Skip navigation
You are here: Home > NaturePlus > Blogs

Blog Posts

Blog Posts

Items per page
1 2 3 4 5 Previous Next
0

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.

 

0

I bet you have never wondered what microorganisms are living on London's iconic buildings. I certainly hadn't given it much thought until this August when I joined Dr Anne Jungblut, Lucy Robinson and volunteers Josie Buerger and Stephen Chandler, for an urban field trip. We visited four of London's iconic buildings to collect microorganisms and find out what on earth is living there. This would be the start of our citizen science project, The Microverse; a scientific exploration of the microbes that occupy our built environment across the UK.

 

DSC_0542.JPG

The Microverse team collecting samples from Westminster Abbey. Image credit: Josie Buerger

 

The Tower of London, The Gherkin, St Paul's Cathedral and Westminster Abbey all kindly accepted our request to swab their walls and DNA sequence the biofilms that we found. We carefully selected different types of building material and different sides of the buildings, so we could compare the community of microorganisms from these different aspects of the built environment. We took samples from different aged buildings, from cleaned and un-cleaned walls and even from the roof of St Paul's Cathedral.

 

DSC_0527.JPG

Collecting samples from St. Paul's Cathedral.

 

Samples were collected by dampening a cotton wool swab with sterile water and then rubbing this swab against the surface of the wall. The head of the cotton wool swab was then put into a tube of DNA preservative. Samples were stored in the freezer of the Museum until they could be DNA sequenced in the labs. We are currently analysing the lab results to see what communities of microorganisms were living on the different buildings. Will The Gherkin have less microorganisms than the Tower of London? Will south facing walls have more microorganisms than north facing walls? We hope to tell you what we have found very soon.

 

DSC_0303.JPG

Dr Anne Jungblut adding sample to DNA preservative at Tower of London. Image credit: Josie Buerger.

 

The Microverse is a citizen science project, suitable for A-level Biology students or equivalent, and community groups. The project takes you out of the classroom to gather microorganisms for DNA analysis, as part of our cutting edge research into the biodiversity and ecology of the microbial world. It's free to participate and you can find out more about the project and how to take part here.

 

Jade Lauren

1

A team of geologists from the Museum and Imperial College are in Mexico carrying out  fieldwork at two of the most active volcanoes in the world: Popocatépetl (Popo) and Colima. Catch up with their adventures in this series of blogposts.

 

This uncomfortably oblique photograph marks the end of this year’s fieldwork at Popo. As you can see, we have been extraordinarily successful in collecting samples:

Trunkful of Rock.jpg

All in all, we have collected twelve boxes full of pumice and lava in the last two weeks, each of them weighing about 20 kg!

 

Moreover, not only have we been doing well in bagging rocks, but we also made many important field observations, such as the relation of the different volcanic units in time and space. This is essential for the proper handling and analysis of our samples.

 

As soon as our heavy load arrives at the Natural History Museum, I will crush the rocks into tiny pieces and examine them using different types of microscopes. We are confident that this will tell us intriguing stories about how Popo works. The adventure has just begun!

 

But first, we will drive this trunkful of rocks to Mexico City, where we will also say ‘muchissimas gracias’ and ‘hasta luego’ to Julie, who will fly back to London, and also to Hugo and Guillem, who will stay in Mexico City. Chiara and me will stay in Mexico for another week, which we will mostly spend in Colima. There, about 500km West of Popo, the ‘Fuego de Colima’ volcano is currently very active, with several small eruptions every day. We are excited to go there and see some nice ashclouds, and of course, we will keep you posted about our ventures in West Mexico!

0

NHM EARTH SCIENCES SEMINAR

 

Unravelling global warming through soil mineralogy: A case study from a proglacial valley in the Swiss Alps

 

Dr Christian Mavris, Marie Curie Fellow (ES, NHM)

 

Tuesday 10th February - 4.00 pm

 

Earth Sciences Seminar Room (Basement, WEB 05, the previous Mineralogy Seminar Room)

 

Investigations in Alpine soils indicate that mineral weathering is much faster in ‘young’ soils (<1000 yr) than in ‘old’ soils (10,000 yr). However, little is known about the initial stages of weathering and soil formation, i.e. during the first decades of soil genesis. Due to the continuous retreat of the Morteratsch glacier (Upper Engadine, Swiss Alps), the proglacial area offers a full time sequence from 0 to 150 yr old surfaces. The area is well documented regarding vegetation and soils.

