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Feb 26, 2015 Deep diving and the greatest library on Earth

On Wed 14 January 2014, the Museum welcomed a guest speaker to present a special science seminar. Richard Pyle of Bishop Museum, Honolulu, Hawaii, spoke about:

 

...the number of species on planet Earth that remain unknown to science exceeds (perhaps vastly) the number of species that have so far been discovered, let alone formally documented... Within the global biodiversity library, we are at this point in human history like toddlers running through the halls of the Library of Congress, largely unaware of the true value of the information that surrounds us... Taxonomists are the librarians, developing new tools to build the card catalog for the Greatest Library on Earth... What we accomplish within the next twenty years will impact the quality of life for humans over the next twenty thousand years.

 

Richard is an ichthyologist exploring extreme deep reef habitats, a bioinformatician and an ICZN Commissioner, a SCUBA re-breather engineer and and a two-time, two-topic TED Speaker. Watch the film of Rich's fascinating talk in the Museum's Flett Theatre:

 

Feb 20, 2015 World Pangolin Day: Pangolins in Peril
What does the future hold for the Pangolin?  They are rapidly earning the reputation of being the mammal with the world’s highest level of illegal trade, yet many people have never heard of them.   Louise Tomsett, Mammal Curator at the
Feb 18, 2015 The penultimate journey...

It's been a while but we have now the penultimate installment of the Peruvian Adventure by Dave the driver Hall...enjoy.

 

I think that fourth night must have been the first one I've spent at 2,700m and I didn't seem any the worse for it. I tugged at the wooden shutters to see what day five on the road might have in store. Weather: acceptable for driving on dodgy roads. High, thin clouds cut with watery pastels. A shabby old town in diluted blue and sunbleached turquoise. The plaza mayor was just creaking into life. A cluster of women in straw hats held conference outside a grocer's. A policeman heaved open the giant wooden double doors of an eroded old police station, yawned, and spat.

 

I took a cold shower, dressed and started lugging trunks and sample boxes from last night's sorting. Prof. Knapp was already up (of course) dismantling the drier. The daily task of packing seemed a little more arduous this morning. Either the altitude, or the shin-barkingly steep antique stairs. The van was parked in a square pound at the back of the hotel, which looked appealingly like the OK Corral. Sandy had been a little concerned that the truck might not still be there this morning, but the locals seemed harmless enough to me, if not exactly chummy.

 

The growing light revealed our hotel to be of a certain vintage; much of the rear was semi-derelict and empty. I creaked back and forth with my boxes through creepy cavernous dusty backrooms, using the return trips to investigate dark passages and musty staircases leading nowhere, the only sounds my wheezing and the drip of an old tap. And here an appealingly dilapidated old dining room-dance hall I could imagine thronging with local revellers.

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Morning in Celendin.

 

After breakfast I took a few moments to explore the town, too. It might be old hat for the Dr Livingstones in our midst but I was unlikely to set eyes on the place again. Erica likes telling me how amusing it is reading my rhapsodic perspective on what she sees as routine grubby fieldwork: I see cascades of mountains; she sees dirty socks drying on the dashboard.

 

(Erica here - not exactly how I phrased it - he was bemoaning us for failing to see the beauty all around us - Sandy and I were concentrating on flies and spuds )

 

The market was already open for a day's easygoing trade. I ambled over. Three schoolboys kicked a burst ball to each other on the way to classes. The policeman hadn't moved. Stallholders unhurriedly erected awnings and set out their wares along the narrow thoroughfares, the alley-tunnels filled with the pungent aroma of meat, overripe fruit and hawker-stall breakfasts. I bought plump oranges and tomatoes for lunch from one of the impassively leather-faced vendors and wandered back to the hotel, ready for another day behind the wheel.

 

But no! Erica announced she'd be driving today, to 'give me a break'. The cheek. I protested firmly, in my quietest voice. This felt like cheating, but I was anticipating incredible scenery, ahead so I didn't flap.

