Curiosity lands on Mars

Weird and Wonderful: Death’s Head Hawk Moth

Gemma Hallam

Death’s Head Hawk Moth

No it’s not from Star Wars or Dr Who, but it did hold a starring role in The Silence of the Lambs! It’s the largest moth to be found in Britain, measuring up to 13cm fully grown. The Death’s Head Hawk Moth comes from Tropical Africa, but spends time during late-Summer migrating to tepid areas of Europe, Northern Ireland as well as southern and eastern England.

These poor fellows have become an omen of death as they have a skull-like marking on their ‘chest’ between their head and abdomen.  The 3 species of Death’s Head Hawk Moths all have sinister names; Atropos – a member of the moiari who cuts the thread of life in Greek mythology, Lachesis – another of the 3 moirai, responsible for deciding the length of a person’s life thread, and Styx – the river to the underworld. The third moirai, Clotho, may have missed out on the allocation of one of the species, because her role in the trio is deciding when people are born and she can bring people back from the dead; far too optimistic for association with these gloomy moths!

The caterpillar comes in 3 coloured varieties: a light green/yellow with darker stripes (as pictured), a pale blue shade with washed-out stripes, and a brown snakeskin type with a white head, which makes it look like a bird poo! They do not hatch from their larva with the stripes, but develop them at the 3^rd out of 5 stages (or instar) of being a larva (before they become a caterpillar). They’re not very active and only move to feed (sound familiar?), but they are feisty! If disturbed, they thrash about in an attempt to gnash their attacker with their mandibles.

The insects have relatively short proboscis (protruding tubular noses used for feeding) rendering it incapable of reaching into plants to feed on the nectar. Instead, they feed on honey, tricking the bees into not attacking them by squeaking in a way similar to the Queen Bee. If a guard bee attacks them, it’s not too much of a problem because with their immunity to the bee sting and thick, protective bodies, they can handle a bit of hassle, however, after drinking honey, the moths can’t squeak for about 5 hours and have to make a swift exit from the hive. They’re aided in doing so through ‘chemical camouflage’, emitting an odour containing the 4 fatty acids that bees carry around. This has earned the species the nickname ‘bee robbers’, but they will settle for rotting fruit and tree sap. The larva feed on potato leaves (although this has decreased with the rise of mechanical farming), buddleia and ominously, deadly night shade.

Death’s Head Hawk Moth caterpillar - James Twose

Although there’s all this negativity related to the Death’s Head Hawk Moth, you can’t help but admit they’re striking fellows. They have dramatic black and yellow stripy hindwings (they have 2 pairs of wings) and abdomens. Their pupae are a lovely deep mahogany and shiny, although thinking on it, they may also look a bit like a poo. My sympathy is with them!

Check out this video about the Death’s Head Hawk Moth:

Explore the Universe

Weird and Wonderful: Glaucus atlanticus, the real life Pokémon

Tom Stubbs

This peculiar creature has only recently become famous and many people have still not even heard of it. The most amazing feature of this animal is its stunning appearance, looking like a cross between a dragon and a Pokémon! In fact Glaucus atlanticus is a sea slug, in the group Gastropoda, that also includes snails and land slugs. G.atlanticus is actually rather small reaching a maximum size of around 3cm. Despite its small size this miniature dragon mimic has many amazing characteristics. They use gas bubbles in their stomachs to float in the water column and pursue prey using appendages to swim. Amazingly G.atlanticus feeds on hydrozoans, including the infamous deadly Portuguese Man O’ War. They have the ability to harness poison from the stings of prey and use this as a defensive sting themselves, which unlike most sea slugs, can hurt humans. Finally, G.atlanticus is also a hermaphrodite possessing the reproductive organs of both sexes!

Spread the word about this amazing little critter and check out the video below:

Evolution of the athlete

Felicity Russell

As the London 2012 Olympics draw to a close and we have watched how our athletes push their bodies to the extreme to achieve award winning performances, it is easy to see what an amazing species we are. A species more advanced compared to the many other living creatures that we share our planet with. Especially as our closest living relative happens to be the chimpanzee, that split from us 6-8 million years ago. How is it that tree dwelling apes evolved into a species capable of such athleticism? Only recently numerous fragmentary fossils have been discovered which start to reveal our origins and how we came to evolve.

