Projecting global deaths from covid19

18 03 2020

covid

I know that it’s not the best way to project expected deaths from a pandemic disease, but being something of a demographer, I just couldn’t help myself.

I therefore took the liberty of punching in some basic probabilities into our world population model to see how many people could potentially die from covid19. But this is not an epidemiological model, so I’m probably vastly over-estimating the total death rates.

Nonetheless, the results were revealing.

I first took the expected mortality by age class based on the Chinese data so far. I then assumed a worst-case scenario of a 60% infection rate (i.e., 3 out of 5 of us will eventually catch the virus). I assumed these values across the entire globe (not taking into account greater or lesser susceptibility or probability of death among countries or regions).

I also considered two more scenarios: (i) double the mortality rate (in each age class), and (ii) the disease outbreak lasting two years instead of just one.

The graph below shows the four different outcomes based on these scenarios relative to the baseline (no covid): Read the rest of this entry »





Global warming causes the worst kind of extinction domino effect

25 11 2018

Dominos_Rough1-500x303Just under two weeks ago, Giovanni Strona and I published a paper in Scientific Reports on measuring the co-extinction effect from climate change. What we found even made me — an acknowledged pessimist — stumble in shock and incredulity.

But a bit of back story is necessary before I launch into describing what we discovered.

Last year, some Oxbridge astrophysicists (David Sloan and colleagues) published a rather sensational paper in Scientific Reports claiming that life on Earth would likely survive in the face of cataclysmic astrophysical events, such as asteroid impacts, supernovae, or gamma-ray bursts. This rather extraordinary conclusion was based primarily on the remarkable physiological adaptations and tolerances to extreme conditions displayed by tardigrades— those gloriously cute, but tiny (most are around 0.5 mm long as adults) ‘water bears’ or ‘moss piglets’ — could you get any cuter names?

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Found almost everywhere and always (the first fossils of them date back to the early Cambrian over half a billion years ago), these wonderful little creatures are some of the toughest metazoans (multicellular animals) on the planet. Only a few types of extremophile bacteria are tougher.

So, boil, fry or freeze the Earth, and you’ll still have tardigrades around, concluded Sloan and colleagues.

When Giovanni first read this, and then passed the paper along to me for comment, our knee-jerk reaction as ecologists was a resounding ‘bullshit!’. Even neophyte ecologists know intuitively that because species are all interconnected in vast networks linked by trophic (who eats whom), competitive, and other ecological functions (known collectively as ‘multiplex networks’), they cannot be singled out using mere thermal tolerances to predict the probability of annihilation. Read the rest of this entry »





Postdoctoral position re-opened in Global Ecology

18 10 2017

women-are-better-codersI believe it is important to clarify a few things about the job advertisement that we are re-opening.

As many of you might recall, we advertised two positions in paleo-ecological modelling back in July — one in ecological networks, and the other in vegetation modelling.

We decided to do something a little unusual with the vegetation modelling position by only accepting applications from women. We did this expressly to increase the probability of attracting excellent women candidates, and to increase the number of women scientists in our lab.

I’m happy to say that we received many great applications for both positions, and whether or not it was related, most of the applicants for both positions were women (83%). As it turned out, we ended up offering the network position to a woman applicant, but we were unable to find an ideal candidate for the vegetation modelling job (i.e., the one that was originally targeting women only).

Our decision not to appoint anyone in the first round of applicants for the vegetation modelling position was clearly not related to the fact that it a woman-only position, mainly because we had so many excellent women candidates for both positions (and ended up hiring a woman for the position that was open to both genders). In other words, it seems to be a just one of those random things.

That said, we are still in need of a great vegetation modeller (or at least, someone who has the capacity to learn this knowledge), and so we have decided to re-open the announcement to both genders. However, it should go without saying that we particularly encourage women to apply.

The full details of the position, essential and desired criteria, and application process are available here (Vacancy Reference Number 17115). Note that the application closing date is 15 November 2017.

Please distribute this widely among your networks.

CJA Bradshaw





Two new postdoctoral positions in ecological network & vegetation modelling announced

21 07 2017

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With the official start of the new ARC Centre of Excellence for Australian Biodiversity and Heritage (CABAH) in July, I am pleased to announce two new CABAH-funded postdoctoral positions (a.k.a. Research Associates) in my global ecology lab at Flinders University in Adelaide (Flinders Modelling Node).

One of these positions is a little different, and represents something of an experiment. The Research Associate in Palaeo-Vegetation Modelling is being restricted to women candidates; in other words, we’re only accepting applications from women for this one. In a quest to improve the gender balance in my lab and in universities in general, this is a step in the right direction.

The project itself is not overly prescribed, but we would like something along the following lines of inquiry: Read the rest of this entry »





Job: Research Fellow in Palaeo-Ecological Modelling

13 04 2017

© seppo.net

I have another postdoctoral fellowship to advertise! All the details you need for applying are below.