 

(Erica again - they are long days driving- even we are not that nasty to make him drive continuously)

 

In contrast to other towns thus far it was a fair doddle finding the route out of town. Without at least two simultaneous sets of directions being offered in each ear, the going seemed somehow easier. Being fair, it wasn't hard to navigate. There was little traffic, and thanks to the colonial grid system we simply had to find the edge of the town and keep going until we hit a road going east.

 

Nevertheless, this road looked unpromising – a narrow back-street cluttered with the detritus of townsfolk's lives: bits of motorbike, smashed agricultural implements, underfed dogs...

 

But here a sign, which told us it was a mere 150km to our next stop, Leymebamba, and presently we started climbing.

 

The narrow road wound up again through foothills scarred with gold-mining quarries, many illegal. The locals had been protesting for some time, largely to deaf ears, that these mines – many sponsored by American multinationals – are polluting the water supply.

 

Above the scarred hillsides we rose... the road surface was perfect and I couldn't help thinking what an epic bike ride this would make for the stout of heart. Eventually the treeline gave way to rousing views of Celendin far below, where the light-blue double steeple of the church in the town square poked above the ramshackle rooftops. The town nestled in a half-bowl surrounded by hills. It must have looked attractive to the early Inca settlers and, unfortunately for them, the Spanish too. The head of the valley ended in an unseen drop, and far beyond were mountains whose peaks seemed oddly level with the town itself... now it was clear how high up the town was.

 

Still we climbed, this time without finding any locals to pester about their potatoes. Spying as yet no specimens, we meandered upward and upward, through rugged moorland, ever closer to the clouds that before had seemed so far off. As the sun finally renewed hostilities and the clouds began to leak a bit of sunshine, we reached a high pass of about 3,500m where a tiny village sat incongruously amid the rugged landscape, complete with a tiny football pitch and neatly planted conifers. The place had a strangely manicured feel.

 

Then, suddenly, the other side. As we breached the other side of the pass, a completely different panorama opened up. A dramatic series of valleys and mountain ranges rolled into the east, rib upon rib wreathed in mist, multiple horizons fading toward the Amazon. Somewhere to our right, far below and well beyond view, the Marañón River was thundering on its 1,700km looping journey toward the king of rivers. My head span at the spectacle. Sandy and Evelyn discussed tomatoes. Erica drove on without comment.

 

Our way wasn't getting any wider. As we wound downwards, hugging the cliffsides, the road only narrowed further. The bends were like fishhooks, and here and there were patches where the roadworks had not reached or where recent repairs had simply slid down the cliff. There were no barriers to protect motorists from the yawning 1,000-foot drops a matter of inches from the wheels. Superfluous roadsigns warned us to slow down and keep right. Erica didn't need much encouragement. Everyone in the car seemed to become silent. I tried to look far ahead to see if anything was coming the other way. We could only imagine what it must be like for lorry and bus drivers.

 

I was beginning to enjoy myself.

 

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A yawning 1,000-foot drop inches to the left.

 

In the clouds now. I like being in clouds, but it doesn't help with the driving. Breaks in the mist revealed teasing glimpses of dark, sheer mountainsides. Here and there the sun poked through and a rainbow made a perfect technicolor arch over the road.

 

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Driving through the Peruvian mountains.

 

Then just as suddenly, out of the mist, full sunshine, the scenery changing from hairpin to hairpin. We were descending toward a lush shoulder of high land, an upper valley nestled in a crown of mountains far below, dotted with tiny farmhouses and quiltwork cornfields, into which the road descended in a series of insane switchbacks. It was a perfect lost valley; a prime spot for Eldorado.

 

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A prime spot for Eldorado.

 

I still have no idea how Sandy spots specimens from the car even at the modest speeds we were achieving. But at last Prof Knapp bade us stop for our first samples amid a gradually drier landscape.

