Under the sea, Curaçao, Caribbean. Image: Sancia van der Meij
By Sancia van der Meij, Research Fellow
Biologists often refer to the word “species” when they are talking about the animals or plants that they study, but just what exactly is a species? Defining ‘species’ is actually quite tricky…
A basic definition is based on the work of a German biologist called Ernst Mayr, whose simplified description is “a group of interbreeding populations that are reproductively isolated from other groups”. This is a great starting point, but it is difficult to use when studying animals in the field. Biologists therefore use breeding experiments in laboratories and, increasingly, genetics to help determine what a species is.
How and under which circumstances new species evolve remains an important topic in biology. Quite a lot is known about geographical barriers causing the formation of new and distinct species through evolution – a process known as speciation. Mountains, rivers and ocean currents, for example, can divide populations of single species and in the long run – thousands or millions of years – this isolation can cause different populations to evolve in separate, new species.
Gall Crab inhabiting a small tunnel in an Agaricia coral. Image: G van Moorsel
But a more difficult concept in speciation is how species can evolve in the same geographical area. Together with a colleague, I studied the genetic composition of Opecarcinus hypostegus, a tiny crab species, around 5 mm in size, that only occurs in the Atlantic Ocean. These Gall Crabs are adapted to living in stony corals and often show a clear preference for inhabiting closely related coral species.
Overhang in a Agaricia coral where a gall crab dwells. Image: Sancia van der Meij
We studied over 200 specimens from five different coral species, all collected from the Caribbean island of Curaçao. The results showed that O. hypostegus should be considered a single, valid species. But to our surprise, when we zoomed into the details of the genetic composition of the crab, we noticed small differences in the DNA of the crabs inhabiting the various coral species. With statistical tests we could prove that the variation in DNA was significantly different between the crabs inhabiting these five different Agaricia corals.
Gall crab dwelling in Agaricia coral. Image: Sancia van der Meij
Despite the fact that all the crabs live around the same small Caribbean island, it does appear that we see the very first signs of future speciation in the crab’s DNA. Unfortunately we will not be around to witness the new species as it will likely take several hundreds of thousands of years before the making of these new crab species has neared completion. But how exciting to witness its new beginnings?
It is often said that the final frontier of our exploration of the Earth lies deep in the oceans. Covering 70 per cent of the planet’s surface, the oceans nevertheless remain 95 per cent unexplored, according to the National Oceanic and Atmospheric Administration in the United States. And they know, for they are doing the exploring…
Since 2008, the Okeanos Explorer at the NOAA has been investigating deep water ecosystems and has live-streamed many of its remotely operated vehicle (ROV) dives for scientists and the public to observe. Last year, Okeanos was engaged in an exploration of the Mariana Trench Marine National Monument in the Pacific Ocean. During a single dive at an impressive 4,826 metres, on a muddy bottom at a site nicknamed Twin Peaks, a large shrimp was observed, which the participating scientists did not recognise.
Spotted 4,826m below sea level, in the Mariana Trench Marine National Monument: the shrimp Bathystylodactylus cf. bathyalis
This was an unexpected find. Although there are about 4,000 species of caridean shrimps in the world’s oceans, very few live below 1,000 metres, and fewer than 20 species are known from depths lower than 3,000 metres. Those that do are usually only found as broken specimens, creatures damaged by the trawls which also bring them to the surface.
Photos of the deep-dwelling shrimp were duly sent to two experts: Dr Mary Wicksten at Texas A&M University and Dr Sammy De Grave, head of research here at Oxford University Museum of Natural History. Both immediately recognised the specimen as belonging to the rare genus Bathystylodactylus, which comprises of only three scientifically-described species, which in turn are only known from six specimens, all damaged.
The bristly legs are used in passive filter feeding
The Okeanos team had made something of a discovery, one which was published in the open access journal Zookeys. The posture of the shrimp clearly show it to be a filter-feeding species, with its long, bristly legs facing into the current. This type of feeding behaviour has not been seen in caridean shrimps before.
