What You Eat Determines the Future of Our Planet

It has become so easy to live a life unaware of the impact we have on the environment, especially when it involves the food we eat. We seem to think that food consumption is a one-way deal, but how often do we question where our food comes from and what it requires to grow? Who really cares, as long as it satisfies our taste-buds and belly, right? And when you hear the words, “vegetarian” and “vegan”, images of tree-hugging personalities may come to mind. It is often assumed that these people are missing out on life or going overboard. I certainly thought so, until I woke up to another reality and became vegetarian myself, so now I can’t help wondering why society love dogs, wears cows and eats pigs. Ethics and associated health issues aside, I don’t believe one can claim to be an environmental activist without considering the impacts of their dietary choices. For example, a person may consider beef and chicken mutually interchangeable on dietary or culinary grounds, whilst the environmental cost of the production of each are not considered.

The lack of thought could be attributed to the lack of comparable information, or disparities in methodologies that afford no general comparison of relative impacts of animal-based products. However, solutions are being explored by scientists all around the world as they reveal evidence of environmental impacts of the meat, dairy and egg industries that we support.

A recent US study was published in 2014, by Eshel and his colleagues entitled, “Land, Irrigation Water, Greenhouse Gas, and Reactive Nitrogen Burdens of Meat, Eggs, and Dairy Production”.Before unpacking each concept mentioned in the title, it should be known that livestock production forms the largest use of land globally. Secondly, it must be understood that many different categories of livestock exist and the amount of feed required to sustain these animals is large. It has become difficult for sustainability scientists to quantify the environmental impacts of feed production, however it is known to broadly impact air and water quality and ocean health. Livestock-based food production also causes about 20% of global greenhouse gas emissions, and is the key land user and source of water pollution by nutrient overabundance. Land dominated by livestock farms further competes with biodiversity, and promotes species extinctions.

What motivated the study was also the need to empower consumers to make choices that mitigate some of these impacts through presenting numerically sound information – a key socio-environmental priority. The study explains the bottom-up approach in agricultural and sustainability science. This is explained as rigorous Life Cycle Assessment (LCA) methods of food production chains. Whilst earlier LCA’s investigated greenhouse gas(GHG) impacts , new methods further incorporate methods that quantify particular land, irrigation water, and nitrogen (fertiliser) impacts of feed production.

fig 1

Merging this bottom-up control with a top-down approach is a desired scenario that the study primarily aimed to achieve. The top-down approach (Fig.1) involves the environmental needs (land, irrigation water, etc.) of feed production that is divided between the different animal categories, based on the number of animals raised and the characteristic feed ration in each category. The burdens attributed to each category are then divided by the caloric or protein mass output of that animal category, yielding the final result which is the environmental burden per consumed unit(e.g., agricultural land needed per ingested kilocalorie of poultry). By introducing this methodology that allows a comparison between animal-based products Eshel and his team presents estimates of land, irrigation water, GHG, and Nitrogen (Nr) requirements of each of the five main animal-based categories in the US diet—dairy, beef, poultry, pork, and eggs—jointly providing 96% of the US animal-based calories.

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The results showed that the total requirements, including pasture land, amount to ≈40% of the total land area of the US whilst feed production requires ≈27% of the total national irrigation use. It also comprises about half the national annual fertilizer use and ≈5% of total US GHG emissions, which is equivalent to about 20% of the transportation sector emissions. Furthermore it was shown that (Fig.2) that beef production was the least resource efficient and consequently, minimizing beef consumption best mitigates the environmental costs of diet. To illustrate this, Eshel and his team found that “environmental costs per consumed calorie of dairy, poultry, pork, and eggs are mutually comparable (to within a factor of 2), but strikingly lower than the impacts of beef. Beef production requires 28, 11, 5, and 6 times more land, irrigation water, GHG, and Nr, respectively, than the average of the other livestock categories.”

