Tag: Biology

In the business of dwarf mongooses

Posted on by dan.watts

Leopards, hard-boiled eggs, “yip yip yip”-ping, and faeces collecting – just a typical day in the life of dwarf mongoose field researcher Amy Morris-Drake. 

Having spent a holiday in South Africa before starting her undergraduate degree in Biology at the University of Bristol, Amy Morris-Drake fell in love with the noise and colours of the African bush. At the end of 2013, having graduated, she saw an advert seeking a Research Assistant that required the applicant to go to South Africa and study the behaviour of an adorable tiny mammal entirely unknown to Amy at the time, the dwarf mongoose.  

The dwarf mongoose is the smallest of the three social mongoose species found in Africa, making termite mounds their home. Collectively known as a business, dwarf mongooses measure 18–30cm from head to tail. But despite their size, dwarf mongooses are hardy creatures who work tirelessly – foraging, grooming and defending one another from rival groups and scores of predators. 

Always fascinated by animal behaviour and determined to return to Africa, Amy landed the Research Assistant job in Professor Andy Radford’s Dwarf Mongoose Research Project. She lived on Sorabi Rock Lodge reserve for 6 months, observing the creatures in their natural habitat. “It was originally going to be 3 months but I loved it and didn’t want to leave”, recalls Amy. The dwarf mongooses made such as impression that on her return to the UK, Amy decided to study them for her Masters and then her PhD (which she completed this year). She took a small break in between the Masters and PhD to try something new – observing elephant behaviour, also in South Africa – but that didn’t quite go to plan. “Instead of trying to focus on elephants, I was always scanning termite mounds so my eyes were just tuned in to these mongooses and their lives”. 

At Sorabi, the researchers (normally 4 per year) all share a house, eating and sleeping in close quarters before heading out solo to observe the 8 habituated mongoose groups. Because none of the ‘Big Five’ live on this reserve, students can roam on foot. “There may be the occasional leopard that passes through” Amy mentions casually, “but they’re nocturnal so we’re alright”. In her first few days on the reserve back in 2013, Amy recalls being baffled by fellow researchers at the stove every night boiling eggs, but quickly learned the reason. Habituated mongooses adore eggs, and the promise of a mouthful is enough to get the tiny mammals onto some scales for the students to monitor their weight to observe foraging success and pregnancies. And so, for Amy, every day at the researcher house involved waking up, eating breakfast and mashing last-night’s eggs. 

Dwarf mongooses rise with the sun at around 8 am, or 9 am if it’s a cold day. Amy would venture out to the burrow she tracked her mongoose family to the night before, kitted up with equipment, scales, a GPS, maps and, of course, eggs. She would sit by the mound with a flask of coffee and wait for the mongooses to emerge from their sleeping quarters. After the family finished up with their cuddles and grooming, Amy weighed them, treating them with a tiny piece of egg as a reward for jumping onto the scales. Repeated morning, midday and in the evening, handing over the egg with a “yip yip yip” to vocalise her thanks in mongoose for their cooperation, Amy could build a picture of how different situations affects the weight of individuals. 

The focus of Amy’s PhD was social conflict, including territorial interactions with outsider groups. To simulate the current or recent presence of rival groups, Amy used playback of calls and introduced faeces from rival families to the group and then studied their response. This required collecting hundreds of faecal samples for different experiments. She describes wading through the bushes in gaiters to protect from ticks and thorns, and waiting for the mongooses to do their business, all the while enduring their judgmental stares. In one experiment, Amy stored “outsider” samples and distributed these on cue to the group being studied at the same time every day for a week; in control weeks, she presented herbivore faeces in the same fashion. In total, she managed to complete both trials weeks to 7 of the habituated groups; a feat of perseverance, skill and patience.  

“When working with wild animals, things always go wrong”, she says. Sometimes the group would be preoccupied with sporadic territory-marking or birds of prey flying overhead, instead of reacting to the out-group scents and sounds. Due to certain reactions or conditions not going her way, Amy ultimately had to scrap nearly a month’s worth of data from that particular field season. It’s physically demanding work, with long hours spent alone in 35C heat with insects, invertebrates, and reptiles to contend with. Upon collecting the last few faeces samples, Amy remembers “falling on [her] knees and crying” with relief. But it was worth it: she found that, by the end of the week of rival-group faecal presentations, the test subjects were foraging closer together, grooming and scent-marking more, and putting on less weight, providing the first experimental evidence of cumulative effects of intergroup conflict. 

