Biology Archives - Page 6 of 8

March 2, 2018March 2, 2018

When I talk about running

What I remember

when I talk about running:

Stress fading away.

Proponents of exercise have long sung its praises as a way of staying physically healthy, but there is increasing evidence that it has mental health benefits as well. Miller et al (2018) found that exercise (and specifically running) helped reduce the impact of chronic stress on the brain.

The scientists compared stressed and unstressed mice that either had access to a running wheel or not. Mice that were able to exercise mitigated some of the negative impacts of stress, whilst mice that were unable to exercise showed a reduction in the long-term potential of their hippocampal function (the part of the brain responsible for learning and memory).

In honour of World Book Day the poem references Haruki Murakami’s excellent meditation on running and life ‘What I Talk About When I Talk About Running’, which itself was a play on Raymond Carver’s ‘What We Talk About When We Talk About Love’.

Original research: https://doi.org/10.1016/j.nlm.2018.01.008

February 16, 2018February 16, 2018

Foibles of research

Manipulation?

Coercion? Unwanted guests?

Foibles of research.

Academia prides itself on being fair, rational-minded and logical. Yet the practice behind these noble aims is sometimes far from that. A study by Fong & Wilhite (2017) reveals the various manipulations that can take place: from scholars gaining guest authorships on research papers despite contributing nothing to unnecessary reference list padding in an effort to boost citation rate. These instances of misconduct are likely a response to the pressures of an academic career – the demand for high numbers of publications and citation rates.

The survey of approximately 12,000 scholars across 18 disciplines revealed that over 35% of scholars have added an author to a manuscript despite little contribution (with female researchers more likely to add honorary authors than male researchers). 20% of scholars felt someone had been added to one of their grant proposal for no reason. 14% of academics reported being coerced into adding citations to their papers by journals, whilst 40% said they’d padded their reference list to pre-empt any coercion. Whilst changes to aspects of the academic system might help alleviate these issues, it’s likely to be a slow process.

Original research: https://doi.org/10.1371/journal.pone.0187394

February 13, 2018May 10, 2019

Inbreeding Depression by Prof Fred W. Allendorf

More homozygous

brings inbreeding depression.

Cousins should not mate.

Inbreeding (mating between relatives) results in offspring having reduced fitness. This is known as inbreeding depression and is primarily caused by increased homozygosity at loci with harmful recessive alleles. Small populations, where most or all mates are relatively closely related, are particularly vulnerable to inbreeding and inbreeding depression. The effects of inbreeding depression in small populations can accumulate to reduce the population growth rate and increase the probability of extinction (Keller and Waller 2002).

Despite being of interest since Darwin, inbreeding depression remains a crucial area of research in conservation biology, ecology, and evolutionary biology. As global change, habitat destruction, and fragmentation rapidly progress, many natural populations will become smaller and more isolated and consequently more affected by inbreeding depression.

Original Research: Keller, L. F., and D. M. Waller. 2002. Inbreeding effects in wild populations. Trends in Ecology & Evolution 17:230-241. http://dx.doi.org/10.1016/S0169-5347(02)02489-8

Fred W. Allendorf is Regents Professor of Biology Emeritus at the University of Montana. His primary scientific interest is the application of population genetics to conservation biology. He is senior author of the book Conservation and the Genetics of Populations.

Enjoyed this sciku? Check out Fred’s other sciku: Genetic drift, Gene Flow, and Adaptation.

February 6, 2018February 6, 2018

On a knife edge

Life on a knife edge:

The metabolic demands

facing polar bears.

Polar bears rely on marine mammals such as seals which are high-fat prey. Despite the richness of their diet however, new research suggests that a reduction in the prey availability can have severe consequences on polar bear survival.

