On 1st July 1838 British scientist Charles Darwin, biologist and explorer, presented a paper to the esteemed Linnean Society in London, on his theory of the evolution of both mankind and animal life. He followed this in 1859, after years of controversy from fellow scientists and the Church, with his book, On the Origin of Species. The fact that Darwin was claiming, with fossil and bone evidence to back him up, that life had evolved rather than been created by God, was highly controversial in the nineteenth century. Even with the catalogue of physical material supporting his theory of evolution and natural selection (often known as the survival of the fittest), it was still refuted by many. Today it is accepted as fact by most of us, but there do still remain those who will debate the truth of evolution and the way it challenges the story of creation found in the Bible.
For such religious reasons, despite the majority of the population believing that Darwin’s theory is fact, the subject of whether or not evolution should be taught in schools remains an emotive one for some. The struggle to teach evolution is at its most desperate in the USA, where in places even Biology teachers can be afraid to teach it. Indeed, A Penn State news report from 2014 even stated that, “despite 40 years of court cases ruling against teaching creationism in American public schools, the majority of high school Biology teachers are not strong classroom advocates of evolutionary Biology.”
In Science (2011), political scientist M. Berkman said, “Considerable research suggests that supporters of evolution, scientific methods, and reason itself are losing battles in America’s classrooms… Only 28 percent of those teachers consistently introduce evidence that evolution occurred, and 13 percent explicitly advocate creationism.”
The situation in America in 2018 is no more enlightened. Some states of America, such as Texas, Louisiana, and Tennessee, have passed laws that permit public school teachers to teach alternatives to evolution. Yet this desire to teach Creationism rather than Evolution comes just as scientists are concreting Darwin’s theory more solidly year after year. An article in Live Science for example, says that, “Evolution by natural selection is one of the best substantiated theories in the history of science, supported by evidence from a wide variety of scientific disciplines, including palaeontology, geology, genetics and developmental biology.” Preeminent scientist Theodosius Dobzhansky goes further: “Nothing in biology makes sense except in the light of evolution.”
While evolution is facing a lack of teaching in parts of the USA, it is taught in the vast majority of schools across the UK. In fact, in 2008, the Church of England issued an unexpected apology to Darwin himself. Reverend Dr. Malcolm Brown wrote, “Charles Darwin: 200 years from your birth, the Church of England owes you an apology for misunderstanding you and, by getting our first reaction wrong, encouraging others to misunderstand you still… But the struggle for your reputation is not over yet…”
The answer to this debate, which is clearly unlikely to be one hundred per cent agreed on in the near future, would surely be to teach both the theory of evolution and the story of creation to all school children across the world, no matter their religion or background. Only by laying out the evidence can people make up their own minds, rather than have their minds made up for them by the educational, religious or political situation in which they live.
Many of you who are doing exams this year will be revising or starting to think about revising. As a tutor, I am often asked, “What should I revise?” The answer is, unfortunately, everything that you have covered in the course. No one except the exam writers know what is going to be in the exams in any single year, so always make sure that you cover everything.
Barnaby Lenon, an ex-headmaster at Harrow, has recently written in a blog that GCSE students should revise their course at least three times. The same applies for A level students, but officially there is no magic number given as to how many times you should do so. Usually, however, it will be more than once. Some lucky people, the exceptions, can read something once and it will “go in”, but more will have to go through the course over and over again for it to sink it. We are all different, and this is the main point with revising – what works for one person will not work for another.
With all this in mind, there are some tips below. Remember, some will work for you, some won’t.
• Find a good place to work. Some of you will like quiet, others will like some noise. We all work best in certain places. Some students may like to work in a library, others in their room, others in a coffee shop. Find a place that works well for you and stick to it.
• What time works best for you? Some people work better early in the morning, others in the afternoon, others late at night. Again, stick to what works for you. If you are a night owl, it’s pointless to try and force yourself to get up early and study – it just won’t work as well. Use your strengths and find the best time to suit you.