 

The glacial till has an acidic character (granitoid parent rock). Mineralogical measurements were carried out using a broad range of analytical approaches, from XRD to wet chemistry to cathodoluminescence and Nomarski DIC microscopy. Specifically, cathodoluminescence and Nomarski DIC microscopy were used for the first time on minerals involved into an early pedogenic process.

 

This work clearly demonstrates that in cryic, ice-free environments, chemical weathering rates are high, leading to the formation and transformation of minerals. This clearly influences pedogenic processes to a remarkable extent – and thus, is linked to the settlement of life in previously deglaciated (and extreme) areas.

 

 

More information on attending seminars at http://www.nhm.ac.uk/research-curation/news-events/seminars/

0
DBP_2015_c-3.jpg
Polymerization in hydrothermal conditions: Darwin's prescient idea.

Dave Deamer, Department of Bimolecular Engineering, University of California, Santa Cruz CA

 

In an often quoted note to Joseph Hooker in 1871, Darwin speculated that life may have begun in a "warm little pond." We have tested this idea in simulations of fluctuating hydrothermal fields associated with volcanism. We found that the chemical energy available in such conditions can drive polymerization of ordinary mononucleotides into surprisingly long oligonucleotides resembling ribonucleic acid (RNA). The polymerization occurs in lipid environments so that the RNA-like polymers become encapsulated in membranous compartments to form protocells, the first milestone on the evolutionary path toward primitive cellular life. 


Energy and Matter at the Origin of Life

Nick Lane, Department of Genetics, Evolution and Environment, UCL

 

There is a paradox at the base of life. Membrane bioenergetics - the use of ion gradients across membranes to drive carbon and energy metabolism - are universal, but membranes are not. Radical differences between bacteria and archaea in membrane chemistry and active ion pumping suggest that LUCA, the last universal common ancestor, may have used natural proton gradients in alkaline hydrothermal vents to drive growth. I will outline a possible scenario for the origin of life in this environment, and present some experimental and modelling results which suggest that proton gradients could have driven the transition from geochemistry to biochemistry, and the deep divergence of archaea and bacteria.

Location:

Flett Lecture Theatre, Natural History Museum, Cromwell Road, London - Map

Poster:

Download a copy of the poster here - Poster

0

Cover_Evolve22.jpg

 

 

 

 

The latest edition of Evolve is out (Issue 22) and the Library and Archive collections (and staff) feature in many of the articles:

 

Dorothea Bate rediscovered map

 

Interview with our Special Collections Librarian, Paul Cooper

A first for the Library and Archives team!

 

Magnificent Monsters: The Crystal Palace Dinosaurs by Karolyn Shindler

 

Snapshot of war: the 100th anniversary of World War One by Karolyn Shindler

 

Cousins across the centuries: the pigeon and the dodo, a strange family tale

 

Evolve is available from the Museum shop or free when you become a member.

0

Palaeo-ecosystems in Pleistocene Europe: Insights from stable isotopes of large mammal fossils

 

Prof. Hervé Bocherens, University of Tübingen, Germany

 

Tuesday 3rd February - 4.00 pm

 

Earth Sciences Seminar Room (Basement, WEB 05, the previous Mineralogy Seminar Room)

 

The climatic fluctuations of the Pleistocene have caused dramatic changes in the ecosystems of Europe during the last million years. These ecosystems, cold or warm, included a high diversity of megafauna, in contrast to recent ecosystems under similar climatic conditions.

