ISSUE 16
In this issue, we delve into the many mysteries of TIME
In this issue, we examine the science behind our favorite Films and TV Series.
ARTWORK: JACK WOOD
CONTENTS THE SATNAV TEAM: Chair Ellen Johnson
EXJ619@student.bham.ac.uk
Co-Chair Isabelle Hayden
ILH600@student.bham.ac.uk
Treasurer Emily Hayward
ECH620@student.bham.ac.uk
Secretary Claire Fletcher
CXF717 @student.bham.ac.uk
Layout Editors Luke Kurowski-Ford
LSK709@student.bham.ac.uk Courtney Kousser CAK500@student.bham.ac.uk
Life Sciences Editor Farhana Alam
FXA576@student.bham.ac.uk
Physical Sciences Editor Marriyum Hasany SMH656@student.bham.ac.uk Copy Editor Isabelle Hayden
ILH600@student.bham.ac.uk
Publicity Officer Abigail Joyce
AXJ830@student.bham.ac.uk
Website Manager Cameron Scott
CXS792@student.bham.ac.uk Front cover artwork by Yujing Yang Rear cover artwork by Jack Wood
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ARTICLES
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A matter of time Nicholas Folidis Taking evolution into our own hands Sean O'Brien Bees: it is our time to help them Nicole Rosik The cost of immortality Abigail Joyce Perovskites: it's your time to shine Marriyum Hasany Ancient evolution: How Neanderthal DNA influenced humanity Courtney Kousser History is repeating itself for Birmingham's theoretical physicists Chris Oliver Legal rights to DNA have yet to keep up with the times Tiffany Idle Causal wizards and Deloreans Callum Gill Rhythm, interrupted: How modern society disrupts our body clock Farhana Alam Oblivion: The death of the Universe Patrick Regan Why must we follow time's arrow? Luke Kurowski-Ford Hanging around: Why do sloths move so slowly? Adam Dorey Saving our future: Learning from the dinosaurs Mia Wroe
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A matter of time Time; it rules our lives and we all experience it on a daily basis. A moment in time often goes so fast that we almost miss it but every now and then it can feel as an eternity. Time has been a matter of debate and fascination among scientists for years. Albert Einstein believed that time is a relative concept and is not as constant as everybody thinks. According to him, the notions of past, present and future are nothing more than a stubborn illusion. Einstein fused time and space together to create a four-dimensional continuum called spacetime, in which every event that has happened or will ever happen, since the beginning of the Universe, already exists and as a result we are all travelling through time and space and experiencing all these different events as they
"...the Wheeler-DeWitt equation tells us that nothing ever happens in the Universe. The Universe itselfis determined by a set of laws that are absolute and do not change with time." occur. Therefore, reality and the flow of time is a result of all the individual moments, an array of “nows”, we live in as we process them from our subjective viewpoint within spacetime. But what is time and, for that matter, what is reality? There are two contradicting theories to explain reality. Quantum mechanics describes the world of subatomic
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1967
John Wheeler and Bruce Dewitt for Wheeler Dewitt equation, unifying gravity and quantum mechanics without including time
Nicholas Folidis explores The Quantum Conundrum of the WheelerDeWitt Equation
particles and all smallscale events whilst general relativity describes the whole Universe and all cosmological events. Physicists, including Einstein, have tried for years to combine these two theories together to create a so called “theory of everything”; a unified field theory that would explain all small and large scale events within our Universe. In the mid-1960s, John Wheeler and Bryce DeWitt took a step towards creating a quantum gravity theory by successfully, mathematically describing the previously uncombined ideas of gravity and quantum mechanics in one, quite complicated, field equation that we now call the Wheeler-DeWitt equation. In their effort to solve one problem, Wheeler and DeWitt introduced an even bigger one, the so-called ‘problem of time’. In their field equation, the quantity of time simply does not exist. In effect, the Wheeler-DeWitt equation tells us that nothing ever happens in the Universe. The Universe itself is determined by a set of laws that are absolute and do not change with time. Put simply, the quantum state of the
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2013 Marco Genovese's team experimentally support Page and Wootter's theory by creating a toy universe and showing that it evolves with time for an internal observer, but not an external one
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Don Page and William Wootters propose that time is a phenomenon that emerges from quantum entanglement
1983 Universe is forever frozen. That mind-boggling prediction is Marco Genovese’s team in Turin, Italy, performed an at odds with every observational evidence we have ever experiment in 2013 that supported Page and Wootters’ collected. Many scientists disagree with the mathematical theory. The team created a toy Universe consisting of just a computation of the cosmos that the Wheeler-DeWitt pair of entangled, polarised photons. In short, the observer equation provides, but nobody was able to prove it wrong. can measure the evolution of the system in one of two ways. That changed in 1983 when theoretical physicists Don The first way is by treating photon A as an internal clock Page and William Wootters came up with a solution on the –due to its ability to alternate between horizontal and quantum conundrum of time. Time then, according to that idea, is an vertical polarisation– and trying to Their novel proposal is based emergent phenomenon that exists due to measure its difference in on the quantum entanglement the quantum entanglement and can only polarisation, thereby becoming phenomenon. According to with it, and compare its exist for observers within our Universe. entangled quantum entanglement, it is polarity with that of photon B. The possible for two particles to exist in a way that the quantum second way is by acting as an external observer, using a clock state of one particle cannot be described independently of completely independent of the two photons, and comparing the state of the other, even when they are spatially separated. their properties as a whole against that external clock. Page and Wootters showed mathematically that an As Page and Wootters predicted, in the first instance, the entangled pair of particles evolve in a way that can serve as a polarisation of photon B varies with time, while in the clock, since measuring the properties of one will change second instance time does not emerge, as there is no those of the other particle. This change gives the illusion of observable change in the system. time. Hypothetically if a clock, entirely independent of our The Page-Wootters mechanism proves that the WheelerUniverse could exist, an external ‘god-like’ observer would DeWitt ‘problem of time’ goes away when viewed through not be able to observe any change. For them the Universe the lens of entanglement and that quantum mechanics and would appear completely static and unchanging, just as the general relativity are not that incompatible after all, giving Wheeler-DeWitt equation predicted. Time then, according hope for a unified theory. Scaling up the experiment and to that idea, is an emergent phenomenon that exists due to trying to prove the idea at a macroscopic scale would be the the quantum entanglement and can only exist for observers next challenge we have to tackle. within our Universe. Only time will tell…
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Taking evolution into our own hands Sean O'Brien explores the research that earned the 2018 Nobel Prize in Chemistry and its implications for the future.
