Hippopotami have been the talk of the Trinity College Zoology department’s tea room recently. Mainly because a number of staff are about to embark on a field trip to Kenya with some undergraduate students and hippos have featured highly on the list of possible animals which an encounter with might result in death or injury, I therefore decided to investigate, partly to allay fears but mainly to stir them.
In a recent study by Dunham et al. (2010) they investigated human-wildlife conflicts which have resulted in death or injury. The fact that Hippos are one of the most dangerous animals in Africa is common knowledge (in our tea room anyway), but the good news is that crocodiles are far more dangerous. Oh and lions, lions are really dangerous, but mostly crocodiles. In Mozambique crocodiles have killed more people than all other animals combined. More good news for our would-be travellers, only 55% of hippo attacks resulted in death, whereas the figure is close to 80% for crocodiles and alarmingly even higher for elephants. Though chillingly there have been reports of Hippos abandoning herbivory for a more carnivorous lifestyle.
Overall it is good news, hippos are not in fact that dangerous as long as you can manage to keep away from the water. So our intrepid explorers can relax in their campsite in their tents on the shores of lake Naivasha just remember hippos come onto land at night to feed, so perhaps pitch your tent away from the juicy grass.
If you were given a resource that could guarantee revenue of $30 million every year, with almost triple that amount additionally coming through ancillary spending, would you ignore it? If this resource then had the power to lift some of the most marginalised people on the planet out of poverty, you would even think twice? Gorilla tourism in Rwanda is this valuable and the people living around Volcanoes National Park (one of the few remaining islands for this species) are some of the poorest in Africa. My research into interactions between the national park and local farmers has revealed that control of land is one of the key factors in creating conflict between the ideals of national park management and those of subsistence farmers. When people have little control over what they grow in this highly fertile region, either through government land use consolidation initiatives or private agro-industry, the impact of buffalos raiding potato fields or gorillas decimating eucalyptus plantations is exacerbated. The catch is, cultural values and hierarchies in Rwanda mean that leadership will be followed, as changes are effected unquestioningly. One solution is to increase the proportion of tourism revenue shared with local communities, instilling a feeling of ownership, and responsibility for, their forest. But this can only come with livelihood autonomy.
As the festive season draws upon us, Pope Benedict XVI is attracting increasing attention in the international press. Today (12th December) is scheduled to see the first tweet issued by the pontiff, a message which is predicted to reach at least 1 million followers; a remarkable number which fades in comparison to the 32 million people following Lady Gaga – what does that say about modern society?
Aside from his increasing social media presence, Pope Benedict has also been at the centre of a media storm which accused him of “banning Christmas”. The article was in response to the pontiff’s latest book, “The Infancy Narratives-Jesus of Nazareth” in which he re-evaluates evidence for aspects of the Christmas story. He commented that there was no historical record of angels singing carols and also no account of animals being present in the manger, statements which were easy fodder for attention-grabbing headlines. However, these sensationalist accounts were gross misrepresentations of what the Pope actually said and prompted a Christian news blog to release a re-assuring statement that the pontiff did not ban Christmas!
Aside from the worrying evidence of just how easily “news” can be fabricated and misconstrued, what attracted me to this story was the importance of animals in the Christmas tradition. The idea that seemed to upset people the most was the suggestion that a donkey and an ox might be removed from nativity scenes for ever more (which would undoubtedly alleviate some of the stresses associated with home-made nativity costumes!). This outcry is a reminder of our need to feel connected with animals and the natural world in general; E.O Wilson’s concept of biophilia. The presence of animals in the manger seems to be associated with some of the comforting qualities which contribute to the ever-expanding success of animal assisted therapies. Positive effects of human-animal interactions permeate all aspects of our society, from religious traditions to promoting a general sense of health and well-being in our daily lives. Some evidence even suggests that pet ownership may be correlated with longer life spans!
Rest-assured, therefore, the Pope did not in fact “ban Christmas” and both a donkey and an ox feature in the nativity scene in St. Peter’s Square. I guess this means that there will be more proud parents of “donkey number 1” swelling the audience ranks of nativity plays for many years to come!