Resource Consumption of Beef compared to other Categories

Resource Consumption of Beef compared to other Categories

Another fact is that US beef production has an energy conversion pathway of about fourfold less efficient than other livestock. To add to this interestingly, dairy is the most popular category, however is less efficient than pork, poultry, or eggs. I don’t know about you, but this is new to me!

So ultimately, this information offers policymakers a method for calculating some of the environmental consequences of food policies. Despite being based in the States, the study is applicable in both a regional and global context. It’s about time we start getting our facts straight and think about what we’re putting into our bodies, and what we’re taking from the environment. So the next time you’re too quick to judge a vegetarian or vegan, why not take a look at your own dietary choices? We often think individual effort is futile, but if more people practiced awareness in their dietary choices, we could collectively leverage market forces globally, for environmental betterment.

A Virtual World of Fossils

Can you imagine how dinosaurs and other extinct animals lived before humans? Can you fathom how a simple fossil can be transformed into a virtual dinosaur?pal 0

 Well, there are masterminds all around the globe working on these fascinating creatures of the past, reviving ancient biology in a computer-world. You may be familiar with the field of “Paleontology” which has its roots in the Greek language, meaning the study of ancient creatures. This study of fossil remains can assist in bridging the gaps in evolutionary records, informing us of old organisms as well as how all life-forms today came to be. Observations have existed since as early as the 5th century, however the 19th century has seen incredible documentation a of paleobiology. Research has ranged from ancient and extinct dinosaurs, to extant (still living) organisms as well as a diversity of extinct intermediate forms. Today a wide knowledge base is incorporated into paleontological studies, such as biology, geology, archaeology, chemistry, genetics,ecology and environmental information.

A cutting-edge addition can now be added to this diversity of knowledge, explained by Cunningham and his team in their June 2014 paper, “A Virtual World of Paleontology”. This study explores computer-aided visualisation of fossils and analysis of fossil records allowing specimens to be characterised in more detail. But before exploring this, it is important to understand that more often than not, fossils are found incomplete making it difficult to draw inferences from them. Extracting fossils from host rock has presented numerous challenges, with methods ranging from physical or chemical removal of the rock from the fossil or even dissolving a fossil to create a cast. The risks associated with damaging these delicate fossils are also high. In some instances of exceptional preservation, soft tissue is rarely found. Furthermore, access to fossil material often follows stringent policy apart from being physically difficult to obtain.dinosaur-dig-vacations

So it should come as no wonder why this novel technique is regarded as revolutionary. The enabling of enhanced reconstruction of specimens from incomplete fossils is a great advancement. The new digital technique makes use of “Tomography” which involves imaging by sections. A popular example of this is making sectional images through a body by using an X-ray source. Similarly, in paleobiology, it is possible to image a series of two dimensional slices through a fossil and use this to make a three dimensional reconstruction of the organism. This technique can be traced back to the early twentieth century where William Sollas began grinding through fossils embedded in rock and manually photographing sections along the way. This process of serial grinding tomography produced 2D slices which were used to recreate 3D models of specimens out of wax, polystyrene or cardboard. However this proved to be time consuming even for the best of paleontologists. One such expert, Erik Jarvik took 25 years to model a Devonian fish based on 500 detailed drawings, using the original specimen, after which had been destroyed.

Today the use of X-rays which was discovered in 1895, has become more common in digital removal of fossils. This is also a less destructive and less time consuming method. The X-ray method uses radiographs/projections of the specimen at different angles through which an X-ray beam is penetrated. The technique also utilizes scanning electron microscopes, focused ion beams (FIB), neutron tomography or laser scanning depending on the desired resolution, depth and mineral composition of the rock. The bottom line is, the resulting projections of these methods can be used to computationally generate a series of slices that can be visualised by a variety of software packages (Fig.1).