 

NaturalHistoryMuseum_PictureLibrary_024715_preview.jpgTooth of a woolly mammoth (Mammuthus primigenius)

 

To gain a better understanding of the functioning of these ecosystems with no modern analogue, the isotopic composition in carbon, nitrogen and oxygen of the large mammal fossil bones and teeth were used to document key aspects of their ecology, such as habitat, diet preference, niche partitioning, and predator-prey interactions. In addition, isotopic analysis of fossil hominids and their prey allows the reconstruction of subsistence patterns and inferences on the possible anthropogenic impact on the environment.

 

More information on attending seminars at http://www.nhm.ac.uk/research-curation/news-events/seminars/

0

A team of geologists from the Museum and Imperial College are in Mexico carrying out  fieldwork at two of the most active volcanoes in the world: Popocatépetl (Popo) and Colima. Catch up with their adventures in this series of blogposts.

 

After our dirty but successful pumice-rich first week at Popocatépetl, we were all happy to get that dust off our shoulders and start chasing the various lava flows that make up most of the volcano edifice. Now, if the whole volcano is built by lava flows, it should be really easy to find these rocks, shouldn’t it? The short answer is: no. The longer, picturesque answer will take you into the wild, rough and bumpy world of Popo’s lower flanks, where a good rock is as hard to find as a sleeping baby lion in the vast African savannah. Join us on the magical ROCK SAFARI!

 

Early in the morning, when Popo is still entangled by the night’s misty claws, we make our way from the hotel in Amecameca towards the south-eastern flank of Popo, the land of the sneaky rocks.

 

savannah.jpg

Somewhere down there they are hiding: the Popocatepetl lava flows!

 

No Road.jpg

On the lookout for rocks: moving in this terrain makes you reconsider what you may call a ‘road’.

 

What makes it so difficult to find these lava flows is the fact that most of them are buried by a thick cover of the Popo pumices (not again!) and lahar deposits. So in many cases the only thing we can find on top of these dirty deposits are loose boulders of rock, which we can’t even be sure belong to the place we find them lying. A tedious job requiring lots of caution!

 

Kill 1.jpg

An easy catch: can you spot the rock?

 

Kill 2.jpg

Julie finds a rock that has tried to hide away from our hammers…

 

Kill 2a.jpg

…we took care of it.

 

Such a seek-and-destroy campaign can easily take a couple of hours for one lava flow and is not necessarily successful. However difficult it may be, when you finally spot a nondescript, lichen-covered rock specimen, the adrenaline you feel while smashing it into pieces to see what species it is pays off generously.

Kill 4.jpg

Another boulder from a Popo lava flow successfully tracked down.

 

One factor that contributes to our (otherwise rather questionable) sense of adventurism during this rock safari is the daily recurrence of a group of local forest watchdogs roaming around the terrain. The first time they came, they only surrounded our car with a grim look on their faces, checking if we were hunters (if they could only know!).

 

The second time, they had machetes (they were cleaning the roads from vegetation) and we had to give them some money so they’d let us pass. The third time, it was already getting dark, and they had shotguns to guard a road against any people with mischief in mind. We certainly didn’t at this point. The good thing is that by now they know us and they greet us cheerfully every time we pass them.

 

easy catch.jpg

Obviously, we weren’t keen on photographing the shotgun watchdogs, so instead we present evidence that some lava flows are not good at hiding away. This the Nealticán lava flow, which is the most recent of Popocatépetl’s lava flows (in geological terms, ‘recent’ means younger than 2,000 years). Because of its young age, it is not covered by a lot of deposits and is thus widely exposed. Unfortunately, this flow is the exception to the rule.

 

In this manner, we have chased down a couple of lava flows in the past few days. We are very happy with the outcome of our rock safari and can’t wait to introduce these samples to their new temporary habitat while they are shipped to the UK: cardboard boxes!

0

You could say that this month's post is written in the spirit of January detoxes and body cleanses and all that healthy, New Year resolution-y stuff. It is also, I should mention in advance, not a post for the faint-hearted, so if you are of a nervous or squeamish disposition, you should probably look away now.

 

You could say that this month's specimen is the most intimate and personal one I've ever written about. It is, I believe, unique in our collection as being the only specimen donated by a member of staff having been sourced from his own body.