Pagano et al (2018) monitored nine free-ranging female polar bears over 2 years, measuring their metabolic rates, daily activity patterns, body condition and foraging success. They found that more than half of the bears had an energy deficit resulting from a high metabolic rate (1.6 times higher than previously assumed) and a low intake of the high-fat prey. As fragmentation of sea ice continues and seals become harder to catch the high metabolic requirements of polar bears is likely to become increasingly catastrophic for the species.

Original research: https://doi.org/10.1126/science.aan8677

February 2, 2018February 2, 2018

Bright baubles

Bright baubles – the toys

of our childhood. What dangers

lurk behind your joys?

Toys have to be versatile – they need to be interesting, fun, tough and safe. Plenty of toys are collector’s items, sold in second-hand stores or passed onto the next generation. Yet some plastic toys may have a hidden danger.

Turner (2018) analysed used plastic toys using x-ray fluorescence spectrometry. Hazardous elements, including lead, barium, bromine, cadmium and selenium, were found to be present in many of the toys. Among the worst offenders were Lego bricks from the 1970s which had high levels of cadmium (particularly the colours red and yellow), reflecting manufacturing processes at the time of production. Happily toy production is a lot safer nowadays.

Original research: http://dx.doi.org/10.1021/acs.est.7b04685

January 31, 2018January 28, 2022

Quality of Life at Seven Years Post-Stroke by Dr Michael J. Leach

Old stroke survivor

a life of low quality

yet high quantity.

A stroke, otherwise known as a cerebrovascular accident, is a serious health problem whereby blood flow to the brain is interrupted by a blocked or ruptured blood vessel. A stroke is life threatening and requires emergency medical attention. If an individual survives a stroke, then he or she may live with one or more long-term effects, such as memory loss, hemiplegia (i.e. paralysis on one side of the body), visual impairment, or speech problems. Such long-term effects can negatively impact on a stroke survivor’s quality of life across multiple domains: independent living, social relationships, illness, physical senses, and psychological wellbeing. While quality of life has been well studied in the short term after stroke, few studies have investigated quality of life among long-term stroke survivors.

In original research conducted as part of my Master of Biostatistics degree, I assessed quality of life at seven years post-stroke among people residing in the north-eastern suburbs of Melbourne. The validated Assessment of Quality of Life (AQoL) instrument was used to measure quality of life. In the AQoL instrument, scores range from -0.04 (worse than death) to 0.00 (death equivalent) to 1.00 (optimal). Among 1321 stroke cases with a mean age of 68 years, 413 (31% of stroke cases) were still alive at seven years post-stroke and 328 (79% of survivors) were assessed in my study. Of the 328 long-term stroke survivors assessed, 76 (23%) had very poor quality of life ranging from -0.038 to 0.100. Furthermore, 6% of patients had quality of life that healthy individuals deem worse than death (i.e. ranging from -0.038 to 0.00). The mean quality of life score at seven years post-stroke was 0.51. This score means that, if faced with the prospect of being an average seven-year stroke survivor, a given person in the general population would rather live in full health for half of his or her expected life span.

This research is important in that it highlights the dire need for interventions to improve quality of life in the long-term after stroke. Potentially modifiable factors associated with better quality of life in the long-term after stroke could be targeted to improve the quality of stroke survivors’ lives. In my original research, the potentially modifiable factors associated with better quality of life included lesser handicap and independence in activities of daily living (e.g. indoor mobility, dressing, and shopping). An example of a promising targeted intervention to improve post-stroke quality of life is cognitive training aimed at improving brain function. As cognitive training has been shown to make people more independent in activities of daily living over a five-year period, it is a promising intervention to improve quality of life in the long-term after stroke.

Original research:

Leach MJ, Gall SL, Dewey HM, Macdonell RAL, Thrift AG. Factors associated with quality of life in 7-year survivors of stroke. Journal of Neurology, Neurosurgery & Psychiatry. 2011; 82(12):1365-1371. http://dx.doi.org/10.1136/jnnp.2010.234765

Dr Michael J. Leach is an Australian health researcher, biostatistician, and poet with a PhD in Pharmaco-epidemiology and a passion for health humanities. Examples of his science poems are available online: https://imagesofhealth.wordpress.com/.