Sahelanthropus

The oldest suspected hominin species found is Sahelanthropus, thought to be 6-7 million years old. The skull appears ape-like but has a distinctive browridge like other identified hominin species. The hole at the base of the skull where the spinal cord passes (foramen magnum) is horizontally orientated suggesting a bipedal posture. Another indication of a hominin species is provided by the shape of its teeth, Sahelanthropus has small canines unlike the larger sharp ape-like canines. Ardipithecus ramidus and Ardipithecus kadabba, thought to have lived between 5.8-4.3 million years ago, are two more examples of hominins where tooth shape indicates a more human like function. However, clues found from Ardipithecus toe bones controversially suggests bipedalism, as joint surfaces are different in humans whose feet flex up to a greater extent than chimpanzees.

Australopithecus species, such as Australopithecus afarensis, Australopithecus anamensis and Australopithecus africanus, lived approximately 3 million years ago. They have thicker tooth enamel compared to apes and the shape of their canines and premolars suggest a more human function. The presence of shorter, broader hips is indicative of a more human like posture and leg bones have revealed human like features. The Paranthropus group, often thought as part of the Australopithecus group, existed 2.5 million years ago. They are also described as bipedal and interesting dental evidence suggests they were especially well adapted to eating nuts and seeds.

Early Homos, such as Homo habilis, Homo rudolfensis and Homo erectus are thought to have lived within the last 2.5 million years, coincident with discoveries of stone tools. A bigger brain size has often been associated with early Homos, suggesting they are more like Homo sapiens (‘intelligent man’). Three new fossils have recently been discovered supporting claims that Homo rudolfensis is a separate species from Homo habilis. Later Homos include Homo heidelbergensis, Homo neanderthalensis and Homo floresiensis. Homo heidelbergensis lived 300,000 to 700,000 years ago and wooden spears have been found nearby indicating that they hunted large animals. Homo neanderthalensis are thought to have used more advanced stone tools to carve meat from larger mammals. They had a large browridge and a human-sized brain. They are also known to have buried their dead and the more recent Neanderthals also made simple jewellery from animal teeth. They may have gone extinct as recent as 30,000 years ago. Homo floresiensis is the most recent distinct species, living up to just 17,000 years ago. They were short, often referred to as hobbits, and despite having smaller brains researchers have still found evidence that this species also used tools. Homo sapiens may have existed as long as 200,000 years ago originating from Africa and by 30,000 years ago they replaced Neanderthals in Europe.

Did humans evolve to run? ILLUSTRATION BY PHIL DISLEY

Noakes and Spedding (2012) have now suggested that it is our ability to run and to dissipate heat which aided our evolution. As forests disappeared and large open savannahs appeared, our ancestors had to adapt and evolve from a skeleton developed for tree climbing to a structure required for walking and even running. A lack of body hair and the ability to sweat as much as 3 litres in an hour meant we could lose heat more easily and enabled us to chase after four legged prey which require panting as a mechanism to dissipate heat. The prey would not be able to pant and run at the same time and eventually would be driven to heat stroke. The development of longer legs, shorter toes, a stronger gluteus maximus, larger weight bearing joints and broader shoulders is suggested to have aided our ability to run long distances. We have also been able to develop an aerobic capacity capable of supporting such long distance runs unlike any other ape species. Therefore as you celebrate how extraordinarily well our athletes have done for London 2012, remember how remarkable evolution can really be.

Fun point: Australopithecus anamensis, Australopithecus afarensis, Australopithecus africanus – try saying this over and over again it is definitely a tongue twister. 

The evolution of human stance

More information:

Fossil record of early humans - http://www.becominghuman.org/node/human-lineage-through-time

New fossil discoveries - http://www.newscientist.com/article/dn22151-fossils-confirm-three-early-humans-roamed-africa.html

Noakes and Spedding (2012) paper - http://www.nature.com/nature/journal/v487/n7407/full/487295a.html?WT.ec_id=NATURE-20120719

The Animal Olympics

Tom Stubbs

We are over halfway through the Summer Olympic Games of 2012. Over the last week we have witnessed some incredible feats of speed and strength and multiple world records have been broken. But how do us hairless bipeds compare to other members of the animal kingdom?

