Greetings everybody,

TGIF! It has been one of those weeks for me guys. It is officially exam season for mock GCSE's, real GCSE's and A-levels meaning that as a tutor I am a very busy bee! Its okay though because it is my favourite day- its blog day. I have an interesting one for you guys today. We are going to take a look at Mother Natures dark side, those hidden secrets not seen in nature documentaries often. Enjoy.

Golden poison-dart frog: 

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What a golden cutie! Meet the frog that produces the most deadliest poison of any recorded animal. This deadly poison is located on the skin of the frog. In the case of our golden poison-dart frog, size does not matter. These frogs are around 5.5 cm long and have enough poison to kill 10 grown men.

The toxins specific name is Batrachotoxin. Once inside the body it causes severe irreversible damage to an animals brain and muscles. This commonly leads to high blood pressure, seizures, respiratory paralysis and finally death. Even when exposure to this toxin is minimal! 

Deadly dynamic duos:

It may be safe to assume that we all look at larvae and think 'gross'. Perhaps after learning about their slow and horrible death we can all feel a sympathy for them. 

It all starts with a nematode (a type of ringworm) on the lookout for its next victim. A grub or larvae. Once located the nematode invades the larva through its breathing hole or by using its tooth to burrow inside. As it reaches the inside of the larvae it sets loose an army of bacteria from its own gut. These bacteria begin to produce toxins, digestive enzymes and even antibiotics! 

The image below, shows a larvae that appears to be glowing.This light show is down to the presence of luminescent bacteria inside the grub, slowly digesting it from the inside out! There you have it the glow of inevitable death.   Lastly, (as if this life cycle was not weird enough already) the nematodes then consume both the bacteria and the corpses remains! These two then go on elsewhere to do it all over again. 

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This is a perfect, yet grim example of interdependent parasitic partnerships. The nematode provides the transport link between one meal and the next. The bacteria in the gut are needed to aid in the digestion of the meal. A mutual partnership built on the cruel death of grub and larvae. 

The butcher bird: 

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Commonly known as the Grey Shrike, and seen in Britain in various seasons. For the birdwatcher inside you, it is easy to find where these birds rest, all you have to look for is a series of impaled victims on either a horned tree or barbed wire! The latin for this beautiful bird is Lanius excubitor meaning the butcher sentinel. This provides a subtle hint into the bird predatory nature of the bird.  

This little bird will be seen perching itself on high vantage points. Prey items for this butchering bird are small mammals birds and the occasional lizard. Once captured, the prey are carried to a thorned tree or barbed wire and then... impale it. Once skewered, the shrike with tear it to pieces with its razor sharp beak. Any remains are left as little horror decorations.

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If you thought this bird could not get any scarier or deceptive- your wrong. Grey Shrikes have picked up the ability to mimic their preys calls. I know! How devious. Shrikes lure their prey in by mimicking their calls and then... they pounce.

The assassin bugs: 

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Clue is in the name, these are pretty badass bugs. Assassin bugs impale their victims by spearing them with their needle-like mouthparts. Once speared the victims body is filled with paralytics and digestive juices. Paralytics stop the prey from escaping, whereas the digestive juices do the job of liquifying the organs and turning them into a high protein slushy. This is then sucked up by the bug! Eww

Acanthaspis petax, has an extremely special ritual for their kills. Their favourite prey item are ants. This assassin bug makes its armour out of the dead bodies of ants! Pretty extreme. 

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Feather legged assassin bugs, produce an irresistible substance to lure ants to them. When the ants lick this secretion they become paralysed. Doomed to their fate. The assassin pierces the ants cavity and sucks up all bodily organs. Lovely. 

The Dementorwasp: 

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I know what you're thinking. This cannot possibly be real? But it is. This particular species gained its name through a public vote. A publicity stunt to get the public more engaged with classification and biodiversity. After learning about the predatory behaviours of this little wasp, Dementorwasp was chosen. 