Mr Garrison taught South Park Elementary children (season 10, episode 12) the good old fashion way of seeing evolution; “we are the retarded children of some retarded frog-fish-squirrel…”. This is the gradualist way of seeing evolutionary processes; leading from uninteresting jelly fishes to the mighty Arnold Shwarzenegger.
Many scientists reject this gradualist view in favour of Darwin’s idea that “there is no innate tendency leading to progress in evolution”. But do they really gave up this idea? A few gradualistic events in the history of life remains firmly accepted such as how the vertebrates went out of the water. . This theory refers to fossil evidence from the Late Devonian period (that’s about 350 million years ago), suggesting that early tetrapods used their legs to go out of the water and conquer the brave new terrestrial world.
However, during this last decade, many paleontologists (yes, they don’t just look for dinos) pointed out some disturbing facts: the early tetrapods, such as the iconic Ichthyostega, were in fact not able to walk out of the water at all ! So why the hell did they develop legs?
This question is an example of my favourite part of macroevolution: exaptations (when the function of a trait shifts during evolution). The French palaeontologist, S. Steyer, pointed out that early legs may have been used in many way before being useful to Usain Bolt: for swimming, for hunting (used to hold onto the seabed) or even… for sex ! S. Steyer suggested that legs could have been used to grab the female during sexy time as frogs do today.
Other interesting aspects of this gradual transition from water to land are the timing and the possible reasons why early tetrapods left the water to go conquer the new terrestrial world – which was not new at all by the way; arthropods had ventured out of the water since the early Devonian. Recent tracks discovered in Poland suggest that a 50cm long “retarded fish-frog” walked on the beach in the Early-Middle Devonian, that’s 20 million years before Mr. Ichthyostega was groping his lovely wife. Niedzwiedzki and his team interpreted these tracks (and some other “younger” ones like the Irish Valentia Island trackway) as belonging to some tetrapods that eventually went out of the sea to scavenge on the beach on low tide.
So was there really a graduale evolution from water to land in vertebrates? Who really made these tracks if it wasn’t Ichthyostega who actually just “walked ” like a walrus? Even though legs probably didn’t evolve for walking, some tetrapods may have thought that it would be fun to go on the beach for a walk and get yummy carcasses. Were their other tetrapod colleagues using their legs for less adventurous but still cool purposes such as the possibilities listed above? As an answer to these questions, let’s just say that it’s complicated and it takes more than one big step on the shore to go from the “retarded fish-frogs”…
Early ecological research relied on adventurous naturalists striking forth into unknown territory and expanding our knowledge of the natural world. This exploratory work is far from complete and many species new to science are still being identified. However, in order to study and investigate the remaining unexplored frontiers, knowing where they are is a fundamental necessity.
Finding our way around has never been so easy. GPS trackers are readily available; Google maps takes the stress out of navigating unfamiliar cities and Google Earth allows us to look down from above on some of the most remote regions of the world. The works of early cartographers with approximations of coastlines and vague “beyond here there are monsters” warnings can be relegated to historical archives. However, a recent discovery by the research vessel Southern Surveyor during its surveys of the seabed off Australia reminds us not to be so trusting of our highfalutin technology.
Sandy Island featured on weather maps and was depicted on Google Earth as lying halfway between Australia and New Caledonia. However, the 24 by 5 kilometre island was not marked on navigation charts. When the Southern Surveyor diverted its course to investigate the supposed island, they found only empty ocean with a depth of about 1.5km. Records of the phantom island seem to trace back to cartographic errors reported by the whaling ship, Velocity, in 1876. The island has now been removed from Google Maps.
From a biodiversity perspective, the non-existent island could have been home to a whole host of unusual and endemic species. The surrounding islands in this region of the South West Pacific are the remaining splinters of Australia’s separation from the ancient super-continent, Gondwana. They have high percentages of endemic species with New Caledonia recognised as one of the 25 global biodiversity hotspots. However, human colonisation of the Pacific islands caused significant biodiversity loss which continues today. If Sandy Island had existed, we can only speculate about the number of weird and wonderful creatures which, in the absence of human threats, could have called the island home.