 

The sun was melting the clouds away and the morning was mellowing nicely. Nearby, an allotment of sorts, a small bungalow and what I thought were petrol pumps. The immediate area was lush, catching runoff rainwater in a small series of irrigation ditches. Prime mozzie territory, I thought. Again, parts of the area had been cleared recently – the solanum species again proving keener than mustard to move in quick on new space.

 

My ridiculous sample notes about the sampling area – for 'twas my job – read: “A small irrigation ditch is nearby and a 'petrol station' nearby also.”  I see now it was not a petrol station, but someone's dwelling, but their toilets seemed public enough at the time.

 

Sandy and the Fly Girls exited, rummaged in the back for Sucky and Sweep, then set off into the undergrowth. Evelyn swished gamely. Erica bothered a bush. I made notes. Sandy snagged some excellent samples of Solanum dilleni. I went to the toilet again.

 

(Erica once more - many conversations on fieldtrips revolve around toilets - how often you need to go, the facilities etc)

 

On we went. As we sank riverwards, hopes rose in the back of the truck that the ever-more arid terrain may harbour the tomato relatives we had encountered in similar habitats earlier in the trip: habrochaites perhaps. It was getting drier and drier. I prefer the lush stuff up in the mountains.

 

We fairly freewheeled to the next stop a couple of miles hence, where a sharp bend in the road concealed a small clutch of solenum arcanum known from Sandy's notes to be in this location many years previously. It was still there. All manner of insects waited to be sucked from the bushes, but nearby sat a sizeable troop of Homosapiens Peruensis, taking a break from mending the road. They were much animated by the sight of Erica's immense suction apparatus. We had disturbed the species in its natural habitat, so had to bear with good grace the sniggering and what I imagined to be Spanish double entendres. The Challenges of Fieldwork.

 

My notes say we came away with some samples of “Solanum simplefolium” but, according to Google, this doesn't exist. That's a shame – I liked that name. I can only imagine it was Solanum pimpenellifolium. This sports little purple flowers and tiny tomatoes – tomatillos – which are edible. It's a really close relative of our tomatoes. Indeed, it is sometimes called a wild tomato.

 

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Some Peruvian geology.

 

Further we sank toward the Marañón in our search for tomato and potato data, through spectacular peaks and pyramids of twisted volcanic rock where lava seams poked through like ribcages, past abandoned pasture and the occasional hungry-looking donkey picking through the brush.

 

At last we reached the valley floor, at the village of Chacanto in the district of Las Balsas – gateway to the Amazonas region. It was now all firmly semi-desert, reminiscent of parts of Nevada or Utah, catching the full ferocity of the sun. It felt like being stir-fried. The river looked inviting, but the Marañón slides through at a good clip here even in the dry season. It is a mere stream compared with what it would become downstream, but the bridge that spans it is a good 100m in length. We rolled over the bridge, stopped only a few minutes for a coffee in the sleepy village, and went on our way. We still had a long way to go...

 

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The Marañón River at the bottom of the valley.

 

Erica - since writing these blog pieces we have been analysing some of the data and trying to figure out what some of the insects that we sampled are. It has taken months to do this and there have been at least 9 people so far going through the insects. many are about to be sent of to specialists across the globe. Upstairs from where I am typing this at my desk we have two people imaging some of the specimens before they are sequenced for their DNA....its a very exciting time for this project.

Feb 11, 2015 Ocean acidification damages the growth of colonial marine life

A species of bryozoan transplanted to an area with increased ocean acidity has been found to grow at half the rate of those living in normal ocean conditions.


Bryozoans are coral-like animals that live in colonies and build their skeletons out of calcium carbonate. An international team including Museum researcher Dr Paul Taylor transplanted several budding colonies from their normal homes in the Mediterranean to an area near an active volcanic vent in Italy.

 

The undersea vent expels heat and carbon dioxide, simulating the global surface ocean acidity predicted for the year 2100 as a result of increased anthropogenic carbon dioxide emissions. According to Dr Taylor:

Entire ecosystems are threatened by ocean acidification, and this will have economic consequences because animals such as bryozoans are often habitats for the juveniles of commercially exploited fishes and crustaceans or may be in their food chains.