• Avoid distractions. There are so many distractions today: mobile phones, television, emails and so on. It can make it hard to study. If you are reading this now but also looking at your social media feed on your phone, for example, it’s doubtful all you are reading will go in. So avoid such distractions if you can. Turn off your phone. Turn off your emails. If you find it hard to do this, give yourself a time limit, “I will revise for one hour, then spend five minutes looking at my phone.”
• With the above point also in mind, some students find it hard to sit down and study for long periods. Others prefer it. Again, you should do what suits you best. If you do find it hard to sit for long periods, give yourself a reward. One student I worked with played volleyball at national level. He found it very hard to sit down for long periods and study. Consequently he was doing hardly any revision. We came up with a plan. He would revise for 50 minutes, then go outside and play with a ball or go for a jog for ten minutes. Then he would revise for 50 minutes again and so on. This worked well for him. You may find a similar reward works for you, looking at your phone, going for a walk, making a cup of tea, watching TV, phoning a friend and so on. Decide on your time limit and give yourself a reward.
• Aim to study for no more than two and a half hours without taking a break. You are probably not revising as well as you would if you carry on revising after that time.
• Making and reading notes and using flashcards can all work well for some students. Others can make recordings of their notes and listen back to them when they are going for a walk or even when they are sleeping at night – Mind maps and memory palaces can also be useful when revising. Again, find a method that works well for you and stick to it.
• If you are reading something and it isn’t sinking in or you don’t understand it. Try a few of the following techniques…
o Read it out loud. When you do this, sometimes it seems to make more sense.
o Try and explain it to someone else – You may find that you know far more than you think you do when you explain it to another person.
o Read it in another way. There are a lot of resources online today, so if you don’t understand your notes or textbook, look online and find another explanation.
• Making a revision timetable for when you intend to revise your subject is also useful. You may be revising for more than one subject, so work out when you are going to study and make a plan for each subject.
• Practice exam papers and old TMAs under “exam conditions.”
• Try to take off a day a week. You decide which day. Take some time off from all that studying.
• Try to start revising as soon as you can. The earlier you start to revise, the more revision you will do.
Remember, you have revised before. You know what has worked well for you and what didn’t. So if you have a good way of revising, stick to it. But if your way hasn’t worked so well, why not try another option from those listed above? There is also of course a lot of advice out there online and in books. The best way to revise is the way that works for YOU! So find your best method and stick to it.
Finally, though success in them is all about your hard work and revision, I am still going to wish you this – Good luck with your exams!
The word “hibernation” comes from the Latin word hibernare, which means, “to pass the winter.” Linked to the changing of the seasons, from the warmth of summer and early autumn to the onset of the chill of winter, hibernation is a physical state that many animals adopt to converse energy. By remaining inactive in burrows, buried nests, and hollows, hibernators’ inactivity slows their metabolism and reduces their body temperature for days, weeks or even months at a time, helping them to survive when food supplies are low. Hibernation is therefore an almost sleep-state that many animal species have evolved to help them to weather long stretches of time without needing to drink, eat or urinate.
Although some fish, amphibians, birds and reptiles are known to lie dormant during cold winter months, according to Don Wilson, a curator emeritus of vertebrate zoology at the Smithsonian National Museum of Natural History in America, “hibernation is generally associated with (warm blooded) mammals… During times of the year when that energy source is missing — especially in northern climates — one coping mechanism is to just shut down. They’ll feed heavily during the few months when food is plentiful and build up fat, then go to sleep and live off their fat reserves.”
The fat which hibernating mammals accumulate is known as “brown fat.” Mammals store this fat on their backs and around their shoulder blades as well as in their stomachs over the summer. As the animals hibernate, the dormant body can live off this brown fat, therefore ensuring that they stay alive during the harshest conditions. Female polar bears not only survive off this brown fat themselves, but often go into hibernation while pregnant, and use their reserves to feed not just themselves, but any cubs that may be born whilst they are in their annual sleep-state.