Like all wasps, they carry a sting. Dementorwasps use theirs to inject a cocktail of neurotoxins directly into the brain of a cockroach. Once injected the neurotoxins get straight to work, by enslaving the roach to the wasps will. 

In its docile state the roach is lead to the wasps nursery. Once settled in nicely the wasp lays her eggs on the inside of the roach. The inside of a roach may seem like an awful place to lay a child, but the wasp larvae benefit from an abundance of food. Provided for by the roach. Alive. What an awful fate! Does the cockroach feel these things growing and digesting it from the inside? 

Alright folks. That was your biobunch fix for the day. Of course if you find yourself itching for more please dive into any one of the 98 other posts on this beautiful blog. Today was a bit gruesome! But hay. Nature is not all roses and sunshine... there is a sinister side to it to. 

Hope you enjoyed it, as always I did. 

Biobunch, 

Over and out

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Greetings everybody,

I hope you have had a lovely week and I bet you are all extremely happy that it is finally Friday! On Monday BBC Horizon  showed a controversial and thought provoking documentary on 'Should we close our zoos?'. As expected of BBC it included a range of different viewpoints, but, what was perhaps the most interesting were the views held by myself and you guys. In todays post, I am going to delve a little bit deeper into some of the themes shown in the documentary. Enjoy.

Is animal welfare a priority for zoos? 

It is one of the biggest ethical questions surrounding these institutions, are zoos providing all captive animals the relevant care to satisfy their biological needs? Easier said than done. As more studies are carried out the requirements of each animal become more comprehensive and complex for the zoos to incorporate. Surely, captive populations of animals still benefit regardless on whether all welfare issues are met? Not in the case of captive elephants. Amazingly the longevity of captive elephants is half that of their wild counterparts. Clearly there is a mismatch between what the wild offers and what the zoo can provide, so should zoos continue to keep them?

Detroit Zoo was featured in the documentary as they had to answer that exact question in regards to their two Indian elephants. Captive elephants often suffer from stress and obesity, the excess weight places extra pressure on their sensitive feet causing the onset of chronic arthritis, the Detroit elephants were no exception. Unable to continue on knowing that their elephants were experiencing severe discomfort they relocated both elephants to a sanctuary! 

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Phenomena such as stereotypical behaviour is widespread among captive populations but is commonly seen in the carnivores. 80% of captive carnivores display such behaviour including head swaying, head banging and pacing all of which are thought to originate from stress and boredom. Pacing is the most common, the manifestations of such behaviour are used as indicators for poor animal welfare. Zoos have incorporated enrichment programmes in order to reduce such behaviours and for the animals to carry out behaviours they would do in the wild, these range such as a climbing pole, or tying meat onto a zip wire to initiate chasing behaviour. 

What zoos do when they have to many animals and limited space? 

Surplus animals. It was an inevitability, after all animals are driven by two things: survival and sex. Needless to say captive animals do not need to invest too much energy in survival, so they turn to  breeding if these animals have no contraceptive measures in place then a problem is bound to happen. 

For this part of the documentary, we were invited to look at how Copenhagen zoo dealt with its surplus animals, and the methods were very, very surprising. Copenhagen received heavy criticism when a video was posted on youtube. The video shows a dead two year old giraffe with a single bullet hole to the head- shot by one of the zookeepers. This same giraffe was then dissected publicly for education purposes and the carcass was used to feed the lions. My first reaction was shock, a  reaction that would have been mirrored by the public, then I began to think about it. They explained their reasoning. They can only sustain a certain number of giraffes, sadly they surpassed that number. This individual was chosen based on its genes that were already well represented in captive giraffe populations. Genetic diversity is crucial in deciding what animal is culled, this is because the levels of genetic diversity within a species positively correlates with species survival rates. 

Sad as it may be, this choice comes down to the principles of economics. We have limited resources and too many individuals therefore, you select the individuals that would better benefit the continuation of the species. Using the carcass for the feeding of the lions may seem barbaric, but is it? Giraffes are a natural prey source for lions. Is this an extreme source of recycling? We have a carcass and mouths to feed so, why not give it to the carnivores. There were rumours claiming that another zoo was willing to pay a large sum of money to re-home the giraffe?? 