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fter another full earth rotation around the sun, the Royal Swedish Academy of Sciences announced this year’s Nobel Prize Laureates in Chemistry. On 3rd October 2018, the winners were revealed as Frances H. Arnold, for “directed evolution of enzymes”, and George P. Smith and Sir Gregory P. Winter, for “phage display of antibodies”. This article focuses on the ground-breaking research carried out by these scientists, along with applications and potential for the future. Proteins are widely regarded as fundamental to biological systems. One of their most important roles is to function as enzymes, which act as catalysts to speed up reactions. To further understand this research, one must first understand how evolution comes into play. Darwin’s theory of natural selection describes evolution as natural and random. Arnold, Smith and Winter have steered this process into a carefully calculated one, in which evolution is directed, thereby eliminating the randomness and lengthy time scale by which it would occur by natural selection. Improving chemical synthesis by optimising natural products is the end goal. The research led by Frances H. Arnold, which earned half of this year’s Nobel Prize in Chemistry, involved the directed evolution of enzymes to broaden the capacities of chemical synthesis. This process begins with the introduction of random mutations in
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the DNA sequence encoding the enzyme. This will cause restructuring of the amino acids that make up the enzyme structure. The randomly mutated genes are then inserted into bacteria to produce large quantities of these new, altered enzymes. The final stage involves selecting the most efficient enzymes for catalysing the reaction of interest. These selected enzymes can then be made even more efficient through further rounds of this process. This can bring benefits to a wide range of industries, such as production of biofuels or pharmaceuticals. The second half of the Nobel Prize was shared between George P. Smith and Sir Gregory P. Winter, for the evolution of antibodies to fight against autoimmune diseases. Antibodies are large protein molecules composed of four peptide chains, which makes them challenging to produce in large quantities within a laboratory
produce the final antibodies. To produce large quantities of a desired antibody, the phages are allowed to infect bacteria with their packaged DNA, like a Trojan horse, so that the bacteria will now manufacture the antibody. Sir Gregory P. Winter took the phage display method further, using it for the directed evolution of antibodies. Antibodies displayed on the surfaces of phages are tested for how well they bind to their specific target antigen (the unique protein to which an antibody binds). Potential antibodies go through three stages of optimisation, and between each stage the genes encoding the antibodies are randomly mutated. After each stage, the antibodies are refined and become increasingly more effective at binding to their target. This higher binding affinity of antibodies means that lower doses can be used when treating patients, which both saves money and reduces the severity of any side effects. The phage display method is now widely used in the pharmaceutical industry to "...we have taken a process that can take aeons to occur in nature and sped produce drugs capable of combatting autoimmune it up for the benefit ofour species." diseases, such as environment. George P. Smith rheumatoid arthritis. developed a method called ‘phage The research described here display’ where the DNA encoding a illustrates that we, as humans, have protein of interest is packaged into a taken a process that can take aeons to phage (a virus that can only infect occur in nature and sped it up for the bacteria) in a way that results in the benefit of our species. Living in a world protein being expressed on the surface where there is constant fear over the of the phage. Therefore, the phages are destiny of humanity, perhaps it is nice essentially protein capsules, or shells, to hear that our future is not entirely holding the DNA code required to out of our hands.
IMAGE: NOBEL PRIZE COIN
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Bees: it is our time to help them Nicole Rosik highlights the importance of bees and warns of the consequences if we do not help to recover bee populations.
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t’s a sunny Sunday morning; you get out of your bed agriculture and climate change. Bees, just like humans, can and look at all the beautiful nature outside. Then you get sick; they suffer from infections such as Varroa destructor have some porridge with honey and your (a parasitic mite) or Nosema ceranae (a parasitic fungus). favourite fruit. We all enjoy this feeling, Their immune systems are affected by chemicals used in but the majority of people give little agriculture, which means that they get sick more thought towards the origin of their easily and die faster. Herbicides, pesticides and food products. In many cases, this insecticides are the main threats, but destructive involves the humble honeybee. practices used in harvesting also result in a decreased Bees play a crucial role in ability for bees to create nests. Insecticides are widely used in agriculture and everyday the environment and have many detrimental effects on life, as they pollinate crop bees, such as delaying maturity, and causing problems with plants and many wild plants. navigation, learning and recognition of flowers and nests. Bees have a massive influence on the production of our Last but not least is climate change. Increasing temperatures, food and the biodiversity of plants; a third of all food changing patterns of rainfall and extreme weather products depend on bees. According to a Greenpeace report, conditions, such as tsunamis, earthquakes or tornadoes affect there has been a 40% loss of commercial honeybees in the the mortality of our most valuable pollinators. USA since 2006, a 25% loss in Europe since 1985, and a 45% In agriculture, the main way to prevent bees from dying is loss in the UK since 2010. If we continue to neglect bee to transform the current methods of harvesting, by getting populations, the lack of food will "Bees have been helping us for hundreds rid of destructive and chemically bring considerable consequences, intensive systems, and stopping ofyears; it is our time to help them." both economic and practical. A the use of pesticides and third of crops would have to be pollinated by other insects insecticides. There are also plenty of actions that can be taken and the productivity of up to 75% of crops would be by individuals, such as ourselves. A few of these include: most decreased. Due to unsustainable harvesting and substantial importantly, do not use pesticides or herbicides in your own food wastage in recent years, the demand for bees is greater garden; buy products from reliable sources that use than their supply, which suggests that we will face limitations sustainable farming practices; and to pollination in the very near future. Following basic plant some flowers and herbs that economics, limited pollination would mean fewer beewill attract bees, for example, lavender dependent products, such as apples, strawberries or tomatoes, or mint. which would greatly inflate their prices as a consequence. Bees have been helping us for There are many factors that influence the mortality of hundreds of years; it is our time bees but the main ones are diseases, industrial to help them.
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The cost of immortality Abigail Joyce discusses the ethical issues surrounding HeLa cells, the firstimmortalised cell line to be used in scientific research.