Inaccurate maps from the 19th Century aren’t that surprising but it is pretty incredible that in our technologically savvy age an island the size of Manhattan just doesn’t exist! One expedition member commented that the mistake “raises all kinds of conspiracy theories” especially when the CIA is one of the contributing sources to the world coastline database.
I guess this is just a reminder that Google is not omnipotent after all!
During unseasonably warm, dry and bright weather in mid-October,the Global Lakes Observatory Network (GLEON) held its annual meeting in Mulranny, Co. Mayo.
The meeting was organised by TCD alumni Elvira de Eyto, Eleanor Jennings and Valerie McCarthy, along with their GLEON, Marine Institute and Dundalk IT colleagues. GLEON represents a network of scientists working on lakes with high frequency physico-chemical observations obtained from buoys deployed with sensors. It is a grassroots network of limnologists, ecologists, information technology experts, and engineers who have a common goal of building a scalable, persistent network of lake ecological observatories.
Unlike more traditional conference formats, where attendees sit and listen to research presentations, GLEON members are grouped together to discuss their areas of interest, identify potential for collaborations and to make the decisions that will inform the future path of the GLEON network. Although the program was very full, the open, collaborative and discursive approach ensured the meeting was highly enjoyable.
The current membership of this global organisation currently stands at 351, attendance at the Mulranny meeting at more than 100 and as the photo shows, there was also a strong showing of TCD students and staff, past and present.
As it is December now and the frost is creeping in I thought I’d talk about one of the all time favourite winter animals: the penguin! These happy footed, tuxedoed up cartoon-esque waddlers are among the most charismatic and endearing of creatures. They are favourites in films, books, documentaries, toys and of course a must on Christmas cards. Tales of their romantic dances, lifelong partnerships and working together to get through the winter have long been a part of the ‘nicer side’ of wildlife television and research. But are these loveable, laughable poster birds of cooperation and cuteness really all that genuine? Recent research would suggest not…
It has long been observed that emperor penguins form mass huddles to help prevent heat loss while they incubate their eggs amid Arctic storms. Anybody who has watched March of the Penguins can’t help but feel for the poor mites as they shuffle about with ice crystals covering their faces! Morgan Freeman also gives a heart warming narrative of their struggles during this time and how they “take turns” to be at the centre of these huddles so nobody is left at the edges long enough to freeze entirely. Nice thought, but it seems not quite the reality. A paper published in Plos one last week looked at the mathematics of the famous penguin huddles. What they found was that the shape and movement of these huddles over time was most accurately (although not perfectly) described by individual penguins setting out to minimize their own heat loss, rather than generously taking turns. Penguins at the edges seek to move toward the centre while those in the centre have neither the space nor inclination to move anywhere so remain stationary. The result is a dynamic huddle that actually achieves pretty uniform heat loss from the huddle. So in this case being selfish can benefit the group.
This is not the first account of penguins acting in a less than Disney-like fashion: they have been observed stealing pebbles from neighbours’ nests and waiting to see whether other, more hungry, souls fare okay in orca/seal infested waters before jumping in themselves. There are stories too of them pushing their fellows off ice floats in to swelling seas to check for leopard seals but these are largely dispelled by researchers as misconceptions of the unfortunate results of the hustle and bustle of clumsy penguins perched on cliff edges!
I’m sorry to shatter any illusions of a wholly philanthropist snuggly-for-the-sake-of-it penguin but it is another nice example of how we humans often choose to perceive interactions in the animal world based on our own ideas of moral obligation: we like to see penguins cuddling in the cold to say “see what we can face when we work together?” Don’t worry though, I am sure that none of these findings will do much to shake the penguins off of their happy-go-lucky, cuddly pedestals and they will still be a key player in the Christmas festivities and focus points of many a blockbuster documentary to come. After all, who can resist that waddle!?
Some of the most successful animals on earth live in societies characterised by a division of labour between reproducing and non-reproducing castes. One role non-reproducing members may undertake is defence. Spectacular examples include the heavily armoured termites and ants. Recently a soldier caste was discovered in an entirely new and unexpected battleground, inside the bodies of snails. The soldiers? Tiny parasitic flatworms.