If you enjoyed this sciku, check out Michael’s other sciku ‘Drug-Induced Hip Fractures‘, ‘The Psychopharmacological Revolution‘, ‘The Core Correlate of Covid-19 Vaccine Acceptance’, ‘The Early Impacts of COVID-19 on Australian General Practice‘, ‘The Burden of Bushfire Smoke‘, and ‘Australian Science Poetry‘ with science communicator Rachel Rayner.

January 26, 2018July 4, 2019

Sqeamish ossifrage by John Norwood

Delectable mouse

in defiance, stands to face

sqeamish ossifrage

The ossifrage, more commonly known as the bearded vulture, prefers to feed on dead animals, feeding predominantly on the bone marrow as opposed to the meat. It will on occasion kill living animals, with its main prey being tortoises which it drops onto rocks to break them open.

This haiku celebrates a defiant mouse but was inspired by a secondary meaning. In my study of cryptography, I recently de-crypted a challenge with the solution: ‘the magic words are squeamish ossifrage’ which, as it turns out, is a phrase frequently incorporated into the solution of cryptographic puzzles since 1977.

Further reading: The Magic Words Are Squeamish Ossifrage

John Norwood is a Mechanical Engineer working with Carbon, Inc. to revolutionize how things are made. His interests include old houses, yoga, baking, cryptography, and bluegrass music. You can follow him on Twitter under the handle @pryoga

Enjoyed this sciku? Check out some of John’s other work: Universal truth, The answer is none, God may be defined, With enough data, and Rivers cut corners.

January 23, 2018January 23, 2018

Beak trimming distaste

Beak trimming distaste,

yet long beaks lead to poor health.

Best of a bad bunch?

Sometimes it’s better to cause harm for the right reasons rather than allowing worse harm to occur. Egg-laying barn hens typically have their beaks trimmed to reduce pecking damage but this practice results in pain and sensory loss for the birds. As a result the practice of beak trimming is being debated worldwide and some countries have already banned it based on welfare concerns.

Riber and Hinrichsen (2017) compared the welfare of trimmed and non-trimmed flocks of hens across 10 separate farms and across 62 weeks. They found that beak trimming actually resulted in higher conditions of hen plumage, skin and keel bones, as well as decreased mortality. Whilst beak trimming seems distasteful, this evidence suggests that it may be the best option after all.

Original research: https://doi.org/10.3389/fvets.2017.00222

January 19, 2018January 19, 2018

Increase carpet tog

Cold stress avoided

in laboratory mice –

increase carpet tog.

Temperature is an important element of animal care and it’s crucial to ensure that captive animals don’t overheat or suffer cold stress. Laboratory mice are often housed with a floor substrate of wood chips which may be useful in reducing cold stress.

Freymann et al (2017) found that the depth of this floor material influenced mouse physiology. Specifically a deeper wood chip layer resulted in mice with reduced adrenal, liver, kidney and heart weights and an increased tail length. These traits have previously been observed in mice housed under warmer conditions suggesting that the deeper substrate material is acting as an insulator and could be used to reduce cold stress in this captive species.

Original research: https://doi.org/10.1177/0023677217694400

January 16, 2018May 10, 2019

Genetic drift by Prof Fred W. Allendorf

Unavoidable

Time and chance happen to all

Wright, genetic drift.

Genetic drift is one of the primary mechanisms of evolution. It is the change in allele frequencies in a population between generations due to the sampling of individuals that become parents and the random binomial sampling of alleles during meiosis. The theory of genetic drift was primarily developed by Sewall Wright.

Genetic drift causes the loss of genetic variation, and it is more pronounced in small and isolated populations. The ongoing human-caused loss of habitat has brought about the loss of genetic variation in many species throughout the world via genetic drift.