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he field of bioethics in science is a tentative subject. There are currently many ethical discussions concerning the morality of using human tissue biopsies in scientific and medical research, and the role of consent in the obtaining of cell samples. Much of this discussion arose from the controversial case of Henrietta Lacks. Born on 1st August 1920, Henrietta Lacks was an AfricanAmerican woman who was diagnosed with aggressive cervical cancer at the age of 30, dying from her tumour around 9 months later, on 4th October 1951. During her extensive and painfully damaging radiation treatment, a sample of her cancerous cells was taken by doctors. The biopsy of cells taken from her tumour was sent from Johns Hopkins hospital to local scientist George Gey, who upon propagating the cancerous cells realised that they showed no signs of ageing or “senescence� that cells usually undergo during replication. They continued to replicate and divide without regulation. As a result of this, HeLa cells (named according to Henrietta’s first and last name) were widely distributed and used in countless branches of science, from the development of the polio vaccine, to the investigation of cell replication and ageing, to genetics, cancer research, and understanding disease and viral infection. The development of the polio vaccine alone has prevented 650,000 deaths and 13 million cases of paralysis since 1988, and HeLa cells have undoubtedly acted as a catalyst in modern medicine. The ethical issues that arose predominantly stemmed from the lack of consent provided by Henrietta or her family members for the use of her biopsied tissue for anything other than diagnosis.
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The Lacks family was given no form of compensation or information, despite the use of their relative’s cells in countless scientific discoveries and in benefitting the reputation and wealth of hundreds of scientists and pharmaceutical companies. Her name was not released publicly and her family was not informed of the cells’ existence until the 1970s, almost two decades after her cells had been taken. Many argue that more compensation should have been given to her family due to the extensive use of her cells. The Lacks family was highly religious, from a poorly educated background and did not understand or agree with the idea of their ancestor’s cells being traded and bartered between research institutes and scientists. They believed strongly that the cells were Henrietta’s “resurrection body” and they were a means for her to return to earth and help humankind, even analogising the resurrection of Jesus by quoting John 11:25; “Those who believe in me will live, even "was the suffering of though they die; and those Henrietta and the who live and believe in me ignorance shown towards will never die.” From a her family a justifiable religious perspective, the price to pay for the maintenance of cells thousands oflives saved, outside of the body of the or prolonged, by the use deceased could be ofthe immortal HeLa cell considered a form of lines?" immortality, and therefore the distribution of these cells without permission from the deceased or their family is seen as disrespectful and a violation of that person’s being. The case of Henrietta Lacks’ cells has led to prominent changes in scientific legislation. Under the Human Tissue Act of 2004, cell lines in the UK are now anonymised and consent is required for the use of human cells in research, and in 2013, an agreement was announced between the Lacks family and the National Institutes of Health to give Henrietta’s family more control over access to their ancestor’s DNA sequence. Complex arguments have arisen from this case: was the suffering of Henrietta and the ignorance shown towards her family a justifiable price to pay for the thousands of lives saved, or prolonged, by the use of the immortal HeLa cell lines?
IMAGES: HENRIETTA LACKS, CROWN BOOKS MICROSCOPIC IMAGE OF HELA CELLS, PAUL ANASTASIADIS, FRAUNHOFER INSTITUTE FOR BIOMEDICAL ENGINEERING
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Perovskites: It’s your time to shine Marriyum Hasany unravels the potential of perovskite solar cells featuring an interview with Cambridge’s Dr. Sam Stranks
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O
ne of the perks of being a part of EPS at the University of Birmingham is the exposure to brilliant minds with exciting ideas on how to use Science and Technology to improve the world. The evening of the 16th of October was no exception, as a Poynting building lecture theatre was filled with intrigued physicists and chemists awaiting a lecture by Dr Sam Stranks on ‘The Future of Perovskites for Solar Power and Lighting’. Introduced by Professor Martin Freer—the head of the School of Physics and Astronomy—Dr Stranks’ incredible career led him to be awarded the 2012 Institute of Physics Roy Thesis Prize for his PhD thesis, followed by a postdoctoral position at the University of Oxford. Currently, he is a Royal Society Research Fellow and the group leader of StranksLab, at the University of Cambridge, which focuses on semiconductors. Dr Strank’s lecture gave an insight into current research being conducted on perovskite solar cells and their potential to be used as a more effective source of power than the crystalline silicon solar cells, which are presently the commercial norm. The current
system in place for the generation of solar power lacks the efficiency and cost-effectiveness required to realistically be considered as a main source of power worldwide. That is where perovskites come in! Perovskites have not only proven to be more efficient, cheaper and versatile but would also be easy to transport due to their general thickness of just 500 nm, making them incredibly lightweight.
