long extinct that suddenly gets re-discovered by a wandering naturalist or a wayward fisher. In paleontological (and modern conservation biological) terms, the problem is formally described as the ‘Signor-Lipps’ effect, named2 after two American palaeontologists, Phil Signor3 and Jere Lipps. It’s a fairly simple concept, but it’s unfortunately ignored in most palaeontological, and to a lesser extent, conservation studies.

The Signor-Lipps effect arises because the last (or first) evidence (fossil or sighting) of a species presence has a nearly zero chance of heralding its actual timing of extinction (or appearance). In paleontological terms, it’s easy to see why. Fossilisation is in fact a nearly impossible phenomenon – all the right conditions have to be in place for a once-living biological organism to be fossilised: it either has to be buried quickly, in a place where nothing can decompose it (usually, an anoxic environment), and then turned to rock by the process of mineral replacement. It then has to resist transformation by not undergoing metamorphosis (e.g., vulcanism, extensive crushing, etc.). For more recent specimens, preservation can occur without the mineralisation process itself (e.g., bones or flesh in an anoxic bog). Then the bloody things have to be found by a diligent geologist or palaeontologist! In other words, the chances that any one organism is preserved as a fossil after it dies are extremely small. In more modern terms, individuals can go undetected if they are extremely rare or remote, such that sighting records alone are usually insufficient to establish the true timing of extinction. The dodo is a great example of this problem. Remember too that all this works in reverse – the first fossil or observation is very much unlikely to be the first time that the species was there. Read the rest of this entry »





Dawn of life

18 05 2015
Looking east toward the northern Flinders Ranges from Ediacara Conservation Park. © CJA Bradshaw

Looking east toward the northern Flinders Ranges from Ediacara Conservation Park. © CJA Bradshaw

I’ve had one of the most mind-blowing weeks of scientific discovery in my career, and it’s not even about a subject from within my field.

As some of you might know, I’ve been getting more and more interested in palaeo-ecology over the past few years. I’m fascinated by the challenge of reconstructing past communities and understanding how and why they changed. It’s a natural progression for someone interested in modern extinction dynamics.

Most of my recent interests have focussed on palaeo-communities of the Late Quaternary, and mainly in the range of 100 thousand years ago to the present. We’ve started publishing a few things in this area, and I can confirm that they’ll be plenty more to come in the following months and years. Despite plenty more to do in the youngest of palaeo-communities, I’ve now been bitten by the deep-time bug.

The giant Dickinsonia rex - a flat, worm-like discoid animal. © D. García-Bellido

The giant Dickinsonia rex – a flat, worm-like discoid animal. © D. García-Bellido

When I write ‘deep time’, I bloody well mean it: back to 580 million years, to be accurate. This is the time before the great Cambrian explosion of life popularised by the late Stephen Jay Gould in his brilliant book, Wonderful Life1,2. I’m talking about the Ediacaran period from 635-541 million years ago.

I’ve lived in South Australia now for over seven years, but it was only in the last few that I realised the Ediacaran was named after the Ediacara Hills in the northern Flinders Ranges some 650 km north of Adelaide where I live, and it wasn’t until last week that I had the extremely gratifying privilege of visiting the region with some of the world’s top Ediacaran specialists. If you have even the remotest interest in geological time and the origin of life on Earth, you should make a pilgrimage to the Flinders Ranges at some point before you die.

Read the rest of this entry »





Australia’s perfect storm of negligence

17 03 2015

If, for the purposes of some sick and twisted thought experiment, you were to design policies that would ensure the long-term failure of a wealthy, developed nation, you wouldn’t have to look farther than Australia’s current recipe for future disaster. I’m not trying to be provocative, but the warning signs are too bold and flashy to ignore. Let’s just run through some of the main ones:

1. As the lambasted and thoroughly flawed 2015 Intergenerational Report clearly demonstrates, our current government has no idea about the future threats of climate change. Dragged kicking and screaming into only a symbolic recognition of some ‘distant and currently irrelevant problem’, the Abbott-oir and his intergenerational criminals are well known for killing the carbon-pricing scheme, dismantling the Department of Climate Change, pulling out of major international talks on climate-change mitigation and installing a half-arsed, ineffective policy that will do nothing to stem our emissions. Combine that with comments like “coal is good for humanity“, and it’s easy to see how our current leaders have little idea about the future mess they’re creating.

2. Not content just to kick the shit out of any meaningful climate action, our government has also turned its back on any renewable energy target, and facilitated the fossil-fuel barons to dig more coal out of the ground. While South Australia’s Royal Commission on the nuclear fuel cycle is a welcome candle in the climate change-mitigation darkness here, it is far from becoming a national priority any time soon.