20150211 Bryozoan Calpensia nobilis © Lombardi et al..jpg

The bryozoan Calpensia nobilis showing normal growth at the leading edge © Lombardi et al, 2015.

 

During a three-month experiment, the bryozoan colonies around the vent suffered slower growth rates, the absence of some growth stages, and the corrosion of their skeletons. However, individual zooids – the tiny creatures that build the colony – were longer than normal.

 

Dr Taylor thinks this could be an indication of adaptation by the bryozoans to the changing environmental conditions. The colonies seemed to invest more energy in completing zooids that had already started to form rather than budding new generations. In other words, they were strengthening the existing colony rather than expanding.

 

Longer studies are needed along with more detailed information about how the colonies are reacting to possible future scenarios. Said Dr Taylor:

With this information, better predictions could be made of organism survival and evolution, and thus ecosystem changes, loss or survival in a changing world.

The research is published today in the journal Royal Society Open Science.

 

Jan 26, 2015 Forever Flies – Crime Scene Investigation

Hello Super-flies and Parasites fans!

 

We are back with all things nasty from the Parasites and Vectors division here at the Museum. There have been some exciting developments in the New Year, most importantly the launch of the Museum’s brand new website!

 

This is another ‘Forever Flies’ series of blog posts, bringing you news from the Museum'sforensic entomologygroup.

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Forever Flies is our forensic entomology blog series. This image shows a carrion-eating greenbottle blowfly.

 


Forensic Entomology

You will remember from my previous Forever Flies post that forensic entomology is the study of the insects and arthropods found at a crime scene. The most common role for Museum forensic entomologists is establishing a minimum time since death in suspicious cases, by analysing the carrion insects on the body.

 

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Blowflies use the bodies of dead animals to grow and develop. The rate at which they do this, going from egg to larva to pupa to adult fly, is pretty consistent and depends largely on ambient temperature. Forensic entomologists use this to determine the minimum post-mortem interval (PMImin), which helps crime scene investigators determine approximate time-of-death.


Thanks to entomological expertise (Greek – entomo = insect, logos = knowledge) scientists can collect insects from a corpse and/or crime scene, determine what stage in their life cycle the insects have reached and, using their knowledge on the duration of each stage of the insects’ life cycle, determine how long ago the parent insect laid her eggs on the corpse.

 

This gives an incredibly useful estimate of the minimum amount of time this body has been dead (minimum post-mortem interval - PMImin), which helps crime scene investigators determine approximate time-of-death. The more accurate this minimum post-mortem interval is, the more accurate the time of death can be. Knowing time of death can focus the police investigation and suggest the likelihood of a suspect’s involvement.

 

Scientists can also use these insects to determine if the body has been moved since death and how long a body was exposed above ground before burial.

 

Metamorphosis in pupae


Flies spend over 50% of their developmental life in the pupae stage, protectively encased inside a hard shell (called a puparium) where they slowly transform from a maggot into a fly in a process called metamorphosis (Greek again - Meta = change, morphe = form).

 

A puparium looks quite bland and boring but underneath there are all sorts of wonderful things going on. Scientists can remove the shell and, using traditional microscopy, take a look at the fascinating changes of metamorphosis. But this process does destroy the pupa sample, making it difficult to work out how long it takes for the pupa to go through the different stages of metamorphosis.

 

Scientists know that the length of time metamorphosis takes to complete really depends on temperature, the question is can we use our knowledge of the process to pinpoint a more accurate estimate of PMImin?  What forensic scientists need is a standardised method to work out:

  1. At what stage in the metamorphosis process is the pupa
  2. how long did it take to reach this stage

 

If these two points can be determined then scientists can provide a far more accurate PMImin.