anions within the structure can be occupied by various atoms and molecules, allowing perovskites to take on a wide variety of properties depending on the combinations of cations and anions used. This variability allowed a team in Tokyo lead by A. Kojima in 2009, to synthesise perovskite nanocrystals made of organic-inorganic materials, with the capability to absorb and convert light energy into "there was [suddenly] a lot ofexcitement power, with lower than and it was a new space; there was no 4% efficiency. textbook or any other paper you could Fast forward to today refer to...it was very exciting and it’s and this conversion probably the time that transformed my efficiency has increased view on science and my career. to as high as 21%. The They can also be placed on top of perovskite solar cell is contained current silicon crystalline solar cells to within a simple system of a three work synergistically. layered, electrode-perovskite-electrode Perovskites are a class of material cell; this cuts down on power losses composed of a crystal structure caused by too many interfaces within (arrangement of the different atoms the system, and having a continuous within a structure) closely resembling crystalline structure rather than a that of the naturally occurring mineral, porous structure. The most advanced calcium titanite (CaTiO3), as pictured perovskite cells being tested are made in Figure 1. The sites of the cations and from methylammonium, formamidinium, caesium and lead cations, and iodide and bromide anions, which give them the highest stability and performance. Yet,
Cation A Cation B Anion Figure 1
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somehow, they are still relatively easy to prepare. Varying the ratio and the types of different anions present in the perovskites can determine the colour of the cell, and therefore the wavelength of light they can absorb. This may mean that colourful perovskite solar cells could be placed on buildings to not only generate electricity, but to give buildings like the Muirhead Tower the opportunity to serve an aesthetic purpose within the University of Birmingham’s skyline. Another potential application of perovskites is their capability to act as light emitting diodes (LEDs). LEDs are semiconductors that emit light when a current is passed through them, as the electrons from the current fall into “electron holes” within the LED, losing energy as they do so. This lost energy is released as photons of light. Perovskites are also able to accommodate electrons in this way; however, this technology comes with its fair share of challenges. The second part of the lecture mainly focused on the challenges that keep these materials from being used on a commercial scale; the two main areas being the loss of power due to defects within the solar cells, and the movement of ions leading to decomposition of the solar cells, thus significantly reducing their efficiency. However, research is currently underway at full force to combat these issues. After the lecture, I had the wonderful opportunity to briefly speak to Dr Stranks. I voiced my concern about the presence of lead in the perovskite cells, to which Dr Stranks assured me that “while we are searching for lead-free
absorbers, it’s probably not an issue because the amount oflead is very small, so, ifthe entire panel washed off, it would still be below the safe levels of lead… and to put it in context, a silicon panel solder probably has more lead than the perovskite solar cells do.” I asked him about the feasibility of transporting perovskite solar cells to remote communities throughout the world, with frequent power outages, to which he gave me a very hopeful answer: “you could easily put them in
spools ofrolls and carry them in like that… you could fit them easily on a truck or a plane because the weight is significantly less [than silicon solar panels].” Following that, I inquired about the challenges of upscaling the technology, to which he replied, “we know
from many other solid technologies that when you 12 | SATNAV | November 2018
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take it over a larger area, the efficiency drops. [This is because] when you have a larger area you’re more likely to have defective regions in the area, which is partly a deposition challenge, but there’s no reason we couldn’t make it more uniform over a larger area, so there’s work being done on that. The other issue is that when you connect different modules, there are electrical losses… Considering silicon solar cells, the record is 27% but most modules operate at about 15–20% maximum even at the best technology.” A very interesting question put forward by one of my fellow Chemistry students, Harry Fell, concerned how exactly the researchers begin to identify the cations that should be utilised. Dr Stranks told me that “at least with
the 3-D perovskites, it is more limited because it’s a very small site, so you can only fit small molecules, and typically they are best when they are nitrogen or sulphur-rich. There is a bit more leeway with 2-D long chain, and there is a lot ofwork out there looking at cations… There are some that are working well in the community, but in principle you could screen through many molecules, which is probably a very tedious task.”
Relating to our theme of time, I asked Dr Stranks about a time in his research that had the biggest impact in his life. After thinking about it for a few seconds he said, “I
think moving into the perovskite space since 2012, because it was completely unexplored, and the community did not know much about this material… It was serendipitous that I joined in at that time because there was [suddenly] a lot ofexcitement and it was a new space; there was no textbook or any other paper you could refer to, to check ifyou were right. So, it was very exciting and it’s probably the time that transformed my view on science and my career." With that being my last question, the night was concluded. However, the research continues, and the prospect of commercialisation of perovskite solar cells carries light and hope for the future. With the potential to cheaply power houses, and easily be transported and installed in rural areas, this much-needed sustainable source of energy could allow underdeveloped areas to thrive; with the added bonus of looking beautiful at the same time. Perovskite solar cells could be a means of averting climate catastrophe; perhaps we are not heading for dark days after all!
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Ancient evolution: How Neanderthal DNA influenced humanity Courtney Kousser travels back in evolutionary time to explore the relationships between humans and Neanderthals.
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he origin of human life remains a mystery. Echoes of the past reverberate within modern human DNA, reminiscent of the paths taken by ancestral humans. Tens of thousands of years ago, Homo sapiens were just one of several hominid species, which included
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Neanderthals, Denisovans, and the tiny Homo floresiensis (nicknamed “the Little Lady of Flores” and “the Hobbit”). They all appeared to co-exist at some point in history and whispers of their existence and their impact on contemporary life remains imprinted within the human genome.
Modern humans left Africa some 60,000 years ago, with one group heading East and the other migrating West, toward Europe. There they met Neanderthals, another species of “great ape” that left Africa about 150,000 years earlier. The two species began interbreeding, and today most people of
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non-African descent are between 1–5% linked to the presence of Neanderthal On a positive note, Neanderthal, based on genetic DNA, such as blood clotting disorders, humans inherited key sequencing. This finding dashed cardiovascular disease, and Crohn’s aspects of the innate previous assumptions that Homo disease. There is a gene of immune system from sapiens and Homo neanderthalensis Neanderthal origin that results Neanderthals, did not interbreed. in a 25–50% increased risk of including a cluster Nearly half of Neanderthal genes developing Type II diabetes. of genes found within modern human DNA Ancestral Homo sapiens also (specifically, Tollinfluence hair colour and skin acquired sexually transmitted diseases, like receptors 1, 6, and 10) pigmentation, with specific genes specifically human papillomavirus that are essential for fighting invading associated with increased susceptibility (HPV), from interbreeding with microorganisms. Acquiring these genes to sunburn and Neanderthals. likely played an important role in "Who we are today is influenced by Infectious lower ability to quickly adapting to new environmental where, and with whom, our tan. This makes diseases were challenges as ancestral Homo sapiens ancestors have been." sense, as traded, as migrated. However, these genes are also Neanderthals Homo sapiens partly responsible for the over-activity evolved in Europe with lower sunpassed along herpes virus, tapeworms, of immune responses, leading to hayexposure; here, paler skin allowed for tuberculosis, and Helicobacter pylori fever and other allergies. enhanced vitamin D synthesis. (the bacterium causing stomach ulcers) Interestingly, couplings between Neanderthal genes are also correlated to the Neanderthals. While these Neanderthals and Homo sapiens seem with a variety of hair colours, mainly associations are fascinating, it is to have always resulted in less fertile, or light hair, but are never associated with important to note that the presence of even sterile males. Neanderthal genes red hair, making this a uniquely human Neanderthal genes does not necessarily were originally passed through the characteristic. mean a person will develop these female lineage only, and no Some Neanderthal genes are diseases. There are thousands of factors Neanderthal genes are ever found in associated with sleeping male testes or on the X-chromosome. Denisovans ~640,000 years patterns, influencing people This highlights that while breeding ago who prefer to stay between these species occurred, awake late, have dayWestern Neanderthals the relationships “were at the edge ~800,000 time naps and are of biological compatibility,” as years ago even linked to described by David Reich from Eastern Neanderthals Harvard Medical School. narcolepsy. There is also a strong Humans are truly a melting correlation with depression and pot, with ancestral Homo sapiens mood disorders. Like skin and hair migrating around the Modern Human Ancestors pigmentation, sleeping schedules world, absorbing other and mood disorders are associated hominid communities and with sunlight and circadian possibly playing a role in their demise. rhythms, further highlighting the influencing whether a particular gene is Who we are today is influenced by influence of climate in Neanderthal expressed, and there are countless other where, and with whom, our ancestors evolution. Certain physical diseases are causes of these diseases. have been.