Figure 1. Fossil Mollusk

Figure 1. Fossil Mollusk (A) Photograph of ground surface of fossil (B) Digital reconstruction produced from serial grinding images

Detailed information of extinct organisms is challenging to construct, but with a rich base of anatomical information it is now possible to more easily infer functional information on organisms. The technique has become so successful that in some cases such as the ancient sarcopterygian fish, more information is known about the fossil species than its living or dead counterparts! In some cases, behavioural inferences can be made, for example, virtual endocasts of vertebrae brain cases gave insight into sensory and locomotive capabilities in extinct taxa. Development can also be studied through juvenile fossil morphologies and growth lines in mineralised adult skeletons. 3D reconstruction has also been shown to be invaluable in the understanding of fossilization processes and consequently, the probable impact of decay on modern organisms. The authors of the paper also state that “digital reconstruction involves digital restoration of skeletal data and more objective reconstruction of soft tissue anatomy which has revitalised studies of comparative musculoskeletal anatomy”(Fig.2).

Figure 2. Individual Steps in Digital Reconstruction Exemplified by a Skull Model: (A) Original fossil. (B) Digital representation of fossil. (C) Restored cranial anatomy. (D) Restored skull with reconstructed jaw adductor muscles. (E) Final finite element model based on (C) and (D)

Figure 2. Individual Steps in Digital Reconstruction Exemplified by a Skull Model: (A) Original fossil. (B) Digital representation of fossil. (C) Restored cranial anatomy. (D) Restored skull with reconstructed jaw adductor muscles. (E) Final finite element model based on (C) and (D)

In addition to this, functional analysis of fossil organisms is also possible. The engineering approach of Fine Element Analysis (FEA) can reconstruct stress, strain and deformation in digital and model fossils indicating feeding and locomotive activities of the past (Fig.3). The geometry and biomechanics of this is a bit complicated but its use gives us incredible insight into the microwear and histology of extinct organisms- and this is priceless within a hypothesis testing framework.

Figure 3. Main Steps Involved in Functional Analysis through Computational Modelling: (A) and (B) Original fossil specimens. (C) and (D) Digital reconstruction of fossils based on X-ray computed tomography. (E) and (F) Finite element meshes generated from digital reconstructions. (G) Finite element analysis of bite performance. (H) Computational fluid dynamics simulation of hydrodynamic performance

Figure 3. Main Steps Involved in Functional Analysis through Computational Modelling: (A) and (B) Original fossil specimens. (C) and (D) Digital reconstruction of fossils based on X-ray computed tomography. (E) and (F) Finite element meshes generated from digital reconstructions. (G) Finite element analysis of bite performance. (H) Computational fluid dynamics simulation of hydrodynamic performance

Digital data sets are also believed to be a likely solution to the problems of limited access to fossil specimens, however the reality of online global dissemination of this information has been rare. Consensus has not yet been reached regarding policies and legalities of data ownership, format of the information presented as well as at what stage is the findings are “complete enough” to be shared by researchers. It has been proposed that a central data repository be established, to enable access to this information. The dynamic and interactive viewing of fossil constructions would also benefit teaching institutes, and provide opportunities to assess broad-scale hypotheses relating to function, performance and character evolution of a variety of taxonomic groups.

These innovations are transforming the knowledge we have of extinct animals as well as evolution as a whole and may further unlock the potential for enhancing our understanding of the history of life.

http://www.cell.com/trends/ecology-evolution/pdf/S0169-5347%2814%2900087-1.pdf

Elephants can recognise human voices!