Surprisingly, although the shrimp was observed at almost 5,000 metres below the surface, it is not the deepest recorded shrimp. That honour goes to a different species, Glyphocrangon atlantica, living in the western Atlantic, which has been trawled from as deep as 6,373 metres. Blurry photographs from 6,890 metres in the Kermadec Trench might indicate that carideans live even deeper still, maybe even as far down as a related group of shrimps called dendrobranchiates, which are known from depths down to 7,703 metres.
These findings show that life of many kinds continues to be discovered in regions of the planet once thought to be completely inhospitable.
Of all the questions that curious children ask about specimens in the Museum, the most frequent by far is ‘Is it real?’. It’s a surprisingly complex question, mixing ideas of authenticity with more basic confusion over whether something is, was, or wasn’t ever alive.
So what do children make of all the weird and wonderful things on display in museums and how does it affect their experiences? Research by psychologist Dr Louise Bunce aims to find out, as she explains here…
If you want to know when dinosaurs roamed the Earth, or how bees extract nectar from a flower, or what meteorites are made of, what would you do to find out? Search the web perhaps? The answers to all these questions, and many more besides, can be found on the internet, so why visit a museum instead to learn about the natural world?
A taxidermy rabbit (Oryctolagus cuniculus), used in the research in the Museum…
Despite the wealth of information available online, the objects in museums continue to captivate visitors and offer something that the internet can’t. There’s something about ‘the real’ that has a certain power. Standing close to, and sometimes even touching, the genuine article – whether that be the head of a Dodo, or a painting by a Dutch Master, or a fossilised dinosaur skeleton – can induce goose bumps in museum visitors. But where does this potent effect come from?
… and a soft toy rabbit. Even younger children know the toy rabbit is not ‘real’.
To begin to look at this question I have studied the importance and understanding of the ‘real’ in children visiting museums. When do children develop an understanding that they are looking at the real thing as opposed to a copy or model?
I conducted research with children visiting the Oxford University Museum of Natural History to see whether they understood that displays are of genuinely real animals, not manufactured models or replicas. And if they think they are models, how does that affect their experience?
The results were quite striking. Most 4- to 5-year-olds believed that the animals on display were not real because they were not moving, or because they were not alive. Consequently their reaction was somewhat dismissive.
A child participating in the research at the Museum
In contrast, most older children, those from the age of around 8 years, said that the animals were real because, for example, they had the real animal’s fur, or other authentic features. These children were also more curious about the animals because they were more likely to ask a question about the displays than children who perceived the specimens as not real.
So if younger children were missing out on the power of the real, I wondered whether there was something we could do to help them. I repeated the experiment but this time introduced children to toy animals and asked them to compare them to the museum animals. Now the majority of 4- to 5-year-olds seemed to gain a sense of awe because they perceived the museum animals as genuinely real in comparison to the toys, which they knew were not real.
These experiments seem to indicate that children do not necessarily perceive museum objects in the same ways as adults, but that we can help to give them meaningful encounters with museum specimens to create an inspiring museum visit. So don’t just Google it – grab the kids, a cuddly toy prop, and get down to the museum – or indeed out into nature – to be inspired by the real.
by Steven Williams, Oxford Brookes University research student
Described by A.G. Butler in 1873 as ‘the most gorgeously coloured spider in this genus’, Gasteracantha scintillans, with its metallic green iridescent abdomen, is the first of my Christmas Spiders.
Spiky and sparkly: Gasteracantha scintillans
The beautiful colour of the abdomen certainly has a very festive feel and it would not be out of place next to a bauble on a Christmas tree; at least not in my house. This species and the other closely-related metallic Thorn Spiders are currently only found on the Solomon Islands.
Christmas Island, in the Indian Ocean, is one of the locations where my second Christmas spider, Austracantha minax, can be found. Although not as striking as the metallic green of Gasteracantha scintillans, the layout of the abdominal spines on this spider almost give it the appearance of a star – perfect for the top of a Christmas tree, no?