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History is repeating itself for Birmingham’s theoretical physicists Chris Oliver discusses the current research on topological phases of matter, as it was once does in the 1970s
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s any regular visitor to the University train station will know, the Nobel Prize in Physics 2016 was jointly won by David J. Thouless, John M. Kosterlitz and F. Duncan Haldane. Kosterlitz and Thouless worked in the Theoretical Physics Group in the School of Physics and Astronomy here at Birmingham during the 1970s, when they completed the work that would make them Nobel laureates. Now
"...light moving in these exotic states ofmatter can just ‘dodge’ impurities and defects and keep moving to produce a nice, clear image."
properties. Nowadays, topological phases are back at Birmingham in a new form: topological photonics. Here, scientists are looking for the same unusual behaviour but for systems made of light instead of electrons. Why are scientists so excited by this new research? The reason is that light and electrons generally have very different properties, so making them behave in the same way and describing them both using the same theoretical ideas is no mean feat. Scientists have therefore learnt a lot from applying these old ideas about electrons to a different area. Learning new things about the natural world is, after all, the
history is repeating itself, with that same research group starting work in this field again. But what is this award-winning subject all about, and why does it matter? The 2016 Nobel Prize was awarded for research into so-called topological phases of matter. These are "...research at Birmingham has come exotic states of matter that full circle, from the fundamentals of can exist at very low topological phases to applications temperatures, where the in new areas." electrons in the system show very unusual behaviour, compared to fundamental role of scientists. familiar solids, liquids and gases. This research has more practical Graphene, another Nobel-winning benefits for scientists too. Electrons in subject with lots of important graphene move over distances in the applications, is an example of a nanometer range, but the light-based material that can display these strange systems built by the scientists are
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microns in size – this means they are 1000 times larger and therefore 1000 times easier to work with. Now, the experimental observation of topological behaviour in electrons is becoming much more straightforward as it is being modelled after the topological behaviour of light. One of the most fascinating properties of topological phases could save scientists all this work. It turns out that light moving in these exotic states of matter can just ‘dodge’ impurities and defects and keep moving to produce a nice, clear image. But perhaps the most exciting aspect of this research is the amazing applications that might come about from this discovery. At the moment, optical devices have huge amounts of money and time being spent on them to make sure they are manufactured in a sterile environment. This means making them in carefully controlled clean rooms to make sure that no impurities get trapped inside the glass and distort the image. So, after four decades, theoretical physics research at Birmingham has come full circle, from the fundamentals of topological phases to applications in new areas. The future looks bright for this fascinating area of research.
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Legal rights to DNA have yet to keep up with the times
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Tiffany Idle unravels the legal issues surrounding ownership of DNA samples.
sensitive information for both the is very little incentive for public or orking at an NHS person and their family members. private services to use genetic data in a genetics diagnostic lab The main benefit of this is in way that would cause a scandal or an brings with it some driving forward progress in scientific unfavourable news report, as this would inside knowledge on the law research. Large quantities of data can be result in a loss of public trust or a loss surrounding the use of DNA samples. obtained from genome sequences, of customers. Despite this, close Despite requiring consent for the use of which can be studied and utilised examination of how data will be used blood from patients, once the DNA is without the usual consent implications and familiarisation with the listed extracted, no consent is required for that can hinder research involving terms and conditions, should be anything beyond that point. There are human tissue samples. This is because encouraged when considering giving freezers full of old DNA samples, some an individual cannot block the genetic information to any DNAfrom the 90s, which can be used dissemination of important findings, or testing service. whenever needed and for whatever applications of these findings, by Legislation is yet to catch up with purpose required. Of course, they are claiming ownership of a particular gene the pace of change in this field and currently only used for the benefit of or genetic feature. This is more there are calls to put pressure on the patient, or anonymised and used as straightforward in genetic research governments to ensure that such positive controls for other patients, but than it is in the commercial sector. companies are properly regulated. This the same cannot necessarily be assumed Companies such as AncestryDNA™ would help protect consumers by of a private company. and 23andMe™ provide personal preventing companies from The Human Tissue Act of introducing unsavoury practices, The future ofmedicine could be “all for 2004 only protects any material for example selling data to health one”, rather than “one for all” that contains, or is likely to insurance companies to allow the contain, complete cells, which is not genetic analysis services that are justification of price hikes or reduced applicable to extracted pure DNA. The increasing in popularity, with the coverage depending on personal risks. ability to test DNA, and ownership of global market estimated to increase to Better regulation would also allow each genome sequences, does not involve approximately £7.7 billion by 2020. individual to make a fully informed the person from whom the DNA They claim to provide information decision. was obtained. Furthermore, the about a customer’s heritage, what In the future, similar services could person does not have legal fitness plans would work best for them become more integrated within ownership of the and predisposition or presence of genes healthcare systems, with possible knowledge acquired related to certain health conditions, outsourcing of data collection and from sequencing, such as Parkinson’s disease. The analysis to private companies. The fast which, when reliability and interpretation of the pace of improvements to sequencing tied to findings can be somewhat dubious at technologies means that this could personal present, with the companies stressing accelerate the development of genetic details could that customers should not use these kits health services. If all goes well, it could be quite for diagnostic purposes; however, this play a part in the advancement of may improve as time goes on. personalised medicine: the likelihood These companies do have a policy of developing a disease, it’s progression, restricting use of the genetic data particular treatment effectiveness, and that they acquire; they can only prognosis would all be specific to the use it for their own services, for patient. The future of medicine could the improvement of these be “all for one”, rather than “one for services and to aid all”. in research. There
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Causal wizards and D Callum Gill discusses the link between causality and time travel in popular fiction
