Biology Archives - Page 5 of 7

April 3, 2018April 12, 2018

Letter from Ternate by Prof Donald M Waller

Thinking to respond

Darwin despaired, paused, then shared.

Pressed to Origin.

Charles Darwin first conceived of his theory of evolution by natural selection in the late 1830s and began work in earnest on his “big book” in the 1840s. Yet it was not until he received a letter from Ternate, Indonesia, from the younger naturalist Alfred Russell Wallace in 1858, threatening to rob him of his originality for the idea, that he was pressed into months of intense activity to publish in 1859 an “abstract” of his longer work that appeared as “On the Origin of Species by Means of Natural Selection . . ”

Darwin was thrown into great anguish by Wallace’s letter and request from Wallace to help get it published. He confided in scientist friends who urged him to prepare a parallel brief summary of his own ideas, extracted from his private essay of 1842. They arranged for both papers to be read before the Royal Society. These did not attract much interest, but “On the Origin” certainly did.

Knuckle cracking maths

Knuckle cracking maths:

Synovial bubbles pop

in partial collapse.

The debate over how knuckles cause a popping sound when cracked has lasted for decades. Now, Chandran Suja and Barakat (2018) have created three equations to mathematically model how the sound is produced. The first equation describes variations in pressure inside the joint, the second describes how pressure variations results in bubble size variations, whilst the third equation links the size variation of bubbles with the production of acoustic pressure waves.

When cracking your fingers the joints are pulled apart, the pressure goes down and bubbles appear in the synovial fluid which lubricates the joint. During knuckle cracking the pressure changes within the joint causing the size of the bubbles to fluctuate quickly resulting in the popping sound. The new model reveals that the bubbles don’t need to completely collapse in order to produce the sound, explaining why bubbles are observed following knuckle cracking.

Original research: http://dx.doi.org/10.1038/s41598-018-22664-4

April 3, 2018April 3, 2018

Patches on Venus

Patches on Venus:

Atmosphere harbouring the

conditions for life?

In the hunt for extra-terrestrial life, Venus is rarely considered due to the high surface temperatures (~465 °C) and the intense atmospheric pressure (92 times that on Earth). Yet a new study by Limaye et al (2018) suggests that life off the surface of the planet may be possible since the lower cloud layer harbours conditions suitable for microbial life: water, solutes, ~60 °C and an atmospheric pressure roughly equivalent to Earth.

What’s more, observations of Venus have revealed dark patches in the atmosphere that change shape, size and position over time. These are made up of particles roughly the same size as common Earth bacteria and also absorb light of at a similar spectrum. The changes in patch patterns could therefore be the equivalent of algae blooms.

Venus is thought to have once had water on its surface, potentially for as long as 2 billion years providing enough time for life to evolve. As the surface water evaporated the microorganisms could have been transported to the clouds, in similar ways to how bacteria have been found in the atmosphere of Earth (although on Earth aerial microbes do not appear to remain aloft indefinitely). Life on the second planet from the sun therefore remains a possibility and only further observations and potentially even atmospheric sampling will reveal whether the changing dark patches are indeed patterns of microbial life.

Original research: https://doi.org/10.1089/ast.2017.1783

March 29, 2018March 29, 2018

Egg quality

Low egg quality –

the impact of age. Blocking

proteins slows decline.

As women age their reproductive ability decreases due to declining egg quality. However, research by Templeman et al (2018) suggests that blocking a particular group of proteins may help to slow this decline, potentially extending the reproductive period.

The proteins, known as cathepsin B proteases, are more common in age-degraded oocytes (unfertilised eggs) and appear to be part of the problem of decreasing quality. By blocking the proteins in C. elegans worms oocyte quality was maintained for much longer, regardless of whether the drug was administered at the beginning or part way through the worms’ reproductive period. Whilst it’s not ready for testing with humans, it points the way towards an interesting new approach.

Original research: http://dx.doi.org/10.1016/j.cub.2018.01.052

March 27, 2018March 27, 2018

Crop blighter

Rice blast: crop blighter.

Inhibiting one protein

stops the fungal spread.

Up to 30% of rice crop is destroyed by rice blast every year, causing huge welfare and economic costs. Sakulkoo et al (2018) have found that inhibiting a single protein enzyme in the fungus stops the spread of the blight through a rice plant.

The fungus’s mitogen-activated protein Pmk1 plays a role in suppressing its host’s immune system and controls the ability of the fungus to move from one rice cell to another. By inhibiting Pmk1’s kinase the fungus is trapped within the infected rice cell and is unable to spread and infect the rest of the rice plant. This latest discovery could point the way towards new rice blast control methods, resulting in increased food security and economic development.

Original research: http://dx.doi.org/10.1126/science.aaq0892

March 13, 2018May 20, 2021

Reservoir or predator

African clawed frog –

reservoir or predator

of the fungal blight?

Amphibian populations worldwide are being devastated by a fungal infection (known as chytrid or Bd). As an invasive species and carrier of the fungal infection African clawed frogs are often blamed for the spread of chytrid and the current conservation crisis.

Research by Wilson et al (2018) suggests the story is more complicated than it at first seems though. Field studies in California suggest a 10% level of Bd infection in the frogs, with infected individuals having very low levels of infection. Additionally, larval clawed frogs appear to eat the Bd zoospores and may therefore actually be helping to reduce the negative impact and spread of the fungus. Unfortunately the study also suggests that the frog larvae also eat Daphnia, which are another predator of the Bd zoospores.

This latest research adds to growing evidence suggesting that African clawed frogs may not be as guilty as they seemed at first.

Original research: https://doi.org/10.1371/journal.pone.0191537

Interested in African clawed frogs? Check out these other Xenopus sciku: ‘Clawed frogs indicate‘, ‘Have frog, will travel‘, ‘Fungal culprit‘ and ‘Xenopus enrichment‘.

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