Can zoos rise to the next greatest challenge, the sixth mass extinction? 

For those who read my blog ‘On the origin of The Walking Dead’ you will know we are fast approaching the next mass extinction event. Every zoo shares the common goal of  education and conservation. Zoos aim to conserve species by maintaining captive populations, in case they need to establish wild populations in the future. But do they work? Captive animals being released into the wild have had very mixed outcomes. Failures of such operations come down to the individual being unable to adapt to its ‘new environment’ such as inability to find food or water. However, when these programmes go right, it is a real celebration such as the reintroduction of wolves to Yellowstone National Park! Successful reintroductions are far and few between. It begs the question that if a majority of the animals in captivity are unable to thrive in their natural environments, are zoos as actively engaged in conservation as they let on to be? 

Reintroduction is the end result of a successful captive breeding programme. In many cases, the stage of reintroduction to establish wild populations have failed. There is no better example of this than the White Horn Rhino. In a story that began in 1975, hopes were high for bringing this iconic species back from the brink of their extinction. The project saw one disaster after another. Many female rhinos became infertile and this resulted in just 5 white rhinos in captivity. Zoo keepers involved in this project expressed the lessons learned, but as I watched Liz Bronnin petting and walking alongside one of the last white rhinos, it was clear how much is on the line. 

Have we peer pressured zoos? 

A key theme presented on ‘Should We Close Our Zoos?’ was who are the zoos prioritising? the animals or the public?  What really surprised me was when Liz told us that 90% of the species that we see in our zoos are not actually endangered! It begs the question, how are zoos helping to conserve endangered species, when the species benefitting from their continued round the clock care are not themselves endangered? 

Think about it, are we the reason why we see certain species in zoos, regardless of  whether they are endangered? When you think of the zoo, your mind instantly goes to the most charismatic species such as the ambassadors for Africa: the Lions, African elephants and so on or perhaps you cast your mind to the forests of India and Bengal Tigers spring to your mind. These species get you to the zoos gates, once there our imagination broadens we suddenly want to see all the other animals on offer: the massive tarantulas, the lesser primates or perhaps the huge Anacondas.  

However, carnivores may be the big money makers, but they are also the ones who suffer the most from captive stereotypic behaviours. Zoos are aware of such things, however they show a reluctance to letting go of their A-list species. Detroit Zoo was heavily scrutinised by other zoos when they sent their elephants away! They said that the elephants brought in a lot of revenue, revenue that can be used for overseas conservation projects and without them they will suffer. They didn’t. Going to the zoo, we do not want to see stressed out animals but are we prepared for zoos to only have species inside of it that they can ensure high standards of animal welfare? Tricky. 

Summing it all up guys...

Like I said before I am Pro- Zoo, because when they are  managed correctly and by people who care about them, they play a vital role. So do I believe that zoos are a dying breed? No! Modern Zoos have had a rocky past, but that does not determine their future. Welfare has never been more in the spotlight. Many zoos now have a dedicated and educated team of: zookeepers, veterinarians and field conservationists. It is all about the next generation, and what better way to inspire these to care even if it is for a day or a week about the conservation of these amazing animals? I do believe that seeing animals in real life and not through a digital medium has the ability to awaken a hidden passion in individuals. Whether it be just how tall a giraffe is or how colourful those tropical frogs are or how amazing a male lion actually is. It may not inspire every child, but for those it does Zoos are needed.  

Zoos are changing, they are incorporating a species habitat more and more into their enclosure design, and dedicated zookeepers continue to strive for the welfare of their animals. At the moment only 3% of a Zoos annual revenues goes onto overseas conservation projects perhaps that will increase as time goes on. 

In the meantime, have a look at Tiger enrichment at ZSL: 

Alright guys, that raps it up please if you can watch the documentary on BBC iPlayer and tell me what you thought!