 

I'll let the protagonist - former Museum Science Educator and current Discovery and Learning Officer at ZSL London Zoo, Theo Blossom, take up the tale:

It was May 2012, 7.30 in the morning. My alarm had gone off in my university campus dorm room, where I was studying for my Masters in Conservation Science. I got up out of bed, and I started to walk across my room. Two steps across the floor, I felt something… something between my legs, something dangling... So I put my hand down my underwear, and I felt something coming out of my… well, my bum! At this point I began to feel a little alarmed.

 

I started to pull at it tentatively. Whatever it was kept coming and coming and coming. It was a bit traumatic, but  finally, "it" came out. All nine inches of it! I held it up in front of my face, in disbelief - and then - it gave its last wiggle of life! That was when I began to freak out.

 

What Theo had just bravely removed from his own behind was (it would later be confirmed) a roundworm, Ascaris lumbricoides. He named it Judas and put it in a flatmate's (n.b. 'special thanks to Izzy') Tupperware container.

 

roundworms.jpg

An example of the human roundworm, Ascaris lumbricoides, (however, not 'Judas'). This species can grow up to ~40 cm (16 inches).

 

A visit to the campus doctor confirmed the aforementioned species type and also allayed some of Theo's fears about this strange creature that had been living in his body.

(The campus doctor) was a very well-spoken old boy who was probably, quite frankly, bored of handing out condoms. So when I slapped down Izzy's Tupperware box in front of him he became quite animated. Thumbing through a rather tatty book of potions he said: "Mebendazole, that will kill them. That is, if you want to kill them? It seems a shame. This little fella has probably been providing you a service - I presume you're fit and healthy with no allergies?"

 

It's all about the idea of "ecosystem services", Theo in turn explained to me. That is, the benefit that human species gain from resources and processes supplied by ecosystems. In this case, exposure to parasites (roundworm) keeps our immune system active and therefore better able to cope with other foreign bodies, from everyday pollen to more harmful bacteria.

I've since worked out that this little dude was inside me for two years. I didn't know. He caused me no problems. Coincidently or not, I have no allergies. The reality is our bodies are riddled with living organisms which are there all the time but do us no harm whatsoever. In fact, they benefit us in many ways.

 

After learning all this, I began to feel a bit bad. This little guy has been part of a marvellous little ecosystem that was boosting my immune system, and I'd just ended the party.

 

But Judas - who is actually female, not male - lives on, in body, and, technically, in spirit, in the Museum's specimen collection. After speaking to a Museum expert in parasitic worms to find out more about Ascaris lumbricoides, Theo was encouraged to donate his find (or should that be harvest?) to live on in perpetuity behind the scenes of the Darwin Centre, among our more than half a million other parasitic worm specimens.

 

theo-4_700.jpg

theo-5_700.jpg

Theo revisiting his roundworm, affectionately known as Judas, in the Museum's Darwin Centre this week.

It's a dream come true for anyone into natural history to have their name recorded in the scientific scriptures of the Natural History Museum, alongside the likes of Charles Darwin. I just didn't think it would be quite like this!

 

My great, great grandchildren, can, if they wish, in years from now, walk into the Museum and request to see Judas in all her glory. My great grandchild will ask my granddaughter: "Mummy, can we go and see great Granddad's worm?" And from beyond the grave, that will be a proud moment for me.

 

roundsworms-bottom_700v2.jpg

2roundsworms_700v2.jpg

'To see "Ex Homo sapiens (Theo Blossom)" written on a specimen jar at the Natural History Museum is pretty awesome!' Theo said, adding: 'She looked a bit smaller than I remember, though.'

0

An innovative jaw bone study has revealed that a Jurassic fish ate like modern sea breams.

 

By measuring the jaws of 89 examples of the fish Dapedium, including specimens from the Natural History Museum, University of Bristol undergraduate Fiann Smithwick was able to recreate how it ate. He said:

My work indicates that Dapedium was well adapted to crush shells, feeding on bivalves and other hard-shelled creatures that it could scrape from the sea floor.