While many creatures hibernate, many others migrate. Whereas hibernation prevents animals from having to forage for food and be able to have more comfortable living conditions in winter, migration sends others on a long journey to find food, often in a much warmer climate. Migration can also be triggered by an animal’s need to breed. Humpback whales for example, travel as much as 5,000 miles to breed, while a shorebird called the bar-tailed godwit holds the record for the longest nonstop flight. It will fly an incredible 6,835 miles in eight days to find both food and a mate ( the route is shown above ). In Africa, zebras and wildebeest travel on a 300 mile round-trip to stay ahead of the rain and keep dry and have plenty of food.
Although migration and hibernation are both very different animal lifestyles and lifecycles, they are driven by the same force; the instinct to survive. The need for food, for safe warm, dry places to live, and the need to ensure the continuation of their species.
Although many nurses would rightly argue that there is no such thing as a typical day when you work as a nurse, the basic structure within a hospital setting is similar day by day.
1) The beginning of the day
When a nurse first arrives at work on their ward or in their department, they will review outpatient records to get an idea of how many patients they’ll be dealing with that day. On a ward they will also talk to the night nursing staff so they are aware of any overnight problems. After that the preparation for the day can begin, including checking which patient tests will be administered, and coordinating schedules with doctors and the operating theatre.
2) Maintenance and administration
The testing of any equipment required during the day has to take place before it is used. Nurses then have to make sure all the paperwork and spreadsheets for the day are up to date and assessed.
3) Emergencies, care and Communication
As well as their daily patient care and administration routine, nurses are constantly on hand to deal with emergencies as they occur throughout the day. The nurse is also often the point of contact between visiting relatives and friends of patients, whether in person or by phone. They will need to comfort, reassure and explain to the visitors many of the medical procedures taking place.
4) Data collection and checking
As the nurses see patients and check on all medical procedures and drug intakes, they have to review each relevant chart and record all the collected data onto computer.
Although nurses work long tiring hours, their days are rewarding, ever changing, and make a huge difference to the well-being of the world at large.
And that of a GP (General Practitioner)
A GP or doctor will face a different set of challenges every day, although the structure of a day working in a surgery always remains the same.
A doctor’s day in a standard surgery begins with paperwork. They respond to any letters from other medical practitioners, hospital discharge summaries, out-of-hours reports and patients test results. They also need to check and write out repeat prescriptions.
On average a GP will spend 45 minutes of his or her day taking telephone triage calls for people requesting appointments. This means that they listen to a patients symptoms over the phone and decide whether they need urgent, same day, treatment, or if they can wait for a later consultation.
Surgery usually begins at about nine in the morning and will last until lunchtime. There will be a second surgery in the afternoon, or late afternoon into the evening depending on the day. A doctor must see, examine, access, and treat or advise each patient within a ten minute period. They also have to make sure they are aware of each patient’s personal medical history so that a full understanding of each problem can be made.
Several times a week a patient may be considered too ill to be sent away, and an ambulance will be called to take them directly to hospital. This can make the responsible doctor’s surgery run late for the rest of the day. Even though the doctor has to care for the patient being given emergency treatment, they must also get back to his/her rooms to treat those waiting for his or her care.
Doctors also have to make a certain number of home visits to their patients each day.
As well as patient care, doctors have to attend staff meetings to ensure the smooth running of the practice as a whole. Senior doctors also often have to supervise new and junior doctors as they get to grips with the world of general practice.
As with nurses, Doctors in general practice work long hard hours. Every day is different, and every challenge has to be addressed. However, the work is rewarding, and can make a positive difference to the population as a whole.
A biologist is a scientist who studies life; specifically human, animal and bacterial, and their relationships to their environment. They do this to gain a better understanding of how our bodies work and how external factors influence each organism.
Much of a biologist’s day is spent in a laboratory using basic methods of research to analyse data and test theories. They do this by running a variety of experiments to discover as much information about their chosen subject as they can. The experiments themselves vary depending on the type of biologist, but often involve growing cultures, and watching how they grow – or not- under a variety of different conditions. They then work out how to use that data to improve healthcare, the environment or other major issues.