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ime travel is featured quite heavily in popular fiction. Many different mechanisms of time travel have been devised which have caused much analysis and debate between the consumers of these stories. However, what’s also interesting is how these various stories handle the concept of causality and the very outlook of the timeline is underpinned by causality, whether it be explicit or not. But first, what is causality? Causality simply means 1955 that every effect has a cause, without which it cannot occur. However, certain events cannot influence others if the information that these events have taken place does not move fast enough to produce the effect in question. This is because the fastest possible speed information can
"Each event is caused by a hundred ofdifferent events, making causality extremely complex...influencing a past event can create cascades ofbranches" travel at is the speed of light. If you shoot a laser beam at the moon, the event in which the light has reached the surface of the moon depends on how long it takes for the laser light to reach it. You cannot immediately cause that event. Realistically, each event is caused by a hundred of different
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events, making causality extremely complex. This is one of the reasons why it is an avenue so many science fiction writers love to explore. In considering time travelling to the past, there are two distinct types of
Marty travels back
New Timeline
situations that could arise due to causality. There’s the inconsistent case in which the act of travelling back in time causes a new branch in the timeline, as the act of time travel had not occurred in the original timeline. This results in a butterfly effect:
Original timeline
Marty does exist Marty doesn't exist influencing a past event can create cascades of branches. You will often find that most stories depicting time travel will use this as a key plot point. Alternatively, there’s the selfconsistent case, in which the act of time-traveling simply causes us to travel back in time and live out history as it originally played out. Therefore, it causes no deviation from the original timeline. In the film Back to the Future, teenager Marty McFly accidentally travels back in time in a modified DeLorean to the year 1955 and meets his parents. Whilst in the past, he prevents his parents from becoming a couple, thus inadvertently creating a
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DeLoreans new timeline where he slowly becomes the past doesn’t erased from history. Since this alter the timeline in any timeline is inconsistent with the way. It had all already original, Marty’s existence happened, both for the past Harry begins to be erased and time travelling one. Despite since no event carrying out the act of saving him and has occurred to his friends, Harry doesn’t have any free allow him to be will whilst travelling Harry is in the past. He had to born. However, by getting his saved carry it out, otherwise parents together, he would create a cascade of cause and effect that Past eventually results in his birth.
"Despite carrying out the act ofsaving him and his friends, Harry doesn’t have any free will whilst travelling in the past."
Harry travels back Future
the timeline wouldn’t be selfconsistent. It’s clear that traveling to the past depends heavily on causality, potentially limiting our experiences Harry Potter and the Prisoner of there. These stories highlight that either we can influence history to play Azkaban, by J. K. Rowling, features a self-consistent timeline. Here, Harry out differently or we are merely a part and Hermione decide to travel back in of the history that is already set in stone, and no amount of time travel time to find out the identity of an unknown figure who saved them from would change it. What if we are, in fact, experiencing a set of events caused by a dementors. Once they arrive at this past event, they discover that no-one is time traveller? What if time travellers there to save them. Harry then realises live among us and this is how history is meant to be? What if our past, present that he’s the one who in fact saved them. This makes logical sense from a and future are constantly changing, we are completely "What ifour past, present and future and oblivious, much like Marty’s are constantly changing, and we are parents? Are these all completely oblivious?" wonders of the human mind causality point of view, since the event that will only ever be discussed within of being saved had already happened popular fiction? for the time-travelling Harry, so simply performing the act of saving himself in
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Rhythm, interrupted: How modern society Farhana Alam discusses the effects of a modern lifestyle on circadian rhythms and on human health.
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n 1729, French astronomer, Jean-Jacques d’Ortous de Mairan, placed a mimosa plant into a dark cupboard and observed that the raising of its leaves at dawn, and their drooping at dusk, continued despite the lack of a light stimulus. The plant appeared to have its own, internal 24-hour cycle. It was another 230 years before the word, “circadian” (meaning ‘around a day’), was coined. We now know that circadian rhythms are present across the domains of life: in bacteria, fungi, algae, plants and animals. In mammals, the main circadian pacemaker is in the suprachiasmatic nucleus (SCN); a tiny brain region located above the junction of the two optic nerves. The SCN is driven by changes in light intensity, detected by nerve cells in the retina, and it regulates subsidiary clocks, present in almost all cells of the body. The 2017 Nobel Prize in Physiology or Medicine was awarded to Jeffrey Hall, Michael Rosbash and Michael Young, for their identification of ‘clock’ genes that drive the cellular process in these subsidiary clocks. The period gene encodes the PER protein, which is produced at night but degrades during the day. The timeless gene encodes the TIM protein, which is required for entry of both proteins into cell nuclei, where they inhibit the period gene in a classic negative feedback loop. Circadian rhythms influence a plethora of physiological reactions. The inflammatory response is greater during the night, as a body at rest is better able to fight off infection; however, this means that the time of day that a person has surgery or takes a drug/medication will affect its outcome. Car accidents occur at a disproportionately higher rate at around 3am, due to low alertness, and workplace accidents are also more likely to occur at night. In 2011, the World Health Organisation produced a list of health risks associated with shift work. These include gastrointestinal
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disrupts our body clock disorders, cardiovascular conditions, breast and colorectal cancer, preterm delivery and psychological health problems. Sleep and circadian rhythm disruption (SCRD) has been reported in over 80% of depression or schizophrenia patients, and is also linked to neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. However, the direction of causation in these cases is unclear. The most well-known disruption to circadian rhythms is jet lag, caused by mismatching of internal and external clocks. In fact, patients with cardiac disorders are at greater risk of heart attack not just after long flights, but also in the week following clocks going forward or backward. Teenagers are a special case; between ages 12–20, humans have a delayed body clock, resulting in later sleeping/waking times. Adults tend to be fully alert by 10am, but most teenagers are not fully alert until 12 noon, with 10–20% not fully alert until 2pm. Unfortunately, this means that changing the timings of the school day to benefit students may result in poorer quality teaching from tired teachers; a quandary! Our 24/7 society is making SCRD more prevalent. The vast majority of the population awakes well before their circadian clock would naturally wake them, whilst radiant screens and bright LED streetlights prevent early nights. These disruptions have coalesced into what is termed ‘social jet lag’ (SJL), which is defined as the difference in sleeping hours between work days and free days and is exacerbated by the pandemic use of alarm clocks. SJL is now widespread and is linked to increased risks of developing obesity (33% increased risk for every hour of SJL), Alzheimer’s and cancers. The best way of combatting SJL is to stick to a routine of waking, eating and sleeping like clockwork, i.e. tune in to your own rhythm and try not to step out of time!
