Water, water, everywhere...

It takes over 17,000 litres of water to produce just 1 kg of chocolate.

That's one of the startling figures compiled in a new report on food waste by the Institution of Mechanical Engineers in the UK.

The report: Global Food - Waste Not, Want Not; made the news last month because of the headline-grabbing figure of 50%. That's the proportion of food wasted worldwide without ever reaching a human stomach.

The figures for water usage in the report come from the Water Footprint Network and make for stark reading when tabulated (see below). For example, it takes 822 litres of water to produce 1 kg of apples.

On average, 1 kg of beef takes 15,415 litres of water to produce and one cup of tea takes 27 litres.

The various wasted inputs (water, energy, agrochemicals, etc.) associated with wasted food is often not considered by consumers but, as the report states: "[the 50% headline figure] does not reflect the fact that large amounts of land, energy, fertilisers and water have also been lost in the production of foodstuffs which simply end up as waste".

Water use in agriculture (Source: Global Food - Waste Not, Want Not)

According to a recent European Environment Agency (EEA) report on water use in Europe, agriculture accounts for 33% of total water use. That figure can go as far as 80% in parts of southern Europe where irrigation of crops is essential and accounts for almost all agricultural water use.

In the clamour for higher yielding varieties of crop plants for agriculture, it makes sense to stop and think about how current yields are squandered and how limiting resources such as water and energy and thrown in the bin.

You can read the food waste report here.

You can read the EEA report here.

I write more on the issue of food waste, the global future of crop production and precision agriculture in the Spring edition of Walton Magazine, which is out now.

Image: Watering Crops by Margaret W. Nea. Creative Commons

Why the Irish Potato Famine was not caused by a fungus

During the long, wet summer of 2012 (perfect late blight weather!), I gave a short public talk about the potato and late blight as part of the Taste of West Cork Festival in Skibbereen, Co. Cork.

The panel of speakers also included the excellent and informative broadcaster Éanna ní Lamhna (of RTE radio fame) who spoke about the history of the potato as well as the history of the Irish potato famine.

Despite the argument that political and economic issues had a great role to play in the Irish potato famine, there is no doubt that the loss of the potato crop due to late blight was the trigger that started it all.

Late blight was, and is, caused by the plant-pathogenic organism Phytophthora infestans which, unfortunately, many people describe as a 'fungus'.

Éanna ní Lamhna described it as such during her talk and I, humorously and good-naturedly (I think!), pulled her up on it. As you can imagine, given that much of the audience had come to see and hear the delightful Ms. ní Lamhna and not some young upstart like me, I had to thread very carefully and there was much friendly banter.

Speakers at the 'Humble Spud' talk

You can't blame anyone for making the mistake - P. infestans is often described as a fungus by those who really should no better.

Browsing through the excellent Atlas of the Great Irish Famine (Cork University Press) recently, I noticed the disease-causing organism is described in several places therein as a 'fungus'.

In a news report in a January issue of the journal Nature, P. infestans was described as "an organism similar to, and often grouped with, fungi". If the author meant that it is often grouped or lumped-in with fungi on a casual (and incorrect!) basis, she's quite right, but as we now know, the organism is not grouped (i.e. classified) as a fungus by fungal taxonomists.

The minutiae of fungal taxonomy is not something we should get bogged down in here (although some would argue that that boat has sailed!), but P. infestans is classified as an oomycete and can be found in the same kingdom as the brown algae and diatoms. Although it may have started out in the Fungi kingdom, it is now firmly categorised as a 'fungal-like organism'.

Damage caused by late blight of potato (APSNET)

A letter in this week's issue of Nature, taking issue with the original news report, states: "It was Anton de Bary, the father of mycology, who coined the genus name Phytophthora ('plant-destroyer') and classed the pathogen as a fungus. But modern molecular sequencing indicates that his interpretation was incorrect"

"The organism is actually an oomycete, a pseudo-fungus that evolved from killer ancestors in the ancient oceans and not from wood-degrading fungi", concluded the author.

Within mycology (the study of fungi), there is some debate over the use of the term fungus. While none would argue against the weight of molecular evidence that clearly puts P. infestans outside the Kingdon, some would argue that, since they are of interest to mycologists and they share many of the common morphological features of fungi, a broader defintion of the term is required.

Money (1998) has argued that the term fungus should have two distinct meanings: (1) the strict taxonomic name used to describe organisms from the Kingdom Fungi and (2) a practical reference to organisms studied by mycologists that share similar characteristics to fungi.

Somehow, I think the taxonomists would disapprove, and so would I.

What would the first mammal look like?

The image below might look like your average small rodent - long tail, sharp teeth for insect-eating and small enough to fit in the palm of your hand, it is in fact, what scientists predict the world's first mammal looked like.

An artist’s rendering of the hypothetical placental ancestor (by Carl Buell)

About 65 million years ago, some 70% of the species on the planet were wiped out by some cataclismic event. After this wipeout, a new group of animals emerged which were to evolve to be the most successful on the planet.

The placental mammals vary hugely in size and shape. Of the c. 5,100 species now extant on earth, they range from the bumblebee bat that weighs around 1.5 g (that's just half the weight of a 2 cent (euro) coin!) to the blue whale that weighs in at 190,000 kg.

Now, scientists from around the world have published (pdf) what they believe the first of these mammals looked like. Using a mixture of genetic and morphological data, the team deduced that the "hypothetical placental ancestor" weighed between 6 and 245 g, ate insects and produced single offspring which were born hairless with their eyes closed.

The paper concludes that the placental mammals arose quickly after that cataclismic extinction event, known to scientists as the Cretaceous-Paleogene (K-Pg) event, probably between 200,000 and 400,000 years afterwards.