After deciding on a subject matter worthy of research, a scientist needs to spend time securing funding for his or her project. Therefore, biologists spend a lot of time looking for sponsorship and funding. They do this by applying for grants, writing papers, and building up a strong academic and research reputation. For every experiment conducted there is a great deal of written work that runs alongside it, so the development of a new drug, for example, is recorded at every step of the research process.
Over half of the biologists in the UK are employed in universities as lecturers and researchers. This means that at least fifty per cent of the working day is spent presenting tutorials, delivering lectures, and marking the written work of students destined to follow in their lecturer’s footsteps.
Only a small percentage of biologists are employed by the UK government these days. A large number, however, are employed in private industry; specifically in the area of drug discovery. Biological scientists employed in private industry and by the government are able to focus more on their own projects and those assigned by their superiors than by those working in a university environment, as funding is on-site, and their aim- the development of a specific ‘something’ – is predefined.
Whether they are finding ways to prevent contamination and the spreading of a virus, a cure for cancer, or working out how to keep GM crops safe, biologists have a constantly varied working day, which mixes report writing, experiments and presentations, in equal measure.
Why do leaves change colour in the autumn? It’s a simple question with a simple answer, you might say – they start to die. But there is a bit more to it than that, if you’re interested in the science, and how it can produce some of nature’s most picturesque scenery.
Every autumn the leaves from deciduous trees change colour before falling to the ground. This is due to the fact the leaves contain many chemical pigments, the most important being chlorophyll. Chlorophyll makes leaves green and helps in the process of photosynthesis, which attracts sunlight to the tree, helping them grow. Leaves also contain the chemical carotene, which has a yellow colouring. Carotene lives in the leaves all year, but is masked by the green of the chlorophyll.
The process of leaves turning from green to yellow, red or brown, is dependent on the climate. When autumn approaches and the warmer temperatures of summer begin to dip, the chlorophyll within the leaves begins to break down. Other pigments that live beneath the chlorophyll, such as the carotene, come forward.
Chlorophyll is dependent on water as well as sunshine. As the climate cools and the tree draws colder water up through its roots, the tree prepares for winter. It does this by growing a thin layer of cells over the water tubes in its leaves, closing them up in preparation. Without a regular supply of water, the green chlorophyll starts to disappear and the other colours in the leaf, such as the yellow carotene, can be seen. In some trees, when the leaf cells build, the water blocking wall which seals the tubes in the leaf’s stem traps sugar inside the leaf. This turns the sap and therefore the leaf red, or even purple.
The final part of the process before a leaf falls is when the water within the tree dries up completely. This dehydration kills any remaining green chlorophyll, as well as the yellow and red pigments. Consequently, the leaves turn brown and start to die, becoming dry and crunchy before they fall from the tree.
All in all, it’s quite a complicated and intricate process that provides us with this often beautiful time of year. When it isn’t raining at least!
Today marks the birthday of a man who History has shown to be one of the great pioneers of modern medicine, whose work led to the advent of vaccination. Bearing in mind how much we rely on these to protect us against numerous conditions and diseases now, it is one worth remembering.
Born in Berkeley, Gloucestershire on 17 May 1749, Edward Jenner was the son of the local vicar. He was only 14 years old when he became an apprentice to a surgeon, and began training to be a doctor. Working in the countryside, Jenner noticed that, despite the rife nature of the smallpox disease across England, the milkmaids never suffered from it. They didn’t even show signs of the scarring that commonly affected smallpox sufferers. He did know, however, that the milkmaids often suffered from the far less serious condition of cowpox. Jenner therefore began to work on the theory that perhaps milkmaids did catch the smallpox disease, but had somehow become immune to it.