Dapedium-700.jpg

A Dapedium specimen from our collections.

 

The good preservation of the fossil fish specimens allowed Fiann to use a mechanical model developed to understand modern fishes in his study. By calculating the positions and orientations of the jaw muscles, he was able to determine that Dapedium's jaws moved slowly but strongly, allowing it to work on the hard shells of its prey.

 

In contrast, other families of fish can have faster but weaker jaws, adapted for feeding on fish prey that are speedier and slipperier.

Ancient fish, historic collections

Dapedium lived 200 million years ago during the Jurassic period, and is one of many ancient sea creatures discovered by Mary Anning in the rocks around Lyme Regis, Dorset.

 

Museum fossil fish curator Emma Bernard said:

Dapedium is an iconic fossil from Lyme Regis and can be found on many postcards and souvenirs from Lyme Regis. If you are lucky you may even find one when fossil hunting in Lyme Regis.

Viewed from the side, Dapedium was a flat, deep-bodied fish that could grow up to half a metre in length. It had jutting front teeth with a mass of blunt teeth behind. Emma said Fiann was a pleasure to work with as he grasped the importance of our historic collections:

This study would not have been possible without the extensive fossil collections we house, which show a variety of characteristics that Fiann used for his study. His work helps us build up a picture of how Dapedium lived and what it ate.

The study appears in the prestigious journal Palaeontology - a rare achievement for an undergraduate.

0

Finds from Taiwan and Israel shed light – and confusion – on the story of ancient human species.

Find 1: A mysterious jawbone from Penghu, Taiwan

Discovered by chance by fishermen off the coast of Taiwan, an unusually thick and primitive human jawbone shows a challenging mix of features. While no DNA has yet been recovered from the specimen, its characteristics make it difficult to classify into existing groups.

 

The jawbone is short and wide, with a thick body and large teeth. It dates within the last 450,000 years, and most likely within the last 200,000.

Jawbone-Split_3179032b.jpg

The jawbone, left, and a reconstruction of the jaw, right © Yousuke Kaifu.

 

A partial Homo erectus skull from the Chinese mainland has some large associated teeth and could be 400,000 years old, so the new jawbone may belong to the same group. But it could also be one of the elusive ‘Denisovans’, a group known only by DNA from a fragmentary fossil finger bone and two very large molar teeth in a Siberian cave.

 

Museum human origins expert Prof Chris Stringer said this could be an interesting development:

I have considered the Denisovans as an Asian sister group of the Neanderthals, and like them, derived from Homo heidelbergensis, but if Penghu is indeed a long-awaited Denisovan jawbone, it looks more primitive than I would have expected.

He said of the find:

As the authors note, this enigmatic fossil is difficult to classify, but it highlights the growing and not unexpected evidence of human diversity in the Far East, with the apparent co-existence of different lineages in the region prior to, and perhaps even contemporary with, the arrival of modern humans some 55,000 years ago.

Read the original paper

 

Find 2: The skull of a possible early migrant, from northern Israel

A later and much better-dated specimen, the partial skull of an early modern human from Manot Cave dates to a time of migration out of Africa and interbreeding with Neanderthals. At about 55,000 years old, it sits comfortably in the timeframe estimated for early modern human and Neanderthal interbreeding, 50-60,000 years ago.

 

The skull itself has characteristics indicative of early modern humans, and without DNA it is impossible to say yet whether interbreeding with Neanderthals had an impact on the individual. Nonetheless, Prof Stringer said it is a critical find for examining possible migrant populations:

Manot might represent some of the elusive first migrants in the hypothesised out-of-Africa event about 60,000 years ago, a population whose descendants ultimately spread right across Asia, and also into Europe. Its discovery raises hopes of more complete specimens from this critical region and time period.

Read the original paper

 

Related human origins posts:

1

A team of geologists from the Museum and Imperial College are in Mexico carrying out  fieldwork at two of the most active volcanoes in the world: Popocatépetl (Popo) and Colima. Catch up with their adventures in this series of blogposts.

