Standardize Job Applications Now!

I am currently 'resting', as they say in the theater, although in my case resting involves the same workload with the added requirement of filling in job applications. I probably average one a week, which is not bad given they take 2 days each to complete.

An efficiency saving of at least 10-15% could be made very easily if employers woulc agree on implementing a standard for that covers the basic data required by all application forms: name, address, email, employers, eduction, etc. Each employer could have their own layout into which the data is imported from a file, probably via XML.

Why, when such an efficiency gain can be easily made for little effort, does no such standard exist? And, indeed why does a Google search reveal no efforts to develop one?

The answer is simple - those in charge of the system (the employers) do not gain from such a system. Indeed, it may be argued that they would in fact loose out, as they would have to spend longer sifting through application forms than they do already.

So, I say to all employers and makers of electronic job application software - give the poor man a break and knock together a standard and some I/O routines PDQ. Ta.

Visualizing the Global Population Dynamics Database

The Global Population Dynamics Database (GPDD) is comprised of over 5000 long-term species abundance time series, over 270,000 spatiotemporally referenced data points in all. How can these data be visualized to explore spatiotemporal correlations between series?

The data is four dimensional: latitude, longitude, time and abundance. The geographical coordinates are all in decimal degrees so compatible across series. Series differ in temporal resolution and coverage, as well in their units of abundance.

Dates were converted to decimal years by adding the proportion of the year the observation was taken at to the year. For example, 0.04167 was added to 'January' abundances: (month number * 1/12) + 1/24.

Log abundance series were untransformed, and then all standardized (SS) by subtracting mean and dividing by the variance.

Here are two fly-by animations of these data, both done in ArcScene:

2903 european series (131,000 observations) as line-plots offset in longitude by 6 * SS (above the mean to the east, below to the west). Series are coloured by species and displayed against annual mean temperature in 1900, 1921, 1941, 1961, 1981 and 2001. This approach shows the overall distribution of series but little other pattern is revealed without interactive manipulation.

Abundance of Lynx (L. lynx , L. canadensis & L. rufus), with spheres proportional to SS. Note the pronounced and highly spatially and temporally correlated population cycles in L. canadensis compared to L. rufus.

Animating geophylogenies: fish and fire

The Trans-Mexican Volcanic Belt is a mountain range that has developed over the last 15 million years, which runs east-west across central Mexico . As the name suggests, the region is highly geologically active, with large-scale tectonic uplift, frequent volcanic eruptions, stratovolcanoes rising to over 5000m, and frequent earthquakes and faulting. This activity, combined with erosive river capture and changing rainfall, resulted in wide-spread hydrological change including the development of large lakes in the Pliocene and Pleistocene. (5.4-2.4 Mya).

15 million year or so ago the ancestor the Goodeidae freshwater fish family was caught up in this dynamic landscape as it migrated south from the southwest USA with a drying climate.The 40-odd species of Goodeidae alive today co-evolved with the hydrological landscape, which itself is the product of geological and climatic forces. Each hydrological event could split a species' range causing it to diversify into two (allopatic speciation), while in the lakes sympatric speciation involving ecological and behavioural diversification may have occurred.

I have information on species distributions and the evolutionary relationships between species, geological data and partial hydrological reconstructions. How can this information be brought together to help construct a single history from the fragmented parts?

The animation took me a couple of days to put together in ArcMap. It shows gaps (disjunctions) and marginal overlap (<50%) geophylogeny built with GeophyloBuilder for ArcGIS 1.1 from a time-scale molecular tree (Webb et al. 2004) and species records (from Dr. Constantino Marcias Garcia, UNAM). Gaps and marginally overlapping polygons are displayed from orange (disjunct) to grey (50% overlap). The node associated with each DAVA polygon and its daughter branches are shown as black dots and red arrows (pointing downstream). This biological pattern overlays some palaeo-channel, lake and watershed reconstructions (de Cserna & Alvarez 1995), and the spatiotemporal pattern of extrusive volcanics (pink; from Luca Ferrari, UNAM). The Colima graben, which the palaeolake may have drained through, is shown in purple.

The animation ends with all branches of the geophylogeny being displayed, the width of the downstream arrows being negatively proportioned to age (thin = old). The temporal scale is roughly 16 million years from start to end with the biogeographic pattern displayed by the dates from the phylogeney and the volcanics by their stratgraphic range. The temporal extent of the hydrological reconstructions has been visually set to maximise congruence with the biogeographic pattern.

What does it show? Well, disjunction and marginal overlap between the DAVA polygons indicate where a species' range may have been split in the past, resulting in speciation. The arrows point to the centroid of where the daughter clade ranges are today. Some events are congruent with change in the hydrological network and the pattern of volcanism, others remain unexplained but suggest regions where hydrological change may have occurred in the past.

References

de Cserna Z, Alvarez R. Quaternary drainage development in Central Mexico and the threat of an environmental disaster: a geological appraisal. Environ. Eng. Geosci. 1995 1: 29-34.

Webb SA, Graves JA, Marcias-Garcia C, Magurran AE, Ó Foighil D, Ritchie MG. Molecular phylogeny of the live-bearing Goodeidae (Cyprinodontiformes). Mol. Phylogenet. Evol. 2004 30: 527-544.