Austracantha minax: starry, and found, amongst other places, on Christmas Island
The common name of ‘Christmas Spider’ is attributed to this species because in areas of Western Australia it is associated with the arrival of Christmas as the males reach maturity in mid-December and females in January.
Did you know that there is also an Eastern European folk tale of how tinsel came to be included in Christmas tree decorations? The legend tells of how spiders spun cobwebs on a poor family’s undecorated Christmas tree overnight. In the morning the webs turned to gold and silver and the family never lived in poverty again. So when you put the tinsel on the tree this year you could imagine you are a spider spinning a web!
With that spidery festive thought, have a very Merry Christmas from everyone at the Museum!
Visitors to the Museum often comment on just how many things there are to see here, but in fact only a small percentage of the collection is on public display – less than 0.1%. The remaining 99.9% is held in storage for use in research, teaching and to loan to other museums and universities.
I receive hundreds of enquiries from researchers all over the world who are interested in many aspects of animal biology. In exchange for our information about the skeletons, skins, specimens preserved in fluid, nests, shells and taxidermy here, the Museum gets knowledge from world experts who are publishing new science.
Bramble Shark (Echinorhinus brucus). Image: Illustrations of South Africa / Wikimedia
One such recent enquiry, from researchers Dr Samuel Iglésias and Frederik Mollen, concerned the Bramble or Spinous Shark (Echinorhinus brucus). You may not have heard of the Bramble Shark – it’s an enigmatic bottom-of-the-sea dwelling species – but this is one of the reasons why the researchers are trying to track down all known specimens held in European institutions.
The characteristic brambles of the Spinous Shark, Echinorhinus brucus
Bramble Sharks are so called because of the large thorn-like structures, called dermal denticles, that cover the skin. These sharks are thought to be once common in European waters but are now virtually extinct.
I checked the Museum databases and stores and found 14 Bramble Shark specimens in the collections: one taxidermy specimen; one set of jaws with skin; a section of skin; and 11 fluid-preserved dissections. Unfortunately, as is often the case in older natural history collections, the fluid specimens did not have data associated with them – information such as age, locality, who collected them, what the dissections were or who dissected them.
After passing images and this list of specimens to the researchers they sent through an 1875 paper titled The Brain and Cranial Nerves of Echinorhinosus spinosus with notes on the other viscera by Bruce Clarke and the excellently named Hatchett Jackson. This paper describes the dissection of two specimens at the University of Oxford, one of which was a female collected from Penzance on 15 February 1875.
Armed with this new information I was able to cross-reference this dissection with some of our archives to confirm that most of the dissected specimens actually came from this single female shark collected in 1875, which was dissected and the parts used in illustrations in a technical publication.
Section of skin previously identified as Bramble Shark but now re-identified as from a Porcupine Ray (Urogymnus asperrimus)
Another discovery came while photographing the skin specimen, and comparing it to the other dry specimens. It became clear that the thorns of the skin were very different to the typical Bramble Shark arrangement and it turned out that the skin was in fact from a Porcupine Ray (Urogymnus asperrimus).
The happy ending here is that the researchers now have better information for their publication and these specimens will be put ‘on the map’ in the technical literature for other researchers to access.
Although the Museum collections are effectively one Bramble Shark down (but up one Porcupine Ray skin), we do now have better information about the age, locality, relationship, identification, citation in the literature, and history of some these specimens. This makes them even more useful for research in the future.
Not all enquiries end with such a deeply satisfying result, but it is certainly nice when they do.
This is the second in a short series of articles to accompany the Stone Age Primates temporary display at the Museum, created with the Primate Archaeology group at Oxford University. Here, Dr Tomos Proffitt, Postdoctoral Research Assistant in Primate Archaeology, shows how the use of stone tools by modern primates might connect with our earliest human ancestors.
Over the past five years I have been fortunate enough to work with and study some of the earliest known stone tools, uncovered from archaeological sites at Olduvai Gorge, one of the most famous Palaeolithic archaeological sites on our planet. Olduvai Gorge seemingly appears out of nowhere as you drive down the dirt tracks of the north western slope of the Ngorogoro caldera and national park in Northern Tanzania.