Have an amazing weekend guys, looking forward to next weeks post already. 

Biobunch,

Over and out

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Greetings everybody,

Happy Friday!! As always. Today is a lovely Biology Behind on a not so lovely disease. Everybody has a similar reaction when they hear the C word, that word being cancer, at least we can say that it is not contagious... or is it. Within this post I am going to enlighten or further consolidate your pre-existing knowledge on the Tasmanian devils contagious face cancer! Or in scientific words the Devils Facial Tumor Disease (DFTD).

First of, what is a Tasmanian Devil? Interestingly, it is the largest carnivorous marsupial mammal and is endemic to the Australian Island of Tasmania. Great but what do they look like? Well, get that image of Taz from Looney Tunes out of your minds, because they look very different to that. So different that you will wonder where Taz came from in the first place, take a look.

Just to let you guys know there are a few disturbing pictures in this post

The rise of a contagious cancer:

In 1996 a photographer came across a Tasmanian Devil with a large facial tumour, however, no significant action was taken - after all cancer has been recorded in many animals. Interestingly, that photographer may have seen patient zero for a disease that has now blown through 90% of Tasmania's devil population. 

Devil Facial Tumour Disease is fast approaching to be the first disease to threaten an entire species with extinction. So, how does a cancer such as DFTD spread and kill 90% of a population? Originally, scientists believed this cancer was being triggered through viral infection similar to how the Human Papilloma Virus causes the majority of cervical cancers, this could explain how it spread through the population so fast. As always, nothing is ever so simple and it turned out that the success behind this cancer was far worse.  

Turns out DFTD is one of two confirmed contagious cancers - you read that right contagious! This disease is transmitted through physical transfer of cancerous cells from an infected individual. Devilish behaviour is a key part to this diseases's success, when two Devils meet it is often a violent interaction resulting in a bite. Interestingly, tumours are localised around a Devils face, neck and inside of their mouth- places that receive the most amount of bites. Once bitten, cancerous cells invades the body of its new host, takes root and does what cancer does- proliferate, exponentially. 

After this proliferation period, death soon follows whether it be starvation due to multiple mouth tumours or the tumour diverting nutrient flow to benefit its own growth. 

Passing of cancerous cells from one devil to another fascinated scientists, how can these foreign cells grow inside an unrelated host, why is this not rejected? Tasmanian Devils have a major glitch within their immune systems- well, the part that deals with detecting foreign bodies. Histocompatibility complexes are the most genetically varied structures found in all jawed vertebrate immune systems, the Devil population all have very low levels of genetic variation- as such their ability to recognise foreign bodies is greatly hindered. DFTD took advantage of this glitch and based their entire transmission route around it. 

Darwinian theory and cancer:

It is easy for us to forget that every living cell is seeking out their own optimal growth, their own evolutionary path- so is cancer. DFTD is a contagious cancer, being contagious has allowed this cancer to achieve an evolutionary win. Cancer as we know it, arises from the hosts own cells, proliferates quickly,and evades our bodies immune system because we have trained our immune system to not destroy our cells. Cancer is self destructive and fairly short sighted, by securing its own growth it further kills its host, and there lie every cancers limitation- it is an infinite cell living in a finite host.  Then comes along DFTD an infectious cancer, a cancer able to spread between individuals within a population, allowing them to outlive their original hosts.

Was this an inevitability for cancer? Infinite cancer cells that were only restricted by their finite hosts have cleaved their bonds. Scary! 

In this case it is the basic laws of natural selection that we all know and secretly love for simplicity. 

Evolution 101:

1. Within a bunch of cancerous cells, some contain a mutation. This mutation allows them to be more virulent, divide faster, acquirer sources better or be passed on to others. 
2. This new mutation allows these select cells to survive and reproduce
3. Eventually, cancerous cells with this mutation are now dominating the population. 

There you have it cancer evolves. Necessity is the mother of invention. 