Original research:

Wright, S. 1931. Evolution in Mendelian populations. Genetics 16:97-159. http://www.genetics.org/cgi/reprint/16/2/97

Enjoyed this sciku? Check out Fred’s other sciku: Inbreeding Depression, Gene Flow, and Adaptation.

January 12, 2018August 14, 2018

Underground sound

Listening for sound

whilst deep underground requires

middle ears to hear.

Animals living in different environments will face different auditory challenges. To investigate how environment shapes evolution Koyabu et al (2017) compared middle ear morphology across terrestrial, aquatic and subterranean species from the order eulipotyphla (including hedgehogs, moles and shrews).

They found that a subterranean lifestyle involved adaptations that allow for improved sound transmission at low frequencies and reduced transmission of bone-conducted vibrations. The adaptations observed included “a relatively shorter anterior process of the malleus, an enlarged incus, an enlarged staples footplate and a reduction of the orbicular apophysis”.

Original research: https://doi.org/10.1098/rsos.170608

January 10, 2018May 4, 2018

Equal rights for parasites by Donald A. Windsor

All over the Earth

Equal rights for parasites!

All life forms conserved!

Most of the species on Earth are parasites, so parasites are an
integral part of Earth’s biosphere. Parasites enable ecosystems to
function, mainly by preventing monocultures and generating
biodiversity. Therefore, it certainly seems prudent to conserve
parasites. Admittedly, parasites are not warm, fuzzy attractions and
even horrify most people. Consequently, conserving parasites is an
uphill battle. To cheer on supporters, I came up with the catchy
slogan, “Equal rights for parasites!”

Original research:

Windsor, Donald A. Equal rights for parasites. Perspectives in
Biology and Medicine 1997 Winter; 40(2): 222-229. https://doi.org/10.1353/pbm.1997.0011

Windsor, Donald A. Most of the species on Earth are parasites.
International Journal for Parasitology 1998 Dec; 28(12): 1939-1941. https://doi.org/10.1016/S0020-7519(98)00153-2

Windsor, Donald A. Parasites’ rights gaining ground. Nature 2017 December 21/28; 552(7685): 334. https://doi.org/10.1038/d41586-017-08873-3

Donald A. Windsor, a biologist with a multidisciplinary background, is
fascinated by the enormous impact parasites have on ecosystems. He
retired from industrial pharmaceutical research and development 23
years ago. He is currently affiliated with the Ronin Institute for
Independent Scholarship. His blog is:
http://www.parasitesdominate.blogspot.com/

Enjoyed this sciku? Check out Donald’s other sciku: Native American Dugout Canoe in Central New York.

December 20, 2017December 20, 2017

Transcription by Prof Sridhar Hannenhalli

To express or not

Here now a bit or a lot

That is the question.

Every cell in an organism contains an identical copy of the genome, except for rare somatic mutations, that encodes its entire gene complement. Yet, each of the hundreds of individual cell types in an organism utilizes a well-defined subset of the genes – imagine your neurons expressing genes that are normally expressed in skin cells. Thus the cell, starting from the single-celled embryo, must have a mechanism to control when, and how much of, each gene is expressed. This control is exercised, in large part, at the level of transcription – the process of reading the DNA encoding a gene on the genome and copying it into a messenger RNA (mRNA), which is eventually translated into the final protein product (or otherwise processed into a final RNA product).

Besides controlling normal development and defining the identity of individual cells, the response to a change in environment is also managed at the level of transcription. This was first demonstrated by Jacques Monod and Francois Jacob in their seminal 1961 paper, showing that a group of E. coli genes that encode for proteins required to break down lactose is transcriptionally switched on or off depending on whether the growth medium is rich in lactose or glucose. They went on to win the 1965 Nobel Prize in Physiology or Medicine for their discovery.

Transcriptional control plays a critical role not only in development and environmental response, but also at a longer time scale in mediating evolutionary divergence across species. In their classic 1975 paper, Mary-Claire King and Alan C Wilson, observing very high levels of similarity between several proteins of chimpanzees and humans, concluded that the vast phenotypic differences between the two species could not be explained by such small degree of molecular divergence and are likely to be driven by the changes in the mechanisms controlling the gene transcription.