KEY PURPOSE 

Scientific data such as fossil and archaeological records used as proxy to reconstruct past environments and biological communities (including humans) are sparse, often ambiguous or contradictory when establishing any consensus on timing or routes of initial human arrival and subsequent spread, the timing or extent of major changes in climate and other environmental perturbations, or the timing or regional pattern of biological extinctions.

The Research Fellow (Palaeo-Ecological Modelling) will assist in addressing these problems by developing state-of-the-art analytical and simulation tools to infer regional pattern of both the timing of human colonisation and megafauna extinction based on incomplete and sparse dataset, and investigating past environmental changes and human responses to identify their underlying causes and consequences on Australia’s landscapes, biodiversity and cultural history.

ORGANISATIONAL ENVIRONMENT 

The position will be based in the School of Biological Sciences in the Faculty of Science & Engineering at Flinders University. Flinders University boasts a world-class Palaeontology Research Group (PRG) and the new Global Ecology Research Laboratory that have close association with the research-intensive South Australian Museum. These research groups contribute to building a dynamic research environment that explores the continuum of environmental and evolutionary research from the ancient to modern molecular ecology and phylogeography. The School of Biological Sciences is an integrated community researching and teaching biology, and has a long history of science innovation. The appointee will join an interdisciplinary school of approximately 45 academic staff. The teaching and research activities of the School are supported by a range of technical and administrative infrastructure services.

KEY RESPONSIBILITIES

The key responsibilities and selection criteria identified for this position should be read in conjunction with the Flinders University Academic Profiles for the relevant academic classification (scroll down to Academic Profiles).

The Research Fellow (Palaeo-Ecological Modelling) will work under the direction of the Project Chief Investigator, and will be required to: Read the rest of this entry »





Job: Research Associate in Eco-epidemiological modelling

3 03 2017
myxo-rabbit

European rabbit infected with myxomatosis

Earlier this week I advertised two new PhD scholarships in palaeo-ecological modelling. Now we are pleased to advertise a six-month Research Associate position in eco-epidemiological modelling.

The position will be based in the School of Biological Sciences at Flinders University. Flinders University offers a dynamic research environment that explores the continuum of environmental and evolutionary research from the ancient to modern ecology. The School of Biological Sciences is an integrated community researching and teaching biology, and has a long history of science innovation.

Project background

Since 1996, Biosecurity South Australia has been running a capture-mark-recapture study on a European rabbit (Oryctolagus cuniculus) population located at Turretfield (~ 50 km north of Adelaide). Now into the 21st year, this is one of the world’s longest studies of its kind. Approximately every 8 weeks cage traps are reset and the population trapped over five days, with the captured rabbits weighed, sexed, tagged and blood-sampled. The study was established to investigate the epidemiology and efficacy of the two imported rabbit biocontrol agents, rabbit haemorrhagic disease virus (RHDV) and myxomatosis. To date, from 119 formal trapping events and RHDV-outbreak carcass-sampling trips, > 4500 rabbits have been monitored with > 8700 cELISA RHDV antibody tests and 7500 IgG, IgM and IgA RHDV antibody tests on sera (similarly for myxomatosis), and 111 RHDV-specific polymerase chain reaction (PCR) analyses run on tissue samples of the sampled rabbits. This represents an unparalleled dataset on rabbit survival, population fluctuations and disease dynamics. Read the rest of this entry »





No evidence climate change is to blame for Australian megafauna extinctions

29 01 2016

bw spear throwingLast July I wrote about a Science paper of ours demonstrating that there was a climate-change signal in the overall extinction pattern of megafauna across the Northern Hemisphere between about 50,000 and 10,000 years ago. In that case, it didn’t have anything to do with ice ages (sorry, Blue Sky Studios); rather, it was abrupt warming periods that exacerbated the extinction pulse instigated by human hunting.

Contrary to some appallingly researched media reports, we never claimed that these extinctions arose only from warming, because the evidence is more than clear that humans were the dominant drivers across North America, Europe and northern Asia; we simply demonstrated that warming periods had a role to play too.

A cursory glance at the title of this post without appreciating the complexity of how extinctions happen might lead you to think that we’re all over the shop with the role of climate change. Nothing could be farther from the truth.

Instead, we report what the evidence actually says, instead of making up stories to suit our preconceptions.

So it is with great pleasure that I report our new paper just out in Nature Communications, led by my affable French postdoc, Dr Frédérik SaltréClimate change not to blame for late Quaternary megafauna extinctions in Australia.

Of course, it was a huge collaborative effort by a crack team of ecologists, palaeontologists, geochronologists, paleo-climatologists, archaeologists and geneticists. Only by combining the efforts of this diverse and transdisciplinary team could we have hoped to achieve what we did. Read the rest of this entry »