All animals are fascinating beings but the animal that never ceases to amaze me is the largest land mammal, the elephant. These long lived creatures are large brained and one of the most intelligent animals known. They have peakedcute_3 the interest of scientists and animal-lovers alike and their sense of alertness has shown to be astounding. They have evolved crucial cognitive skills that add to the richness of their social behavioiur, especially in their reactions to predators. Predator hunting styles and possible prey escape tactics have been widely studied in birds and mammals, but this information on elephants is not well-known. But we do know that elephants are sensitive to predators and that they turn to anti-predatory responses for safety. The most common predator of the African Elephant (Loxodanta africana) is the lion. It should not come as a surprise that humans have been identified as the second major threat to elephants, especially in farming communities. Human conflict is at the forefront of research as animal contact increases with human development.

cute-baby-elephant-5One such community is that of the Massai pastoralists who are part of the Amboseli area in Kenya. These farmers often encounter elephants as they herd their cattle to grazing and watering sites. When approached by a large grey beast, the farmers retaliate by spearing these elephants, for protection. There have been instances where elephants have attacked and killed Massai women, causing the men to go after and spear them. Naturally, tension has built up between these two species. This is unfortunate and it is a difficult task for elephants to distinguish risk magnitudes between different people.

A light at the end of the tunnel

A 2014 study by Karen McComb, a behavioural ecologist at the University of Sussex in U.K, and her colleauges investigate this conflict- where elephants have been thought to possess a sophisticated ability to tease apart different human subgroups. The study also provides the first detailed assessment on human voice discrimination by mammals!

McComb highlights that other prey animals have shown the ability to recognise visual cues from humans such as facial features, behaviour and appearance, as well as olfactory (smell) signals. Elephants are interestingly known to respond more fearfully to the scent and colour of the Massai clothing, contrary to the less harmful Kamba group of agriculturists who pose little risk and have records of low conflict. But these visual and olfactory cues are not as effective in studying these creatures as are human voice playbacks. Exploring a new territory, by use of acoustic (hearing) cues using human vocalisations, seems to be a solution!

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Other cognitively advanced species have been shown to recognize these particular voice cues which gives even more hope for this technique. Previous animal response studies have also given insight into individual human recognition, rather than specific abilities (voices) that may represent entire subgroups. But these specific abilities seem to exhibit more of a functional relevance in the natural environment. It is worthwhile as a fitness benefit to the elephants to be able to recognize different voice cues. And you will be glad to know that this ability could increase survival chances of elephants!

ellie graphThrough subtle voice characteristics of human subcategories, it was assumed that elephants possess the ability to identify potential harmful groups! This was tested as 48 elephant families in Amboseli National Park, Kenya were observed when controlled playbacks of human speech were played.

  1. The first test compared elephant responses after playbacks of Massai and Kamba men saying in their respective languages, “Look,look over there. A group of elephants is coming!”
  2. The second test compared elephant responses after Massai men and Massai women playbacks.
  3. A third test compared the responses after playbacks of Massai men and Massai boys.
  4. Lastly re-synthesized versions of the male and female playbacks were used to mimic sex differences in the Massai. This means that subtle tones in the original female playback were changed to make it sound like a male’s voice, and vice versa- to really discover what cues were being sensed by the elephants.

And some staggering results were found!

  1. Investigative smelling and defensive bunching when Massai calls were heard, but not with Kamba
  2. Retreating and investigative smelling and bunching in response to male (but not female) playbacks
  3. Subtle distinctions could be made between older and younger male voices- more fearful responses were found after older male playbacks
  4. When male voices were re-synthesized, even though they had the frequency of female voices, the elephants still responded more fearfully to these altered (originally) male voices.

Perhaps the altered male voices were perceived as younger (herder) male voices? A residual acoustic indicator seemed to be lurking- something humans cannot differentiate. So it seems like the elephants have a much more subtle way of distinguishing different voices, far more than we can perceive! This is truly amazing and has shown that language and sex cues can very well be used to assess predatory threat . Whether this is a skill learned during developmental stages or acquired from older elephants, there is no doubt about the intelligence of these magnificent mammals. “Animals associating sounds with danger is nothing new — but making these fine distinctions in human voices is quite remarkable,” said Frans de Waal, from Emory University.baby-elephant-hug-big

The co-evolution of humans and these cognitively advanced mammals is surely an exciting step in the world of science, allowing the exploration of this fascinating paradigm!

http://www.pnas.org/content/early/2014/03/05/1321543111