The role of transcriptional control in dictating natural diversity at multiple natural scales from cells within an organism, individuals within a species, and across species is now well established. This extends even to phenotypic changes associated with all complex diseases, and is underscored by the observation that the vast majority of genotypic signals associated with human diseases reside in non-protein-coding regions of the genome, thus focusing the research efforts in interpreting these signals in the context of transcriptional control.

Original research:

Jacob, F. & Monod, J. (1961) Genetic regulatory mechanisms in the synthesis of proteins. J Mol Biol 3, 318–356. http://biotheory.phys.cwru.edu/phys320/JacobMonod1961.pdf

King, M. C. & Wilson, A. C. (1975) Evolution at two levels in humans and chimpanzees. Science (80) 188, 107–116. https://doi.org/10.1126/science.1090005

Hindorff, L. A. et al. (2009)Potential etiologic and functional implications of genome-wide association loci for human diseases and traits. PNAS 106, 9362–9367. https://doi.org/10.1073/pnas.0903103106

Sridhar Hannenhalli is professor of Cell Biology and Molecular Genetics at the UMD, interested in transcriptional regulation and evolution. He is currently visiting IISc, Bangalore, as a Fulbright scholar. You can follow him on twitter @hannenhalli.

December 18, 2017December 18, 2017

Exploiting blind spots

Tropical clawed frogs –

what you can’t see can’t hurt you.

Exploiting blind spots.

Providing sufficient shelter for animals in captivity is frequently an important method to improve welfare, however cover may limit the ability to observe animals for health checks. Western clawed frogs (or tropical clawed frogs) are a common model organism, kept in high numbers in laboratories around the world, but there is comparatively little empirical evidence for how best to adequately house this species in captivity.

Cooke (2017) found that a black overhead cover was the optimal method of providing refuge for this species. In a second experiment exploiting the frog’s inability to see certain wavelengths the black cover was swapped for a red translucent cover which was found to be just as effective.

Red translucent covers could therefore be an effective method of providing refuge for the animals whilst simultaneously allowing carers to observe and conduct health checks.

Original research: https://doi.org/10.1177/0023677217737798

December 8, 2017December 8, 2017

Packaging signals by Maria White

Packaging signals:

Limiters of gene exchange

in influenza.

Influenza viruses, which have segmented genomes, can exchange genes through a process called reassortment, which can lead to the formation of novel influenza viruses. At the termini of each gene segment are regions called packaging signals, which direct the incorporation of each gene segment into virus particles during assembly.

A recent study by White et al (2017) demonstrated that heterologous packaging signals limit the efficiency of reassortment, but that this phenotype is dependent on the influenza virus gene segment being examined.

Of note, 85% of the reassortant viruses studied packaged a hemagglutinin (HA) segment carrying matched packaging signals relative to the background of the virus. The HA segment is of particular interest from a public health perspective due to its antigenic properties, and these data suggest that HA packaging signals could be an important factor in determining the likelihood that two influenza virus strains will undergo reassortment.

Original research: https://dx.doi.org/10.1128%2FJVI.00195-17

Maria White is a PhD candidate in the Immunology and Molecular Pathogenesis program at Emory University.

December 5, 2017July 18, 2019

Closing the trap by Dr Hortense Le Ferrand

A feather falling –

hungry inert soul wakes up,

snaps, closing the trap.

The Venus flytrap, Dionaea muscipula, is a carnivorous plant that performs one of the fastest movements in the flora: when an insects touches the hairs inside the leaves of the trap, it closes in a few milliseconds.

Inspired by the plants and its internal microstructure, a team of researchers from ETH Zürich and Purdue University have developed a composite material mimicking the Venus leaf and able to change shape as fast as the plant (Schmied & Le Ferrand et al, 2017).