Speed kings
Usain Bolt won the 100m sprint gold medal with a time of 9.63 seconds and in the 2008 Beijing Games he ran 9.69 seconds to win gold. More impressively, in the 2009 World Championships Bolt set two world records, running 100m in 9.58 seconds and 200m in a time of 19.19 seconds. This consistency has established him as the fastest human athlete ever. However, compared to some members of the animal kingdom Bolt looks like a bit of a slouch. The cheetah could complete the 100m sprint in 5.8 seconds and it is around twice as fast as the world's top sprinters, reaching speeds of 64mph. Bolt’s 200m record would be smashed by a cheetah that would complete it in just 6.9 seconds. The pronghorn antelope is another speedy competitor with running speeds of around 55 mph. If the pronghorn entered the 800m it could complete it in an incredible 33 seconds. To put this into context, the Kenyan 800m world record holder, runner David Rushida, ran that distance in 1 minute, 41 seconds.

Stamina, strength and swimming
How do our athletes compare in other Olympic events? Well this year’s Olympic gold long jump was won by Greg Rutherford with a leap of 8.31m. The world record long jump is a whopping 8.95 meters, currently held by Mike Powell. This distance approaches the leap of the red kangaroo (12.8 m) but falls short of the snow leopard that can jump up to 15 metres. Behdad Salimikordasiabi is considered the strongest man in the world after winning gold in the men's +105kg weightlifting category, lifting 247kg in the final. An elephant can lift 300kg with its trunk alone and the Gorilla, one of our closest relatives, can lift an unbelievable 900kg! It would be hard to argue that Michael Phelps is not the greatest swimmer of all time. In a 200m freestyle race Phelps swims around 4mph, a sailfish can travel at speeds of 67mph!


Although these comparisons may seem rather strange because the various animals mentioned are adapted to a specific mode of life, it does serve to highlight the incredible athletics abilities evolved through natural selection. Equally, these comparisons highlight the exceptional versatility of the human body. With training, athletes are able to tune their bodies to specific tasks. Can you image finding individuals within any other species that have such variation in speed and strength? This is what the Olympics places in the spotlight.

Check out the videos below!

Bolt vs. Cheetah 

  

The 10 Fastest Creatures on Earth

Ants, Bees and Brains

Alicja Jedrzejewska

Ants, bees and brains, or more specifically rock ants, honeybees and neurones, have surprisingly a lot in common. However insignificant when singled out, when grouped together as a swarm, colony or a brain, they can generate astonishing properties. Are the properties of these superorganisms enough to conclude they can think as one, just like the brain? In other words, is there colony-level cognition?

An example of such an emergent property is colony-level decision making exhibited by ants during house hunting. The scout ants visit potential house sites. They collect information about the site, including the size of the cavity, the width of the entrance and the darkness.  If a scout ant evaluates the house to be appropriate, it starts teaching other ants the way to the new house, so they can also evaluate it. This is done by secretion of chemicals called pheromones along the path to the house. The other ants can smell these chemicals, which allow them to trace the correct way. This behaviour is known as tandem running, and enables other ants to visit the site and decide for themselves whether they think it is a good site or not. If a nest is of good quality, a scout will wait less time before recruiting others to it, whereas if it is of poor quality they will wait a lot longer. This period of waiting is the latency period.

House hunting ants

When enough ants are present in the new nest a quorum is reached, and the whole colony makes a decision to move. This is a rapid move whereby ants start carrying other ants on their backs to speed up the process. The quorum threshold depends on individual situations. In times of danger speed is more important than accuracy so the quorum threshold decreases drastically (less ants have to be present in the nest in order for a decision to be reached), whereas when the colony is safe the quorum threshold rises so a more accurate decision can be made.

Just like ants, bees reach the decision of moving their hive collectively. Individual bees go out looking for new hives. When they encounter an appropriate site they do a waggle dance in front of the other bees. The waggle dance informs the other bees about the location of the site. This allows the other bees to investigate the site by themselves. The better the site the longer the bees will dance for. With time more and more bees start to dance advocating their ‘favourite site’. When there is a close match between two sites bees start to ‘buzz’ one another in an attempt to silence the bees advocating the competing site. This allows for a collective, final decision to be made.