 

Time flies – we've already been here for a whole week! While Popo was smoking and steaming like a champion, we dived deeply into the dirty, dark side of geology during this week: We sampled ash and pumice from the four large eruptions of the last 15,000 years. For hard-rock geologists like Chiara, Julie and me, this was a challenging task. So much dust, so few proper minerals! But if you want to understand how Popo works, this is simply what you need to go through.

 

Armed with shovels of various sizes, a tape measure, our geological hammers (you never know!), and, last but not least, a hoe (romantically referred to as the ‘mano de gato’ - ‘the hand of the cat’), we went out onto Popo’s flanks to search and exploit its volcanic deposits. Hugo, the Popo expert, unerringly navigated us to the top spots, where we then got to work. The following series of pictures reveals what this actually involved:

 

El Tronco.jpg

First of all, we need to get an overview about what we see. In this case, we are looking at the deposits of at least three large eruptions of the last 5,000 years. If you want to know more about such eruptions, just ask us!

 

Closeup.jpg

Next, we describe the different layers we see. This includes the size and properties of the clasts, the structures, and the thicknesses of the units.

 

hoe.jpg

After that, we can start sampling. Sometimes it can be straightforward, sometimes you may need a helping mano de gato (‘the hand of the cat’) to clear the sampling site and guarantee a neat sample.

 

digging.jpg

Some or all parts of the layers might be covered with soil or debris. In this case, the shovels of various sizes come into play. This picture demonstrates that in doing so you may excavate more than rocks, such as the rubbish of what apparently was a big Mexican Fiesta (including diapers and mayonnaise).

 

Bomb.jpg

On other occasions, it might not be garbage, but a proper treasure that you dig out: A volcanic bomb! Hard-rock geologists, get your hammers and cameras ready!

 

Pumice.jpg

And this is what you get if you repeat the above steps for a whole week.

 

Now, this might have all been a bit nerdy, so I’ll finish this blog entry with an almost completely unrelated note. Of course we are not only interested in rocks, but also in Mexican culture. Naturally, when a worker in a quarry (we were there by chance, obviously) told us that there was a man in the nearby town San Nicolás de los Ranchos who would craft wonderful molcajetes (pestle and mortars), we went there immediately.

 

On the way there, Hugo explained to us that molcajetes are mortars especially designed for making salsa. Did I mention that they are made of rock? This is also why the salsa made using molcajetes tastes different than if you just use a simple blender – the sauce takes up the taste of the rock.

 

With this salsa-lesson learned, we were all quite keen to see these wonderful items. But how would we find the Molcajete Man in the village? It’s easier than you’d think: you just ask anyone on the street for molcajetes. He/she won’t be able to give you a helpful answer, but 3 minutes later the whole village will know about the lost tourists looking for molcajetes. Out of nowhere, a random girl will appear next to your car, offering to bring you to Molcajete Man. Being a lost tourist, you accept the offer and follow the girl for about 30 minutes through the village, which gives you the opportunity to take some tourist pictures:

 

San Nicolas 2.jpg

San Nicolás de los Ranchos is built on laharic deposits from Popocatépetl.

 

San Nicolas 1.jpg

Evacuation routes are signposted all around Popo.

 

Popoart.jpg

The presence of the volcano inspires local artists to draw their own conclusions on what happens in nature.

 

Finally, we reached the mansion of Molcajete Man. He looked different than I expected, but obviously he is a master of molcajeting.

 

Molcajete Man.jpg

Molcajete Man crafting a molcajete.

 

We would have really loved to get our own molcajete by that time, but these mortars are just way too big to transport to the UK. At least they are if you are already sending a garage full of pumice there.

 

Thus our pumice week has ended, and we enter phase two: rocks! I can already promise you it will be an exciting ride, so visit us again!

0

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.

green-bottle fly.jpg

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.

 

2014-10-16 Gross maggots with adult.jpg   issue2forensic3_large.jpg

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.