Thanks to the good match between the theoretical simulations and the experimental results, their method opens new avenues for the creation of autonomous and fast robotic devices.

Original research: https://doi.org/10.1088/1748-3190/aa5efd

Dr Hortense Le Ferrand is a postdoctoral fellow at Nanyang Technical University, Singapore. Hortense’s interests are on the fabrication and design of novel materials and systems inspired by nature. Check out her other scku ‘Shrimp molting’ here.

November 24, 2017December 11, 2017

Dark moths by Prof Matthew J. James

Industrial soot

Biston betularia

Quo vadis dark moths?

The Peppered Moth (Biston betularia) is a classic example of evolution in action, yet in recent years Darwin’s Finches seem to have eclipsed the Peppered Moth as the textbook example of natural selection.

This sciku, written by Professor Matthew J. James, celebrates the Peppered Moth as an example of rapid natural selection and asks where the dark moths are going, Quo vadis in Latin meaning “Where are you going?”. The question refers to both the population change in moth colouration from dark to light and also implies a nostalgic deeper meaning asking where the Peppered Moth explanation of natural selection has gone in light of the present-day dominance of Darwin’s Finches.

The wild-type Peppered Moth has light wing patterns that act as effective camouflage against its common environmental background. Industrial smog from 19th century coal burning in the United Kingdom resulted in the trees upon which they rested becoming blackened by soot, making the moths stand out. As a result the population of light-winged moths plummeted due to increased predation, however numbers of the melanic mutant form (black in colour) of the species rose – this process has been termed Industrial Melanism. As the Industrial Revolution waned and levels of pollution decreased, numbers of the light-winged form of the moth rose once again. Cook & Saccheri (2013) present an interesting review of the Peppered Moth as a natural selection case study.

Original research: https://dx.doi.org/10.1038%2Fhdy.2012.92

Professor Matthew J. James is Chair in the Department of Geology at Sonoma State University, California. His recent book, Collecting Evolution, examines a scientific collecting expedition to the Galapagos Islands in 1905-06 that resulted in the concept of Darwin’s Finches being developed by David Lack in his 1947 book by that same name.

November 20, 2017November 20, 2017

Food or family?

Learning to distinguish kin

is hard with prey near.

The benefits of recognising your relatives are many and in cannibalistic species can include avoiding eating members of your own family. Learning kin cues frequently occurs early in life when a number of other cues need to also be learnt, including food cues.

Christiansen and Schausberger (2017) found that predatory mites raised with only their relatives were able to distinguish between related and unrelated larvae. This distinction was not made by mites reared in the presence of relatives and food cues.

The presence of food cues interfered with the learning of kin cues, yet the presence of kin cues did not disrupt the learning of food cues. This suggests that if food is present the mites will learn to identify it, however if there is no food and the mites may need to resort to cannibalism then they learn to avoid eating their own relatives.

Original research: https://doi.org/10.1016/j.anbehav.2017.09.005

November 15, 2017March 25, 2021

A zoo without bars by Dr Lisa Holmes

A zoo without bars –

Building thoughtful habitats

for all to explore.

Chester Zoo (www.chesterzoo.org) is a registered conservation and education charity that supports projects around the world and closer to home in Cheshire. Welcoming 1.9 million visitors a year, it is the most visited zoo in the UK; home to over 15,000 animals and more than 500 different species, many of which are endangered in the wild.

Chester Zoo has continued with the ‘always building’ philosophy of our founder, George Mottershead, who created the UK’s first zoo without bars and focused on animal wellbeing and conservation. In 2015 Chester Zoo opened Islands which was the largest zoological development in the UK to date. The Islands expedition is an immersive experience, taking visitors through six South East Asian islands to discover the incredible wildlife native to those areas and highlight the conservation issues that the zoo staff are working hard to address.