Taking his thought processes further, Jenner speculated that if you had the relatively harmless cowpox, then perhaps you wouldn’t get the far more lethal disease of smallpox at all. Wanting to prove his theory, in 1796 Jenner carried out his now famous experiment, which involved using a needle to insert pus from Sarah Neales, a milkmaid with cowpox, into the arm of an eight-year-old, James Phipps. A few days later, Jenner then exposed James to the smallpox. The boy failed to contract the disease, and Jenner concluded he was now immune to it. Calling this new method vaccination (after the Latin word vacca, meaning cow), Jenner submitted a paper to the Royal Society the following year about his discovery. It was met with some interest, but further proof was requested. Jenner proceeded to vaccinate and monitor several more children, including his own son.
Although the results of Jenner’s study were published in 1798, his work met with opposition, and even ridicule. It wasn’t until 1853, 30 years after Edward Jenner had died, that his smallpox vaccination was to be made a compulsory injection across both England and Wales. However, Jenner’s work would ultimately lead to a wave of medical innovation, and further, to the large number of life saving vaccinations available today. For this, he is surely worthy of remembrance.
Almost every health scare these days seems to concern viruses. From bird flu and Ebola and now to Zika, these pathogens appear to have medicine on the hop. But what exactly is a virus, and why are viruses such a problem?
A typical virus is a remarkably simple machine. It is just a short stretch of nucleic acid (DNA or RNA) surrounded by a protein coat. The nucleic acid contains coded information for making new virus particles, while the protein coat may help the virus gain access to its host. And that is that. Viruses have no membranes, no complicated machinery for carrying out reactions, and no metabolism like one of your own cells. Viruses do not feed, move, or respond to their surroundings like proper organisms. And they are so small that they were not even visible until 1939, following the development of the electron microscope.
However, introduce a virus into a host cell and the results are dramatic. It hijacks the cell’s processes and redirects them exclusively to the manufacture of more of itself. New virus particles are then budded-off from the surface, each surrounded by a piece of host cell membrane. Or, the cell splits open, releasing hundreds of new particles to infect other cells. Either way, viruses damage and kill our cells, which is what makes us ill when we have a viral infection.
Another trick of viruses provides a hint as to their origins. The genes in our own cells are remarkably like virus particles, also consisting of nucleic acid (DNA in this case) surrounded by protein. Sometimes a virus splices itself into this host DNA like an extra gene. The virus then lies low, being copied with the rest of the DNA when the cell divides, and passing to each of the daughter cells produced. Later, it may emerge without warning to form more viruses in the normal way, causing illness years after it first invaded. This is what happens when the chicken pox virus causes shingles in later life, or when people recovered from Ebola relapse, as recently happened to the Scottish nurse Pauline Cafferkey.
So, if viruses are constructed and can behave just like normal genes, perhaps that’s what they really are? Perhaps they are “escapee genes” that left their cells long ago to take up an independent existence? That would explain why they find it so easy to invade and take over our cells, and why we find it so difficult to defend against them.
Whatever the truth of their ancient origin, viruses present modern medicine with a formidable challenge. Antibiotics do not work against them, and the particles mutate rapidly to keep ahead of vaccines prepared to defeat them. One thing is certain: Ebola and Zika are not the last health scares that they will bring us.
Viruses and the diseases that they cause, including ‘flu and Ebola, are covered in depth by the new A Level Biology course recently launched by Oxford Open Learning. You can find out more about the course here: http://www.ool.co.uk/subject/a-level-biology/
By far the biggest killers in today’s Britain are cancer and circulatory disease. Of the 501, 424 people who died in 2014, 29% died of cancer and 27% from heart attacks plus strokes. There is no doubt as to why charities seeking a cure for these scourges attract so much public support.
By contrast, leaving aside ‘flu and pneumonia, which mainly kill the already weakened elderly and infirm, infectious diseases account for a mere 0.6% of deaths. Your chances of being cut down by one of these in your prime of life is comparable with that of the threat from road traffic accidents or suicide. The reason we are dieing largely from heart disease and cancer is not because they are becoming more virulent, then. It is simply because we are living longer. Whereas in 1900 the average life expectancy in this country was just 48, now it is 81.