Just like ants and bees, neurons ‘make’ decisions collectively. An example of this can be seen when a person is presented with a screen with some dots going right and some left and a decision has to be made as to where most dots are going. Some neurones will be firing due to left dot movement and others due to right movement. Final decision is based upon the larger number of neurones firing for either side.

So there you go! Ants, bees and brains have more in common than you originally might have thought. A lot of research in this area is still going on and we are learning more and more about the fascinating properties of colony-level cognition. Some of the pioneering research in this field is actually being carried out by researches at the University of Bristol. If you would like to know more about the information in this article let us know via email or otherwise, and we will provide you with the references used to write it.

More information:

Waggle Dance of the Honeybee - http://www.youtube.com/watch?v=bFDGPgXtK-U

The science behind Spiderman

Tom Stubbs

Superheroes have amazed audiences for almost 80 years. They showcase a spectacular range of supernatural abilities; but are any of these possible? The video below examines the abilities of Spiderman. Could a retrovirus cause immediate cell mutation? Can spider-size physics be scaled to a human? Is there such a thing as 'spider-sense'? Find the answers in the video below and share with your friends.

Video from ASAP Science - http://www.youtube.com/user/AsapSCIENCE

The controversy of immortal cells

Louisa Cockbill

Did you know that it is possible for human cells to be removed from the body and survive, even multiply in number? Growing cells outside the body is known as ‘cell culture’. Cells grown in culture are often taken from tumours because tumour cells have the ability to grow infinitely when supplied with nutrients.These immortal cells are incredibly important in medical research, as they allow researchers to study and experiment on cells humanely; that is outside the body.

HeLa cells

But where do these cells originate from? I mentioned that many cells in culture are originally taken from human tumours, from biopsies or from a surgically removed tumour. Nowadays ethical permission is received from the patient to study the tumour; however medical permission forms didn’t always exist and neither did cell culture, so where did the practice of growing cells come from?

The first cells ever to be immortalised in culture were from a biopsy of a cervical mass (a tumour) from an African American woman called Henrietta Lacks from Baltimore in 1951. They were called HeLa cells and their immortalisation in culture changed the face of medical research. HeLa cells were exposed to all forms of bacteria and viruses to study the method of infection, replication etc. in order to block these processes with antibiotics, vaccines etc. Indeed Polio vaccine neutralisation tests were some of the first vaccine trials that used HeLa cells. Today HeLa cells can still be found cultured in every lab and it is estimated that 50 million tons of HeLa cells could have been grown.

I’ve always viewed cell culture from a purely scientific perspective, but since reading ‘The immortal life of Henrietta Lacks’ by Rebecca Skloot I’ve started to look at cell culture from an entirely new perspective. Henrietta Lacks’ family didn’t find out about her immortal cells until 1973; 22 years after HeLa cells were first cultured. Why had no one told the family? Why is it that the Lacks family can’t afford health insurance, when their mother’s cells have driven forward frontiers in understanding disease?

The truth is that Henrietta’s cells were cultured without her knowledge or consent at a time before regulations were set in place to safeguard patient’s rights. Regulations now ensure that informed consent must be received and the patient informed of any commercial benefit that can be made from their medical donation.

Henrietta Lacks

I think what particularly struck me on reading ‘The immortal life of Henrietta Lacks’ is how strange it must have been for Henrietta Lacks’ children to find that cells from their mother were alive! It has made me wonder how I would feel if cells had been taken from my Grandmother’s colorectal tumours and grown; who knows, she died in 1965 before law ensured patient consent, maybe her cells are out there. It’s a disconcerting thought.

On the other hand how amazing would it be if the cells from the cancer that killed my grandmother were used to cure the disease? Especially handy as the cancer appears to be hereditary. Indeed although the Lacks’ family are indignant at not being informed about the culture of HeLa cells for two decades and the lack of explanation given them, they are marvelled by the medical breakthroughs made possible by the cells cultured from their mother.