3. As has been well documented, the Abbott-oir ship of fools has also done whatever it can to turn back decades of environmental protections in less than six months of taking office. Everything from opening up national parks for exploitation, failing to protect marine sanctuaries, limiting environmental checks to promoting logging in World Heritage Areas, there is little room for hope that our crumbling environmental system will improve at all in the near to long term. Read the rest of this entry »





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 »





It’s all about the variation, stupid

12 01 2015

val-1-3It is one of my long-suffering ecological quests to demonstrate to the buffoons in government and industry that you can’t simply offset deforestation by planting another forest elsewhere. While it sounds attractive, like carbon offsetting or even water neutrality, you can’t recreate a perfectly functioning, resilient native forest no matter how hard you try.

I’m not for a moment suggesting that we shouldn’t reforest much of what we’ve already cut down over the last few centuries; reforestation is an essential element of any semblance of meaningful terrestrial ecological restoration. Indeed, without a major commitment to reforestation worldwide, the extinction crisis will continue to spiral out of control.

What I am concerned about, however, is that administrators continue to push for so-called ‘biodiversity offsets’ – clearing a forest patch here for some such development, while reforesting or even afforesting another degraded patch there. However, I’ve blogged before about studies, including some of my own, showing that one simply cannot replace primary forests in terms of biodiversity and long-term carbon storage. Now we can add resilience to that list.

While I came across this paper a while ago, I’ve only found the time to blog about it now. Published in PLoS One in early December, the paper Does forest continuity enhance the resilience of trees to environmental change?1 by von Oheimb and colleagues shows clearly that German oak forests that had been untouched for over 100 years were more resilient to climate variation than forests planted since that time. I’ll let that little fact sink in for a moment … Read the rest of this entry »





Help Hawaii’s hyper-threatened birds

6 01 2015
Puaiohi or small Kaua'i thrush. Photo by Lucas Behnke

Puaiohi or small Kaua’i thrush. Photo by Lucas Behnke

You wouldn’t want to be a bird in Hawaii. There are more avian species threatened with extinction there than anywhere else in the USA. After humans arrived, some 70+ species have become extinct, and 31 are listed as threatened with extinction. In addition, 43% of 157 species are not native; among land birds, 69% are introduced species.

My friend, Cali Crampton asked me to promote their new crowdfunding project to reduce the threat of feral rats on Hawaiian birds. Please help if you can.

The Kaua‘i Forest Bird Recovery Project, a collaborative project of the Hawaii Department of Land and Natural Resources, Division of Forestry and Wildlife, the University of Hawaii Pacific Cooperative Studies Unit, and Garden Island Research and Development, has announced the launch of a crowdfunding and outreach campaign to generate support for protecting the native birds of Kaua’i by controlling rats with humane, self-resetting rat traps.

The campaign, named “Birds, not Rats!” runs through to 31 January 2015, with goals of increasing awareness of the threats that rats pose to birds and native ecosystems, and raising at least $10,000 for rat control through many small, individual donations.

Hawai’i is at the epicentre of the current global extinction crisis. Of the original 130+ native Hawaiian bird species, many have been lost forever, and only 11 are not yet endangered. Today, Kaua’i is home to eight native forest bird species, three of which are federally listed as endangered: the puaiohi or small Kaua’i thrush, the akeke’e or Kaua’i akepa, and the akikiki or Kaua’i creeper. Populations of these birds have plummeted as much as 90% in the last five years; the akikiki and the puaiohi now number fewer than 500 individuals, and the akeke’e numbers fewer than 1000 individuals. The Kaua’i Forest Bird Recovery Project’s goal is to reverse these declines. Read the rest of this entry »





Psychological toll of being a sustainability scientist

8 12 2014

depressed scientistLike many academics, I’m more or less convinced that I am somewhere on the mild end of the autism spectrum. No, I haven’t been diagnosed and I doubt very much that my slight ‘autistic’ tendencies have altered my social capacity, despite my wife claiming that I have only two emotions – angry or happy. Nor have they engendered any sort of idiot savant mathematical capability.

But I’m reasonably comfortable with mathematics, I can do a single task for hours once it consumes my attention, and I’m excited about discovering how things work. And I love to code. Rather than academics having a higher innate likelihood of being ‘autistic’, I just think the job attracts such personalities.

In the past few years though, my psychological state is probably less dictated by the hard-wiring of my ‘autidemic’ mind and more and more influenced by the constant battery of negative information my brain receives.

Read the rest of this entry »








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