Devils genes and the search for patient 0:

Alright guys, we are going to go diving into a bit of genetics so stick it out with me. In a bid to understand what is going on in this disease scientist took samples from the tumours of several Tasmanian devils as well as a sample from the devils non cancerous tissue. What they found was crazy! 

Alright, so what we know about cancers in humans is that it arises from our own cells right? Yes. But not for the devils cancer, it turned out that the tumours found on the faces of the devils were as genetically different from their host as I am to you guys! 

In summary, the cancers are genetically different from their hosts tissue but are the cancers genetically different from one another?  The answer is- there not. All the cancers that have been sampled from the Devil population are genetically identical! This means the the devils cancer arose from one individual- patient 0. At some point, some of the cells within patient 0 had mutated, these cancer cells contained a majority of Patient 0's DNA, this devil bit another devil and passed on the cancer and eventually it lead to the epidemic we have today. 

Possible ethical debate?

Recently, many species are being threatened with extinction and a lot of these are down to human activities. However, this one is actually not our fault, this one is completely caused by mother nature herself. The devils population has fallen from 140,000 to 20,000 if this trend continues within the next 25-30 years the Devil will be extinct- without intervention. 

Breeding programmes, and recovery populations have been set up for the Devils as there is no practical way of helping those individuals within the wild. A question raised to me by my dad was, should we intervene? 

Here is my train of thought. This is not a human induced extinction. Extinction is a natural phenomenon. History has taught us that when species go extinct this allows for a speciation event to occur, and thus the process continues to go on. Conservation is a massive issue at the moment, but here is the question should we conserve the species (the Tasmanian Devil) or conserve the natural processes (extinction and speciation)? 

Well that was massive question to start of your weekend, let me know what you think. 

Biobunch, 

Over and out

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Greetings everybody!

HAPPY FRIDAY! Alright guys last week I gave all you lovely readers a look into my mind on how I believe the Walking Dead could have originated. It was pretty awesome. This week we have arrived back to Friday Facts, and guess what... the tigers have taken over! Yep read on and enlighten yourselves on these amazing cats (whilst adoring the pictures I have chosen). Enjoy. 

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Last of all guys. Tigers purr! I know how adorably cute. Well that was Friday facts for my favourite animal! Have an amazing weekend as always guys and in the meantime check out this youtube video of tiger cubs playing with their doggy friends!
Thats Biobunch, 
Over and out. 

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Greetings everybody,

I have wanted to do this post for quite a while to be honest. During university, every student had their 'go to series' in order to distract you from any form of academics, for my housemates and I it was 'The Walking Dead'.

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I am always one for a bit of post apocalyptic drama so I fell right into it, however, I couldn't quite switch my science mind of. Then I realised it, I was using 'The Walking Dead' to revise! It was small things I assure you, like using the rules of group selection theory to explain the zombies that gather in hoards compared to 'lone walkers'. My housemate and I even unravelled the flaw in how our poor characters are killing the 'Walkers' based on the episode where the gang see an MRI scan of how this zombie pathogen takes hold of the mind. It is in this episode, where two things are confirmed. Zombies once turned have no capability of drawing up memories, feelings or emotions simply because those aspects of the brain are dead. Secondly the only parts reactivated after death were the brain stem and parts of the medulla oblongata. 

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But why those two parts of the brain? Quite genius really. Our brain stem and medulla oblongata are responsible for controlling the bear necessities, heartbeat, movement and hunger so- perfect zombie behaviour! OK, so what this means is that the only true way of killing the zombie is not by hacking them in the part of the brain that is already dead, no you need to target your aim to the base of the skull and keep hacking. 

Moving along .... thats not what I really wanted to share with you guys. I was hoping that 'Fear the Walking Dead' would explain how this whole apocalyptic world originated, however, it appears this is not in the cards. Therefore I have taken it upon myself to tell you guys about my hypotheses 'On the Origin of The Walking Dead' be warned a bit of this inspiration was helped along by my favourite zombie movie 'World War Z'. So with that lets think it through!