According to Amy, to be a good experimental biologist you need an incredible amount of patience. In the early stages of her research, Amy would call up the project’s Principal Investigator, Andy Radford, frustrated that she wouldn’t be able to obtain enough behavioural data to complete her Masters. But with practice, she was able to train her eye to spot the mongoose’s subtle movements, expressions, and vocal responses to outgroup threats, and finished her PhD earlier this year. “Fieldwork isn’t for everyone”, Amy notes, “but it’s amazing seeing cool behaviours that you’ve learned about in lectures happen half a metre away from you”. The dwarf mongooses go about their daily lives as if you’re not even there, and Amy had a first-hand view into this cooperatively breeding society. 

Amy visited the reserve every year for 7 years, spending 5 or 6 months out there at a time. She likes to think that the dwarf mongoose families remember her despite the months apart. The mongooses have blatant favourites in the researchers, giving out high-pitched calls to the ones they are most excited to see. Now that Amy has completed her PhD, she continues to work on the theme of outgroup conflict as a postdoc, with 10 years’ worth of mongoose data to sift through to uncover lasting behavioural and fitness impacts. As to the Dwarf Mongoose Research Project, Amy is hopeful that funding will be found so that many other researchers can follow her to Sorabi. One of her most rewarding moments has been to witness the experiences of her fellow scientists on the project as they fall in love with the vibrant beauty of South Africa and the diversity of its animals and landscapes. And the deepest love of all is for the mongooses. Contributors to the project have all stayed in touch, as members of a truly long-term community dedicated to the greater understanding and prosperity of these tiny but fearless creatures. 

Written by: Agatha Hewitt 

Rosie Ford tells her experience as winner of Bristol’s 3 Minute Thesis (3MT) competition

Posted on by jessica.camps

Rosie recently won the University of Bristol’s 3 Minute Thesis (3MT) competition for her talk on ‘Fungal secondary metabolites: exploring a kingdom of possibilities.  Rosie tells us about her experience and some top tips about presenting your research in a virtual world.

3MT® (or Three Minute Thesis) is a competition for doctoral students, originating from the University of Queensland, which stipulates that competitors must present their research in just 3 minutes – any longer and they are immediately disqualified. Normally, the competition is held in person, in front of an audience, but due to COVID-19, in the past two years, the competitions have been moved online, presenting a new challenge – how do you engage an audience who can walk away from their screen at any time?

I decided to take part in Bristol Doctoral College’s 2021 3MT competition for several reasons. The first, to improve my presenting skills, especially in a virtual world I wanted to teach myself how to adapt to this. Secondly, I hadn’t set foot in the lab since December 2020, and I was just about to head back to research after a PIPS placement when I submitted my 3MT application – I needed to refamiliarize myself with my research and what made it so exciting (how better to do this than explaining your project and arguing why it is important in a concise way). Lastly, I’d heard great things from colleagues who had taken part in the Bristol Doctoral College 3MT in the past so why not give it a go myself?

The whole experience was hugely rewarding, and the support is given by the Bristol Doctoral College and the other candidates was key in my success. There were never any feelings of intense competition but rather mutual support and a desire to communicate research in an accessible manner. Potentially winning the competition was simply a bonus to all the skills you picked up along the way. So here are the key things I learnt:

1. Eye contact is crucial – we know that this is true for in-person presentations, you can’t stare at the floor the whole time, but how do you convey this when you’re using a computer or laptop? Look straight into the camera. The temptation is always to look at your audience to see how they are responding to you, as you would normally, but if you are looking at your screen you don’t seem as prepared. Perhaps the easiest way to teach yourself to make eye contact with a virtual audience is to record yourself and watch it back. This also helps you to see what your body language is like and if it adds to or distracts from your talk. Not only this but looking at the camera does actually help with nerves since you can ignore anything else going on in that video call and just focus on presenting.

2. Check your presentation is appropriate for your audience by practising it in front of people in your target group. This could be friends, family, or colleagues, and they don’t have to listen to the whole thing, even just 1 slide or the first 30 seconds would be useful. If you’ve lost them already, you need to rethink things. Even though I was lucky enough to be the winner of this year’s competition, I’m definitely guilty of this too. In my first version of my 3MT talk, the first word I said was “peptide”. Admittedly this was key to my presentation but perhaps not the most exciting way to start off, especially if your audience doesn’t know what a peptide is – something my fellow 3MT competitors pointed out to me. On that note, if you have to include something technical or complex in a presentation to a lay audience, give yourself plenty of time to explain it and metaphors can really help with this – but make sure you use something most people will know (i.e., you shouldn’t need to explain your metaphor too).