 

The ‘MORPHIC’ project

 

Dr Daniel Martin-Vega, a forensic entomologist, has joined the Museum from the University of Alcalá in Spain to research carrion fly pupae and to develop a standardised protocol for aging pupae (as in determining their age) that can be used by forensic scientists. This project is called MORPHIC and is funded by the European Commission through a Marie-Curie fellowship.

 

It sounds all neat, logical and tidy but there is A LOT of work and dedication involved!

 

For this projectDaniel is raising two species of the carrion-loving blowflies, the greenbottle blowfly Lucilia sericata and the bluebottle blowfly Calliphora vicina. The flies live in netting covered cages, where they feed and reproduce whilst he monitors them.

 

Daniel feeding flies_resized2.jpgDaniel showing me the Diptera (insect) culture room. Each netting-covered box has a species of carrion blowfly in it. He is researching the pupae of these flies to see if he can improve the estimate of  PMImin and thus improve the information given to crime scene investigators.


He also has to collect the post-feeding maggots and place them in a box with some nice clean soil for them to happily grow until they are ready to start the metamorphosis process. These boxes are then placed in a cabinet kept at a specific temperature. Since the rate of metamorphosis largely depends on temperature it is very important the Daniel can control this environmental factor in order to document the rate of change at different temperatures.

 

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The maggot house! This is a comfy box with soil where maggots crawl around and prepare to pupate. When the maggots start pupating Daniel has to come in every 6 hours or so to monitor and collect them for his research

 

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Blowfly maggots and pupae.

 

 

Once the maggots start to pupate Daniel has to collect the pupae:

 

I come in every 6 hours when the maggots start to pupariate in order to collect blowfly pupae at 6-hour intervals during the first 48 hours after puparium formation (the period when the greatest morphological changes of metamorphosis occur). Luckily, I only do this from time to time. After that, the collection of pupae is just daily until the adult flies’ emergence.

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Daniel sieving out the pupae from the box.

 

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Maggots and pupae, oh my!

 

Watch those maggots wriggle about!

 

He then has to sieve out the pupae from the soil and carefully place them in a petridish labelled with the blowfly species name, the date collected and the time collected. These petridishes are also placed in the special temperature-control cabinet.

 

 

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Daniel has separated out the pupae of different species of blowfly. Each petridish with pupae has the species name, the date collected and the time collected.

 

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The petridishes are kept at a specific temperature. Since the rate of metamorphosis largely depends on temperature it is very important the Daniel can control this environmental factor.

 

Daniel uses the Museum’s wonderful micro-computed tomography (micro-CT) scanner to take detailed images of the inside of the pupae without destroying them. A micro-CT scanner is a type of X-ray scanner that produces 3D images, much like a hospital CAT scanner, but at a much smaller scale and a higher resolution. The results are like 3D microscope images! 

 

Thomas Simonsen and Daniel Martin-Vega analysing CT images of 5 pupae.jpg Thomas Simonsen and Daniel Martin-Vega operating Micro-CT scanner.jpg

Daniel with colleague Dr Thomas Simonsen using the Museum’s micro-CT scanner to look at 3D images of blow-fly pupae. The micro-CT scanner uses x-ray technology to produce 3D 'microscopy' images at high resolution without damaging the sample.

 

By using the Museum’s micro-CT scanner Daniel can take these detailed images at specific time points of the metamorphosis process.  He will then have a catalogue of images of the blow fly pupal development at specific temperatures. This catalogue of images will be used to develop a standardised tool to determine the age of blow fly pupae. Then when pupae are collected from a crime scene, they can be compared to this catalogue and scientists will be able to determine how long the fly has been in its pupal stage. Giving scientists a more accurate estimate of PMImin! Ta daaaaa!

 

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Micro-CT scanner images of a bluebottle blowfly Calliphora vicina pupa. The one on the left is at 48 hours, the one on the right at 216 hours. You can see the difference in development between the two pupa images.

 

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Dorsal micro-CT scanner image of a blowfly pupa.

 

I hope you enjoyed this post. If you fancy a stab at a bit of CSI work why not check out the Museum's Crime Scene Live After Hours events.

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