Flatworms, or trematodes, have complicated life cycles, involving several different stages infecting a variety of host species. In one host, often a snail, a single trematode undergoes repeated clonal reproduction. Clones produce more clones or go on to produce the next infective stage, which leaves the snail to infect the final host. While working with trematode colonies of Himasthla sp. infecting the Californian horn snailCerithidea californica, researchers at the University California Santa Barbara observed that the trematode occurred in two distinct morphological forms. There was a large reproducing primary morph, which appeared to be the form typically described in the literature, and a secondary smaller, thinner morph.
These secondary morphs had a number of other features which set them apart. They rarely showed any signs of reproduction and were far more active. They also had huge muscular pharynxes and guts relative to their larger sisters. When researchers preformed behavioural tests, they discovered just what those large mouth parts were for. The secondary morphs attacked and killed other trematode species and unrelated conspecifics. This behaviour is not unknown in trematodes; a number of species attack and kill other trematodes. What was novel was that the smaller morphs appeared to be doing all attacking. The behaviour was rarely observed in the primary morphs. There was also a spatial segregation of morphs. Primary morphs were located in the visceral mass, mainly in the region of the gonads. The secondary morphs were more widely distributed though mainly found within the mantle. The snail mantle is the main entry point for trematodes, a strategic area to defend against invading armies. Finally, the researcher found very few intermediate morphs, suggesting that the smaller morphs were not simply juvenile stages of the primary morphs. They were a distinct, permanent caste whose function appeared to be defence – soldiers. The researchers had discovered eusociality in a completely new taxonomic group. Previously, eusocial systems consisting of morphologically distinct, specialised reproductive and non-reproductive castes had only been recognised in insects, snapping shrimp, a sea anemone and mole rats. The researchers have already suggested a further five species of trematodes that may have soldier castes.
Work from New Zealand, published this year, on another species (Philophthalmus sp.) has expanded the list of trematodes with soldier castes. The authors also showed that interspecific competition has a heavy impact on colony numbers. This is just the sort of pressure that favours adaptive strategies to reduce competition, such as a permanent soldier caste. However, competition may not be the only selective pressure driving or maintaining caste differentiation in trematodes. In the absence of competition, the presence non-reproducing morphs were found to provide a benefit to the colony, as measured by the number of infective stages produced. Precisely how this benefit comes about is not yet known. The authors suggest some form of communication or nutrient exchange may be taking place between the two morphs. This gives tantalising hints that these colonies are even more complex and interactive than previously thought.
Not only has the discovery of the eusociality in trematodes widened the taxonomic range of this phenomenon, it has also provided researchers with an exciting new tool to study its evolution. The Trematoda class contains at least 20, 000 species with a wide variety of life-histories and ecologies. The discovery is also a great example of how new and unexpected results can still come from well-studied animals. The Himasthla sp. /Californian horn snail system had been studied for over 65 years.
Humans are purpose seeking beings. Such a fact is nowhere more apparent than in our language. Some scientists argue that this tendency is a cause of confusion in their subject, especially when it comes to descriptions of evolution. The teleological turn of phrase is so tempting because of how much easier it is to read and understand than a dry purposeless, but more accurate, expression. ‘Wings evolved for flight’ isn’t quite right but we understand the message. I remember my chemistry teacher’s classes were replete with teleology, ions wanted to gain or lose electrons so they could balance their charge. But of course, none of us believed for a second that the atoms intended to do this. All there was to it were the blind forces of the atomic world. So it goes for evolution as our current understanding of the process is teleology free.
Richard Dawkins, who was put on this Earth to popularize evolution, is always quick to correct himself when his tongue slips to purpose. But I would argue that our linguistic short-cuts are not the primary cause of the public misunderstanding of evolution. It was Eugenie Scott who said for many people the problem behind evolution is not one of confusion, rather it’s a full understanding and disgust at the implications of it. Some of us don’t like the idea of being a ‘mere’ animal. Of course language matters but it would be a shame for us to avoid using language which can convey an idea so succinctly when it’s not to blame. Perhaps I’m being overly naïve here and we’re adding to the confusion with our lack of precision. So I’m open to debate on this one. What do you think?