I’m looking forward to going onto the next stages of the competition, seeing what other doctoral students across the UK are up to, and picking up some useful skills as I go along.

Rosie Ford, SWBio DTP student

 

Our deep origins: deciphering the earliest branches on the tree of life

Posted on by jessica.camps

Uncovering where we come from and how we have evolved involves a trip into the ancient history of life. Delving deep into our past, we find that the eukaryotic cells that eventually became animals like you and me, branched from other types of cell long ago. But the precise way this branching occurred and the unique features that distinguish our cells from others is uncertain and hotly debated. Studying rocks and specifically fossils has long been the only source of information about these deep origins of life. Unfortunately, the majority of organisms leave little or no trace in the fossil record from which their ancestry can be determined. This is but one of the many challenges scientists face when trying to unravel the origin of eukaryotic cells.

Examples of the three domains of life: the Bacteria Helicobacter pylori, the Archaea Halobacterium sp. strain NRC-1, and a diverse range of Eukaryotes. Images courtesy of Wikipedia.

Phylogenetics is a field that aims to understand the evolutionary relationships between species and is a key tool for deducing the common ancestor that eukaryotes shared with the two other domains of life – the Archaea and Bacteria. In their recent paper that was published in Nature Ecology and Evolution, Williams, Cox, Foster, Szöllősi, and Embley focused on determining which of the two current hypotheses for the structure of the tree of life are most likely to be correct, and attempted to find last common ancestor of the Archaea and Eukarya. One of these hypothesises, the three-domain tree, suggests that the archaea and eukaryotes are ancient sister lineages; the other, the two-domain tree, proposes that eukaryotes evolved from within the archaea. The two-domain tree suggests an endosymbiotic event in which an Archaeon engulfed a Bacterium, which later became the mitochondria of eukaryotes, leading to the evolution of Eukarya and ultimately us. Lead author Tom Williams states that their use of “the best-fitting substitution models” supports the two-domain model.

Schematic phylogenetic trees showing the two competing ideas for where Eukarya sit in the tree of life. Image courtesy of Thomas Gorochowski.

The exact Archaean has yet to be found, but Williams et al. have taken a significant step towards elucidating who this proto eukaryote might be. The paper proposes that the “best candidate for the closest archaeal relative of the eukaryotic nuclear lineage” is a member of the Asgard Archaea, Heimdallarchaeota. The identification of Heimdallarchaeota as the closest sister-group to eukaryotes, means that it shares the most features of any other known archaeal cell with eukaryotes. However, Heimdallarchaeota are not the direct ancestors of eukaryotic cells, only the ones with the closest known phylogenetic relationship. The work of Williams et al. suggests that even closer archaeal relatives of eukaryotes might remain to be found.

When asked for a comment on what the paper means and how he found the process, Williams spoke about how “working out what happened potentially billions of years ago [was] difficult and a number of hypotheses for eukaryotic origins have been discussed recently”. Upon re-evaluation of these claims “our analyses support just one of these ideas: a two-domains tree in which key components of eukaryotic cells evolved from within the archaeal domain.”

So, how is this significant to us? Aside from the direct scientific relevance of this study in understanding the origins of eukaryotes, Williams paints a bigger picture. This is one in which we can see how eukaryotes are distinguished from their archaeal and prokaryotic relatives; fundamentally what makes eukaryotes unique at the lowest level. Furthermore, it highlights how the eukaryotes became so inherently complex. The research into eukaryotic origins is far from finished, but Williams et al. have broadened our understanding of where the types of cells that make up you and I come from and identifies the source of their unique features.

Paper: Phylogenomics provides robust support for a two-domains tree of life (2019) Williams T.A., Cox C.J., Foster P.G., Szollosi G.J. & Embley T.M. (2019) Nature Ecology and Evolution DOI: 10.1038/s41559-019-1040-x

Written by Ellie Nichols (2nd Year Biology BSc)

Ellie Nichols is a second-year biology student interested in molecular genetics and phylogenetics. If you’d like to contact her, she is available at pu18241@bristol.ac.uk