Antibiotics, the drugs used to treat bacterial infections, are a recent invention. Alexander Fleming stumbled upon them by accident in a London laboratory in 1928, though the first, penicillin, only went into mass-production in 1944. When it did so, it reduced at a stroke the number of deaths from infections, making hospital operations safe, battlefield wounds less fatal, and many serious diseases treatable.
Bacterial resistance to antibiotics emerged as a problem in the 1950s, but it has now become critical. Resistant bacteria have the ability to transfer their resistance to other species as well as passing it on to their offspring. So, once established, resistance to a particular antibiotic spreads rapidly, and bacteria with multiple resistances emerge. By 2004, bacteria resistant to almost all known antibiotics had appeared, while in 2015, bacteria resistant even to the”antibiotic of last resort” appeared in southern China. It is expected to spread to the west shortly.
In April 2014, the World Health Organization (WHO) sounded the alarm on this topic in no uncertain fashion. It spoke of a “major global threat” from such antibiotic-resistant bacteria, and an imminent return to a pre-antibiotic era, where people regularly die from the simplest of infections. If and when this happens, you would be far more likely to die from sepsis following a cut, or from airborne or waterborne bacterium, and less likely to live to an age when cancer and heart disease are a concern.
There is, though, a glimmer of light on this dark horizon. Traditional antibiotics are developed from defensive chemicals produced by fungi and bacteria. However, our own cells also produce chemicals that attack bacteria. They are short proteins (peptides) produced on our own cellular protein-assembly machines, called ribosomes. From this comes their acronym, RAMP antimicrobials (ribosomally synthesized antimicrobial peptides). These antimicrobials carry a positive electrical charge on their molecules and are attracted to the negatively charged outsides of bacterial cells. Once attached to the bacteria, they punch holes in the bacterial wall or membrane, killing the cell.
These natural defence molecules have been around for millions of years, during which time bacteria have failed to develop effective resistance to them. So, if this is the case, and if effective artificial mimics of natural RAMPs can be made, we may yet avoid a potential return to the dark ages of pre-antibiotics.
Bacteria, the discovery and action of antibiotics, and the emergence and spread of resistance, are all covered in depth in the new A level Biology course recently launched by Oxford Open Learning. You can find out more about the course here: http://www.oxfordhomeschooling.co.uk/subject/biology-a-level/
Charles Darwin was born on February 12th, 1809, in Shrewsbury, Shropshire, England. Although he had no formal education as a botanist or naturalist, Darwin was fascinated by natural history, and dedicated his life to its study.
In July 1838, Charles Darwin presented his paper on his theory of evolution to the respected Linnean Society in London for the very first time.
Having worked on his theory for over twenty years, Darwin’s thoughts on how animals and mankind evolved through a process of natural selection had a major impact on the scientific world and the church. Until Darwin began to share his ideas, ideas about natural history had been dominated by the Church of England, who saw the origins of all living things as working to God’s plan.
Darwin’s theory stated that within a species, individual animals show a wide range of variation. These individual animals with characteristics most suited to their environment are more likely to survive and produce offspring. He also said that the offspring of stronger parents would be more likely to survive than others, as would their own children. By contract, those creatures that are poorly adapted to their environment are less likely to survive, and therefore less likely to successfully reproduce.
Darwin conclude that over a long enough period of history therefore, a species would gradually adapt to best suit its environment, and would evolve into a stronger group. Those species that were weak would die out. This theory became known as ‘Natural Selection’ and coined the phrase ‘The Survival of the Fittest.’
Darwin began writing down his ideas on evolution in 1836, after the end of his five year voyage of discovery on the HMS Beagle. By December 1838 he had developed the main principles of his theory. Over the next few years he went on to refine his ideas with the help of three close supporters, geologist Charles Lyell, botanist Joseph Dalton Hooker and naturalist Thomas Huxley.
The help of Huxley, Lyell, Hooker and others was essential, as Darwin was widely criticized, especially by the church, for his ideas. Ideas, of course, which science has since proved to be correct.