Modern day zoo research encompasses many aspects of biological and social sciences with the overall aim to address challenges faced in the natural world. Chester Zoo not only supports conservation research both in- and ex-situ but leads on important projects both in the UK and across the globe to improve the management of animals and plants, influence sustainability of wild populations and inspire others to Act for Wildlife.

Lisa Holmes is the Behaviour and Welfare Scientist within the Applied Science team at Chester Zoo. Her role involves working closely with the animal curators and keepers to provide evidence-based recommendations to enhance animal wellbeing and help to inform enclosure design. Lisa supervises postgraduate and sandwich placement students who help to gather key data for a wide range of species. Lisa’s research team are currently working on a long-term project assessing the response of species which have moved into the new Islands habitats.

Check out Lisa’s latest sciku ‘The Masterplan’ here.

November 13, 2017November 13, 2017

An orphan crop

Yam: an orphan crop,

vital yet disregarded.

Gene map may assist.

Yams are a stable tuber crop in tropical Africa yet their cultivation has been constrained due to little interest from the rest of the world, their susceptibility to pests and diseases, and their awkward propagation. As such they can be referred to as an “orphan crop that would benefit from crop improvement efforts”.

To help the humble yam’s lot, researchers have sequenced the genome of the white Guinea yam (Tamiru et al, 2017). The research has revealed that yams belong to a unique genus (Dioscorea) that is distinct from rice, palm and banana groups. Yams have separate male and female plants (a limiting factor for yam breeding efforts) but the research has now revealed that yams use female heterogametic sex determination – unlike our XX females and XY males, yams have ZZ males and ZW females meaning that it’s the female gamete that determines the sex of individual offspring. The research hopes to assist yam breeding and cultivation efforts as well as improve food security and sustainability.

Original research: https://doi.org/10.1186/s12915-017-0419-x

November 6, 2017November 6, 2017

Little peepers

Nocturnal Kiwi.

Redundant little peepers –

can survive blindness.

Most birds have excellent vision, even those that are active under low light conditions. In contrast the kiwi has the smallest eyes relative to body mass of any bird and poor vision. In fact, kiwis have been observed surviving in good condition in the wild despite being completely blind (Moore et al, 2017). Kiwis instead have sensitive auditory, olfactory and tactile somatosensory systems which they use to navigate the world and survive.

Original research: https://doi.org/10.1186/s12915-017-0424-0

November 4, 2017November 6, 2017

Swim in step

‘Let’s stick together,’

said the guppy to her friend,

‘we can swim in step.’

Shoaling in fish can provide safety from predators and increase the effectiveness of group movement. This group efficiency can be influenced by the behaviour of individuals within the group and a measure of group coordination is the extent to which animals align with one another – termed polarisation.

Investigating female guppies, Davis et al (2017) found that groups of familiar individuals were more polarised than groups of unfamiliar individuals. This was especially apparent when the groups were in novel surroundings and reduced with habituation to their surroundings. This increased coordination suggests that groups of individuals familiar with one another may be better able to cope with challenging situations.

Original research: https://doi.org/10.1098/rsos.170312

October 30, 2017October 30, 2017

Declining monarchs

Declining monarchs:

Habitat not climate is

your Achilles’ heel.

Understanding why a species is declining is a large part of establishing a suitable conservation approach. In North America the monarch butterfly population has sharply declined in recent decades, yet the reasons for this were unclear until now.

Thogmartin et al (2017) investigated monarch butterfly populations and found that the decline is largely down to habitat loss from herbicide use and the loss of overwinter forest, as well as insecticides. Whilst climate impacts on yearly population size, this is not enough to explain the decreases in monarch butterfly population recorded over recent decades.

Original Research : https://doi.org/10.1098/rsos.170760

October 23, 2017October 23, 2017

Arachnid genome

duplicated long-ago.

Arachnid genome.

Sometimes having two of something is a good thing. Genes are occasionally duplicated and whilst duplications are often lost, they may be retained and may help aid the evolutionary diversification of organisms. Normally only a few genes are duplicated but occasionally duplication can occur on a greater scale.