1. Definitely not a virus even if it behaves like viral meningitis:  

Viruses always want the healthiest host! Yeah I know considering they do not benefit the organism they infect you think they would be happy with what they get, afraid not. What this means is that the remaining population after this outbreak should be those with terminal ailments whether it be an infection or malnutrition, similar to that seen in World War Z. As far as we know, this outbreak has been indiscriminate. So, virus? unlikely.

2. Possibly fungal?

Fungi- the glorious kingdom of fungi. Fungi are largely underestimated they happen to be responsible for some of natures weirdest and often scariest moments. Probably one of the best fungi to tell you guys about is the case of the 'Zombie Ant'. Meet Ophiocordyceps unilateralis  and its poor victim the ant. This fungal pathogen completes its life cycle by infecting the perfect host. It all starts when an ant comes across one of the fungal spores, the fungi infect the ants body and slowly begins its path right up to the ants brain. When there, it gets to making the perfect chemical cocktail... you know the deadly kind. This mixture of chemicals hijacks the central nervous system of its victim causing it to climb to a very high spot on a tree and clamp down. To finish it all off, the fungus grows a spore releasing stalk that explodes out the back of the victims head and the process begins all over again!

Yes, definitely nature at her best and worst. From looking at this life cycle there is a clear fault in trying to pin down the walking dead as being caused by a pathogen of some sort whether it be fungal, viral or bacterial. It lacks the transmission incentive. Think about it, every pathogen shares this in common with the other, that evolutionary drive to spread and infect more. The zombies in the walking dead, simply want to kill and eat, but why would a fungus let alone any pathogen want their host to kill and disembowel a potential other host? It wouldn't. So, it could be safe to say pathogen is off the table.

3. My theory!

OK guys this is the one that I have been excited about since Second Year of Biology. What if this zombie apocalypse is down to our genomes? Lets cast our mind back to the age of the dinosaurs or the age of the wooly mammoth both of which were brought to an abrupt end by mother nature who decided 'your time is up'.  

Now, stick with me guys this may get complicated. The era we live in has been named as the 'Anthropocene' this is because as a race, man kind has manipulated the earths geological and atmospheric processes. In addition to this, we have been the driving force behind many species extinctions and thanks to human induced climate change we are pushing more species closer to the edge. What if Nature decided that this is it? this is our time up? How best to get every single person on the planet? Well, what is the one thing that we all have regardless of colour, religion and sexuality- our genome. Imagine mother natures version of a 'kill switch' hidden inside everyone of our genomes, the same thing that we owe our evolutionary success to, the very thing that led us to be the dominating species on the planet- used against us. The global scientific community is continually providing evidence for the inevitability for the worlds sixth mass extinction event, and the species likely to go extinct... but, what if this mass extinction is reserved for us? 

Our atmosphere has been greatly altered through the exploitation of fossil fuels and release of pollutants, it is no great surprise that this presents us with novel environmental conditions. Is it completely out of the question that the trigger point for the apocalyptic world we see in the series was caused by a combination of the environment and other factors. Similar to the concept of the perfect storm, all these factors coming together just right, to activate that portion of our genome. Varying expression of genetic traits based on internal or external stimuli is not an unheard of science, in fact, quite the opposite it is called the field of epigenetic' and it is amazing! An activation point in our genome, or the expression of a certain gene or genes lead to the dramatic downward spiral of our civilisation. This would explain why everybody has it, as well as the bodies change in its internal environment (i.e. chemicals present) being the final trigger for the full expression of the disease whether it be through a bite or a natural/grizzly death. 

Interestingly, an article recently found that our genome is not 100% made up of 'human' DNA but contains fragments of viral codes! What does this mean? Well, in short - we all have a dormant archaic virus within our genome like a ticking time bomb. Suddenly my crazy hypothesis is not so crazy.

Alright guys you have just had a sneak peak into my mind, and yes science is on it all the time! You think it would get quite tiring but... It doesn't!! Guys as always have an amazeballs weekend!

Biobunch,

Over and out

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