PICTURE: PAMANDEEP SANGHA
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Oblivion: The death of the Universe Patrick Regan examines the theories behind the inevitable end of the universe
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here will come a time when nothing will remain of what we call our universe. Every star will fade and all matter will decay into radiation. The cosmos will be stagnant and dark. Chaos will rule. In general, the universe tends towards chaos (or disorder), but what does this mean? We know from our own experiences that the longer we leave something, the more likely it is to fall apart. Take a student’s bedroom for example. It may be tidy at the start of
less ordered. Now, think of the universe as a cosmic bedroom. Currently, we can consider it to be ordered because it has billions of galaxies with stars and planets inside them. But as time goes on, everything becomes less ordered. Eventually the stars will explode and die and after many generations, the gas clouds in deep space used to form suns will have run out of fuel "...time as we know it will cease because and no new stars will be the universe will have reached its final formed. Galaxies will state and remain this way: cold and collide, merge into one unchanging for eternity." and eventually be sucked into the supermassive black holes at term, but as the year progresses: plates will pile up on the desk, sheets won’t their centres. Even these black holes have been washed and the piles of will lose energy and evaporate over clothes on the floor will make the trillions of years. Once this has colour of the carpet a distant memory. happened there will be no matter left This is because it takes energy to in the universe, it will have all decayed maintain order - energy which a into energy. student may not have. At this point, the universe will Note that in physics when we say continue to become more disordered as order, we are simply referring to how each particle of energy moves as far tightly particles are arranged. away from its neighbour as possible. In Intuitively, we know that a brick is an ever-expanding universe, these more ordered than a pile of dust. Ice is particles will eventually become more ordered than steam because its infinitely far apart. When this atoms are closer together. A universe happens, time as we know it will cease that is filled with complex structures because the universe will have reached such as galaxies and stars is more its final state and remain this way: cold ordered than one that only contains and unchanging for eternity. distributed particles of energy. When However, the end of the universe particles are more spread out, they are need not necessarily be so bleak. There
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is another theory known as ‘the big crunch’. This theory takes a more symmetric view of the life cycle of the cosmos. It proposes that the expansion of the universe will one day slow down and change direction, contracting inwards. All matter would get closer and closer together, eventually reaching a single, infinitely dense point. This would lead to another big bang and the creation of a new universe. It’s theorised that this has already happened and that we are merely one iteration of a never-ending cycle. No one knows for sure what the fate of the universe is. However, if the inevitable end of everything is still troubling you, take solace in the fact that the cosmos might not die but be born anew and even that won’t be happening for a very long time.
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Why must we follow time’s arrow? Luke Kurowski-Ford analyses the significance of entropy as an obstacle to time travel in a macroscopic world
he concept of an ‘arrow of disordered as the pack is shuffled and time’ is very instinctive. It all the cards randomly intermingle. matches what we have However, all the possible experienced since our first moments arrangements of the cards are just as in this world; the past is always behind us, immutable, and unique as one another – there’s nothing special about the the future always ahead, a constant mystery. But why is it initial arrangement we described. The only reason why the that the arrow is so uncompromisingly fixed forwards? Why shuffled arrangements appear so ‘disordered’ is because they are we unable to change the direction of the arrow and travel are harder to distinguish than the ‘ordered’ ones, such as backwards in time? alternating black and red cards or all the cards in numerical A world moving backwards in time would behave how a order. These so called “ordered systems” have a large-scale video plays when it is rewound. It would be a very strange pattern or structure that allows us to identify them, without place to live; there would be numerous events that would having to worry about the much more complicated smallseemingly defy the laws of physics, such as a pile of bricks scale arrangement. spontaneously rising to form a block of flats or an apple And this is the problem with entropy – it arises from an suddenly leaping up and attaching itself to tree branch. approximate, low-resolution view of the universe. We live in While these events may seem unlikely, they are not a macroscopic world and so are unable to see all its details. impossible. For an apple to jump back, heat energy around For example, if you zoom in on glass, you will find that its the apple would converge molecules are in constant turmoil, randomly moving and "Entropy...is the only into it and be converted colliding with each other. Regardless of whether the glass thing prventing us from into kinetic energy. may seem to be ordered, such as in the shape of a stein, or freely moving through Under Newton’s laws of more disordered, such as in pieces on the floor, the molecules time in any direction mechanics, it would be behave the same. As you go to smaller and smaller scales, feasible for a world to exist where time was reversed. entropy becomes increasingly difficult to define, as does In our world, however, heat – being the random motion time. This is why in quantum mechanics, on the smallest of particles – always disperses, and so we never see it scale of the universe, time behaves in a very strange way. In converge on objects to cause them to move spontaneously. some equations in quantum mechanics, such as the WheelerThis is because everything in the universe is far more likely Dewitt equation for quantum gravity, time does not even to become disordered over time; it is more probable that a seem to exist. structure of objects will collapse into a disorderly heap Time, despite its seemingly vital importance in the "Life than it is that the heap will gather itself back into functioning of our world, might not actually be a can only the original structure. In physics, the amount of fundamental property of the universe. It seems to be disorder is called entropy, and one of the only emerge on large scales, where the understood fundamental laws of thermodynamics intricacies of the small-scale composition of backwards; but it states that entropy always increases over must be lived forwards.” the universe are inconsequential, and the time. This is the only law of physics world is governed by macroscopic that is directional in time, with all structures. Unfortunately, we - Søren Kierkegaard, 1844. other laws of physics operating inhabit the large-scale domain, in the same way when time and so are led along a narrow runs backwards. And so, entropy is the only law in path through time. To escape the path, and travel physics requiring the arrow of time to only point freely through time, would require us to experience forwards. It is the only thing preventing us from the universe on the quantum scale – an experience freely moving through time in any direction. very different to what we are used to. We would A good example of entropy is shuffling a have to see our world not as a collection of wellpack of cards. It makes intuitive sense that a defined objects, but a chaotic sea of an uncountable pack arranged with alternating black and red number of particles. The world without the arrow cards is ordered, and then becomes more of time would be a world unrecognisable as our own.