The view from the top of Naibor Soit overlooking Olduvai Gorge. Photo Credit: Tomos Proffitt
It is here that the famous Louis and Mary Leakey uncovered evidence which proved that our evolutionary origins extended not thousands, but millions of years into the past, and over the years the site has provided a wealth of animal and early human, or hominin, fossils as well as tens of thousands of examples of the stone tools they made.
Two million years ago if you were sitting where I was in Olduvai, the most noticeable feature would have been a great lake surrounded by vast floodplains, occupied by a range of herbivorous and carnivorous animals taking advantage of the abundant grass, shrubs and fresh water constantly feeding the lake. It is in this setting that you would have found small groups of our hominin ancestors (Homo habilis) standing upright and walking across the floodplains in search of food.
Lake Ndutu located at the south western end of Olduvai Gorge. Early hominins would have occupied a similar lake environment. Photo Credit: Tomos Proffitt.
As a large part of my research involved closely studying and analysing the stone tools used by the hominins who once lived in this landscape my thoughts turned to how these individuals would have used tools for the different tasks they faced.
Once this hominin group had found a partially eaten carcass, possibly that of a Deinotherium (an extinct ancestor of the modern day elephant), they would have set about trying to make the most of this valuable resource.
By using quartz flakes with extremely sharp cutting edges, made by striking a quartz block with a round hammerstone cobble, they would have been able to cut the small scraps of meat that were still attached to areas of the carcass untouched by other predators, such as lions, hyenas, wild dogs and vultures. The hominins, would, however, also have been very interested in the leg bones because they contained an incredibly nutritious food source than not many other animals could easily get to – the bone marrow.
Examples of quartz anvils used by early hominins at Olduvai Gorge. Photo Credited to Mora and de la Torre, 2005.
After butchering the animal they would have carried the meat and bones back to another group, some of whom had been collecting various nuts and roots and were now busy preparing them to be eaten. They would be cracking open the nuts and pulverising the roots on a large flat quartzite anvil using rounded hammerstones. The group that had just arrived would have used the same tools to carefully open the elephant leg bones to access the marrow inside. A whole range of dynamic food gathering, eating, sharing, learning, teaching, tool making, communicating behaviour was taking place at this location.
Fast forward 2 million years: since that original meal, the site has been repeatedly buried in sand and sediment and eroded by flowing water and the only thing that remains from this location of vibrant activity and of the lives of these hominins are a few fossilised bones and a small collection of fragmented and broken stones. This is the type of material we were excavating in 2015.
Archaeologists use a range of methods to try and understand how stone tools were used and some of the most powerful insights can be gained through observing how stone tools are used today.
Chimpanzees using both a hammerstone and anvil to crack open nuts. Photo Credit: Haslam et al, 2009.
Transport yourself now to a small forest clearing in western Africa, where a group of our closest living relatives, chimpanzees, are quietly sitting underneath a number of nut- and fruit-bearing trees. This group is taking advantage of these important food sources, and is doing so by using stone anvils and stone hammers not too dissimilar from the group of hominins at Olduvai Gorge, two million years earlier.
A hammerstone used by a capuchin, on display in the Museum
But it is possible to directly observe the chimpanzee behaviour, recording how the tools are being made and used, what waste is being produced, the learning processes going on between infant and adult, and the range of social interactions that are happening. This modern primate behaviour represents a valuable window into the types of activities that some of our earliest hominin ancestors may have also undertaken.
The Stone Age Primates exhibit at the Museum showcases these types of stone tools and how they are used by modern primates. By closely studying how our closest living primate ancestors, including chimpanzees, capuchins and macaques, make, use and discard stone tools it is becoming increasingly possible to better understand the dynamic range of early human behaviours behind similar types of hammers and anvils found at Olduvai Gorge and other East African archaeological sites.
The Okeanos team had made something of a discovery, one which was 
More Than A Dodo 