The story of Henrietta Lacks may have made me question certain scientific precepts but has certainly opened my eyes to better appreciate the invention of cell culture and the lives behind the cells. To read more about Rebecca Skloot’s discovery of the world of Henrietta Lacks and cell culture I’d advise you to read ‘The Immortal life of Henrietta Lacks’ which is available for loan from the University of Bristol Medical Library.

More information:

http://henriettalacksfoundation.org/

http://www.youtube.com/watch?v=_FaQ9Utx--E

Glorious gas giant

Tom Stubbs

This spectacular photo shows Saturn’s legendary rings and two of its moons. The photo was snapped by NASA's Cassini spacecraft as it orbited the gas giant. It allows scientists to get up-close and examine the shifting motions and intricacies of Saturn's rings. The Cassini spacecraft arrived at Saturn in 2004, it recently changed orbit gaining this new perspective. Saturn is currently shining bright in the night sky so see if you can spot it.

For more information on the Cassini mission:

NASA - http://saturn.jpl.nasa.gov/photos/

Nature’s greatest illusionists

Tom Stubbs

Camouflage is one of nature’s greatest inventions. It is a mode of concealment that allows animals to remain unnoticed and blend into their environment, increasing the animal’s chances of survival. There are many common examples of camouflage, including leopard's spots and zebra's stripes. Mechanisms that increase survival and reproductive rates are strongly selected for by natural selection, this has led to the evolution of some amazing methods of camouflage that you may be less familiar with. Here we explore just a few exceptional animals that are masters of deception.

The Dead Leaf Mantis 

Dead-Leaf mimics

The Dead Leaf Mantis (Deroplatys desiccata) is a large mantis found in Malaysia. If you haven’t guessed already, it is camouflaged as a dead leaf. It achieves this using a large shield on its back, the prothorax, that is covered with a variety of colours and spots. When threatened they lie motionless in the leaf litter. This is an excellent example of crypsis. Believe it or not many people keep this species as a pet, check out the video at the bottom. While we are on the topic of dead leaves, there is also the Dead-Leaf Butterfly (Kallima inachus). It has a diet of plants and rotting fruit so it spends a great deal of time resting within the leaf litter of tropical forests. Depending on the environmental conditions the butterfly can mimic variable degrees of decay.

Orchid Mimic Mantis 

Orchid mimics
If you prefer your plants alive, then there is also the beautiful orchid mimic mantis (Hymenopus coronatus). This incredible animal uses legs that resemble flower petals to remain hidden on orchids. They can be found in rainforests of Sumatra, Indonesia and Malaysia. Many varieties of such orchid mimics are white, but some are wonderfully colourful. They are carnivorous so as well as helping them to avoid trouble this camouflage also helps the mantis capture a wide range of flying insects and small lizards. It also has the ability to change colours on a daily basis.

Sea dragons
Amazing examples of camouflage are not just found in creepy crawlies and are not just on land. There is also the Leafy Sea Dragon (Phycodurus eques).This animal is a fish belonging to the family including sea horses. It is one of the most ornamented camouflaged creatures on the planet. They possess large bodies and leaf-like appendages over their entire body, allowing them to blend in with seaweed and kelp formations. The leaves are for camouflage only and don’t help with movement. Sea dragons are endemic to the oceans of south and east Australia and feed upon tiny crustaceans such as sea lice. Again their beauty has made them popular pets and they are taken from the wild illegally.

Leafy Sea Dragon

Leaf-tailed gecko 

Leaf-tailed gecko

Reptiles have also mastered the art of disguise. The leaf-tailed gecko (Uroplatus sikorae) is one of the best examples of this. The critter is found only in the tropical forests of Madagascar and a few nearby landmasses. They have evolved moss and bark coloured scales in addition to dermal flaps that disrupt their outline. When they lay flat this cryptic colouration makes them perfectly match the branches of tropical trees when basking during the day. Like chameleons, these reptiles can also modify their colouration according to their surroundings.

More information and great videos - 

Dead-Leaf mimics - http://www.youtube.com/watch?v=9XrXRRR4WJk

Orchid mimics - http://www.youtube.com/watch?v=wygk67ZHxCA

Sea dragons - http://www.bbc.co.uk/nature/life/Leafy_sea_dragon#p003jx7z

Image credits - http://www.flickr.com/photos/feuilllu/ and http://www.flickr.com/photos/leemt2/

Dangerous Results: To Publish or Not To Publish?