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PHOTOS COURTESY OF LUCY COOKE FOUNDER OF SLOTH APPRECIATION SOCIETY WWW. SLOTHVILLE. COM PICTURE: KANENORI AUTHOR OF LIFE IN THE SLOTH LANE
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Hanging around: why do sloths move so slowly?
Adam Dorey delves into the strange, sloweddown world of sloths.
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ome of us would enjoy the lifestyle of a sloth; no which in turn slows down their behaviour. pesky commitments other than hanging from a As sloths have evolved over time, one unique anatomic branch all day – and imagine getting ten hours of adaptation explains why 90% of their time is spent hanging sleep a night! It is common knowledge that sloths move upside-down. Scientists had wondered how sloths could slowly; the Spanish word for sloth, ‘perezoso’ literally spend so long upside-down – surely the weight of their translates as ‘lazy one’. But what is it about their biology that abdominal organs would put too much pressure on their enables such sluggishness? lungs for them to breathe easily. To mitigate this ‘squash Sloths are not just slow in their behaviour, but their low effect’, researchers found that sloths have adhesions metabolism means that their lethargy extends to a cellular composed of fibrin (a fibrous protein involved in scab level. All organisms have a basal metabolic rate (BMR), formation in humans), which attach a sloth’s abdominal which is the rate at which a resting organism uses energy to organs to its lower ribs. When a sloth is upside-down, these keep their vital bodily processes organs are held in place above its functioning. What is unique about lungs, letting sloths breathe a little sloths is that their BMR is half the more easily as they hang around. rate that would be expected of an average One slightly gross consequence of mammal of the same size. This explains slowness in sloths is that it allows a diverse why sloths are slower than the average variety of other organisms to live on their mammal; it takes a long time for them fur, including algae, moths and to ‘turn over’ energy at the cellular detritivorous fungi. One species of pyralid level. moth exclusively lives in sloth fur, even Interestingly, an organism’s using it as their mating ground! (Imagine having metabolism is linked with how it perceives insects getting freaky in your hair. Nasty.) Continuing with time: the smaller and faster an organism, the shorter the the grossness, as sloths descend from their tree to defecate, intervals it can comprehend.While this may explain why female moths lay their eggs in the sloth’s faeces, where their flies seem to be one step ahead of every rolled-up newspaper, larvae can live a happy, if smelly, childhood. As these moths it could also imply that sloths actually do not notice how fast shuttle from the loo to their furry home, they act as nutrient time slips by. It is possible they just think the rest of us are portals, providing nutrients for commensal algae, which buzzing around too fast. sloths use as a lipid-rich food source. An entire ecosystem Another factor is how sloths respond to temperature functions in a sloth’s very own fur, resulting in a three-way "An organism’s metabolism is linked mutualism changes in their environment. Sloths are heterothermic, meaning their core body temperature with how it perceives time: the smaller where sloths can fluctuate to about 5 degrees Celsius either side of and faster an organism, the shorter the can receive their average. Initially, their temperature increases tasty intervals it can comprehend." with the environment, but after reaching an optimum, nutrients the correlation stops and contrary to the rising from algae whilst little moth babies are being made – all environmental temperature, theirs decreases. No other enabled by physiological and anatomical features that slow mammal can actively decrease their core temperature in this these leisurely mammals right down. way. Again, this enables the lowest possible energy expenditure, slowing down their cellular chemical reactions,
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Saving our future: Learning from the dinosaurs
Mia Wroe urges the public to learn from the past to save the future in the face of impending global catastrophe.
extinction event, the Anthropocene extinction (named so for the role we ir Charles Lyell, pioneering way that modern fauna do. When their have played in it), is one, not caused by geologist and close friend of extinction did come, it was met not by a a sudden and uncontrolled asteroid Charles Darwin, famously said group of grossly colossal animals too impact, but by a more gradual that “the present is the key to the past.” stupid to adapt or even react, but by a greenhouse effect. We still have the While this is very much a group of animals whose reign over our chance to change our future by taking commandment in the field of geology, planet had been more successful than active measures in a way than no other it can be reversed to produce another any before it and any that have species has had the opportunity to do. important credo: the past is the key to followed. Implementing sustainable development the present and the future. We currently stand on the precipice programmes and renewable energy We all know the story of the of another mass extinction, caused by sources capable of replacing our fossil dinosaurs; as children we’re told of the climate change greatly aided by our fuel dependency are essential steps in monstrous beasts that dominated our own destructive actions. If anything, avoiding the impending global planet 66 million years ago, of the the fall of the dinosaurs should be catastrophe that sits just around the formidable Tyrannosaurus rex "When their extinction did come, it was met corner. and the iconic Diplodocus. We There is a further message of not by a group ofgrossly colossal animals are also told that this is a story hope in this story, though we too stupid to adapt or even react, but by a must turn to the skies to see it. ending, ultimately, in failure. A group ofanimals whose reign over our From the Cretaceous-Paleogene failure to adapt, to evolve, to planet had been more successful than any extinction arose all ten survive. We are left with a before it and any that have followed." thousand species of bird we see lingering image of these great lumbering brutes, too large and taken as a warning. The past is the key today. Avian dinosaurs outnumber unintelligent to be successful, making to the present - it is something that is mammalian species three to one. As their own extinction inevitable. The accessible to us, that we can observe, rather appropriately noted in Jurassic manner of their extinction is almost analyse and learn from, and we have Park, “life, uh, finds a way.” inconsequential for a group of animals access to it in a way that we do not to so obviously destined for doom. the future. Before us lies a history of the However, often forgotten is the fact past 4.5 billion years; countless that dinosaurs did not just subsist here, examples of species who could not but they dominated the planet for more adapt to extremes in global conditions. than 150 million years, making our We would be foolish to ignore it. Our current meagre 200,000 thousand years look like the blink of an eye. Dinosaurs were an incredibly diverse and well adapted group of animals, filling specialised niches in the same
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ARTWORK: JACK WOOD
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ARTWORK: JACK WOOD
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