 

where do you keep the maggots_resized2.jpg

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

 

puppa&maggots_resized.jpg

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.

picking out pupae_resized.jpg

Daniel sieving out the pupae from the box.

 

Maggots&pupae_resized.jpg

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.

 

 

Fly puppa sorted_resized.jpg

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.

 

where do you keep the maggots_resized.jpg

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!

 

C_vicina-48h.jpgC_vicina-216h.jpg

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.

 

Micro-CT scan of blowfly pupa.jpg

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.

0

Adrian GloverDeep-Sea Systematics and Ecology Group, Department of Life Sciences

Wednesday 28 January 11:00

Sir Neil Chalmers seminar room, Darwin Centre LG16 (below Attenborough studio)


The deep oceans contain a vast and untapped wealth of minerals useful to humans. In geological terms, there is much known with regard the distribution of these minerals at different types of deep-sea environment. The first polymetallic (or manganese) nodules were recovered by the Challenger expedition in 1873, in the deep Atlantic. In the 1960s, the first estimates were made of the total mineral wealth of the oceans, and the first surveys undertaken. In 1978, the first fully integrated mining trials recovered several hundred tonnes of nodules from the central abyssal Pacific at depths of 5500m; in the preceding year, hydrothermal vents were discovered on the Galapagos rift. Since then, an average of 5 hydrothermal vent fields have been discovered every year, and 19 exploration licences for deep-sea minerals in both abyssal nodule and deep-sea vent environments have been issued by the United Naitons International Seabed Authority, 5 of these in 2014 alone. The United Kingdom government is sponsor to 2 exploration licence claims in the central Pacifc covering 267,000 square km, an area larger thant the UK itself.

Despite our accumulated knowledge of the mineral wealth of deep-sea ecosystems, our biological data remains extremely patchy. The central Pacific nodule regions have been well-sampled for nodules, but the majority of species are undescribed and fundamental questions such as the biogeographic distributions of animals unstudied. The diversity and ecological resilience of species to disturbance regimes are largely untested. At hydrothermal vents, critical data such as degrees of endemicity and gene-flow between vent fields is lacking.

The NHM is in a unique position to provide advice to industry and government, as well as academic research, in deep-sea mining from both the geological and environmental point of view. This has potential to be a key area in our Sustainable Futures strategy. In my research group, we have been working with an industrial contractor on the UK-1 deep-sea mining claim in the central Pacific for the last 18 months and are part of an EU FP7 deep-sea mining project. In this talk I will outline some of the history of deep-sea mining, the fundamental science at stake, our role in current projects, the importance of taxonomy, open data and bioinformatics and some of our plans for our forthcoming fieldwork (we sail for a 2-month trip on Feb 12).

 

More information on attending seminars at http://www.nhm.ac.uk/research-curation/news-events/seminars/

0

Large centipedes and larger datasets

 

Dr Greg Edgecombe, Department of Earth Sciences, NHM

 

27th January - 4.00 pm

 

Earth Sciences Seminar Room (Basement, WEB 05, formerly Mineralogy Seminar Room)

                                         

Scolopendromorpha includes the largest and most fiercely predatory centipedes, totalling more than 700 species.  Subjected to phylogenetic analysis since the late 1990s, early studies drew on small sets of external morphological characters, mostly those used in classical taxonomic works.

 

NaturalHistoryMuseum_PictureLibrary_055195_preview.jpg

Scolopendra gigantea

 

In order to bolster the character sample, new anatomical data were worked up by systematically sampling the group’s diversity in order to formulate new characters from understudied structures/organ systems. Simultaneously, targeted sequencing of a few markers for a small (but growing) number of species provided the first molecular estimates of phylogeny.  These have resulted in stable higher-level relationships that predict a single origin of blindness in three lineages that share this trait, and are now backed up by transcriptomic datasets with high gene occupancy. Explicit matrices of morphological characters and fossils coded as terminal taxa remain vital to “total evidence” dating/tip dating of the tree.

 

More information on attending seminars at http://www.nhm.ac.uk/research-curation/news-events/seminars/