Gunnar De Winter

So you thought the avian flu controversy was over? Far from it. A little while ago, two studies on the avian flu H5N1 sparked some controversy. Both studies detailed how the researchers were able to produce a flu strain that, in contrast to the known natural strains, would be highly transmissible between human beings. This research has potentially dangerous consequences. Debate ensued. Should these studies be fully or partially published, or not at all? Both the National Security Advisory Board for Biosecurity (NSABB) and the World Health Organization (WHO) issued press releases describing their (different) recommendations. Editors of Nature and Science postponed publishing the respective studies. But this is part of a wider issue: should studies with potentially dangerous results be published or not? Let’s look at some options.

Don’t Publish

Simply don’t publish the studies. Problem solved. Or not? This is the least popular ‘solution’ for the problem. An even more extreme version of this option is to simply not allow research that might yield dangerous results. But luckily almost nobody seriously considers this. After all, one can’t predict potential applications of research. And besides potential misuse, there might be great benefits as well (such as vaccine development in the case of the avian flu studies). Moreover, freedom of research is at stake here. If all research that might be abused by others is suspended, surely the scientific enterprise will wither until almost nothing remains. So, this option provides no solution. Moving on, then.

Publish Partially

Avian influenza A H5N1 viruses

Publish the studies, but leave out some key methodological details (which was the NSABB recommendation for the flu studies). Intuitively, this appears to make (some) sense. But there are problems here as well. First, who decides what to leave out? Furthermore, if other researchers want to build upon the results, they should be able to acquire the omitted details. But at the moment, there is no system to properly coordinate this. Finally, some people point out that just knowing that it’s possible is enough for others to figure it out. It might take a bit longer, but they’ll get there. Well, it seems option two also has its problems. On to the final option.

Publish Completely

Just publish the studies in full (the WHO recommendation). Most scientific research comes with a risk of potential misuse. This, however, should not stop enquiry. Besides, the best protection against abuse, so some argue, is to spread knowledge about whatever is being researched. In case of the flu studies, publishing the studies in their entirety is the best chance of finding a vaccine, thereby counteracting possible abuse. Scientific research in itself is not good or bad. It’s how it is used by people, or by society. The solution therefore is not to curb research, but to promote ethically and morally sound use of scientific knowledge. Achieving this, of course, is not an easy task, and there are many questions to be addressed, but it seems to be the best option we’ve got…

For more information about the avian flu debate:

Nature’s Mutant Flu News Special (http://www.nature.com/news/specials/mutantflu/index.html), where the latest news concerning the studies and several opinion pieces are aggregated.

A similar news and commentary collection can be found on Science’s Public Health, Biosecurity and H5N1 feature (http://www.sciencemag.org/site/feature/data/hottopics/biosecurity/index.xhtml). 

Why do our fingers wrinkle when wet?

Gemma Hallam

Look familiar?

Now you’re home from student accommodation you may have re-established access to a bathtub! And there’s nothing better than a steamy, relaxing wallow to cheer us up from this ghastly downpour, which is invading our ‘summer’ break. But upon finally emerging, you look down at your hands and feet and wonder at what point your appendages were replaced with those of an old lady!

Layers of the skin

What happens is the outer layer of skin (the epidermis) absorbs a little bit of water and expands. The layer underneath (the dermis) doesn't do this and so the skin on top buckles – folding in places – leading to the wrinkly digits we’re all so familiar with. The skin on our hands and feet is thicker than on the rest of the body and so the changes here are noticeable whereas the rest of our braised bods appear to have remained less than 80 years old!

'Wrinkle drainage'

Another idea was recently forwarded that suggested ‘pruney’ fingers are an adaptation to help humans and other primates grip in wet conditions. In this theory the wrinkles act like rain treads on tyres allowing water to drain through channels when we press our fingertips on a wet surface.

Functional or unintentional it is certainly a relief when our hands dry and return to normal!

For more information on the current theories check out this link - Are Wet-Induced Wrinkled Fingers Primate Rain Treads?

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