Schwager et al (2017) sequenced the genome of the common house spider and found evidence that whole genome duplication occurred in the house spider’s distant past. In fact, comparison with the genome of bark scorpions suggests that the duplication event took place in the common ancestor of spiders and scorpions more than 450 million years ago.

Original research: https://doi.org/10.1186/s12915-017-0399-x

October 16, 2017August 9, 2019

Flocks of new markers

Little white sponges,

filtering in mining zones:

Flocks of new markers.

New species are being discovered all the time and even the most innocuous can be important. A new species of sponge has been discovered and recorded by Lim et al (2017) at a depth of 4000m on the abyssal seafloor of the central Pacific Ocean. Morphologic and genetic analysis of the sponges (Plenaster craigi) has revealed they are a new genus, currently placed within the family Stelligeridae.

The region where the sponges are found is rich in polymetallic (metal-rich) nodules and may well be subjected to deep-sea mining. The sponges could be useful indicators of the impacts of such mining efforts – they are abundant on the nodules, are easily identified and are filter-feeders so sensitive to changing conditions.

The Latin name Plenaster is due to the abundance of star-shaped microscleres within their bodies, whilst the species name of craigi is in honour of the Chief Scientist on the expeditions that sampled the species Professor Craig R. Smith of the University of Hawaii.

Original research: http://dx.doi.org/10.1080/14772000.2017.1358218

October 13, 2017October 13, 2017

Tool of the future?

Environmental

DNA: Conservation

tool of the future?

Conservation efforts depend on the knowledge of species distribution patterns and population size estimates in order to know what needs protection and the subsequent impacts of conservation efforts. But there are a number of difficulties association with biodiversity monitoring techniques, including issues to do with correct species identification and invasive methods.

Environmental DNA – “genetic material obtained directly from environmental samples (soil, sediment, water etc.) without any obvious signs of biological source material” – could be a non-invasive and easy to standardise method of biodiversity monitoring. The advances of next-generation sampling technologies has meant individual or multiple species (through DNA metabarcoding) can be detected from such environmental samples quickly and cheaply.

Thomsen and Willerslev (2015) provide a thorough review of the main findings, future potential and limitations of eDNA for biodiversity monitoring and conservation. They document the successes of eDNA so far and discuss pitfalls such as contamination, inhibition, errors, interpretation and problematic reference DNA databases.

October 9, 2017October 9, 2017

Black and white cat-foot

Black and white cat-foot.

Your numbers are rising but

your home shrinks and splits.

The giant panda (whose Latin binomial name literally means black and white cat-foot) is a poster species for animal conservation yet recently the IUCN Red List downgraded the species from endangered to vulnerable based on an increase in adult population since 1988.

Despite this population increase there remains concern for the future of the species. A study by Xu et al (2017) using remote sensing data suggests that both the total amount of available giant panda habitat and the average size of habitat patches (an indication of habitat fragmentation) have decreased substantially. Whilst total area and habitat patch size have shown signs of an recovery since 2001, they still remain below 1988 levels (1.7% and 13.3% lower respectively).

October 6, 2017October 6, 2017

Secretive flatworms

divide coyly in darkness

by three-stage fission.

Freshwater flatworms are able to reproduce asexually by dividing in half – the head and tail pieces then each become a new worm. This process of binary fission was previously difficult to study as it occurred in darkness, halts with any disturbance and occurs infrequently (about once a month) but researchers now have more of an understanding of how the process occurs.

Malinowski et al (2017) found that fission occurs in three steps: 1) a local constriction along the body of the flatworm as if a waist is forming, 2) pulsations that apply stress to the ‘waist’ ultimately leading to 3) a rupture at the waist and the creation of two pieces which then re-grow their missing halves. The researchers also developed a linear mechanical model of the fission enabling a better understanding of the division process and accurate predictions of where on the body of a flatworm it will occur.