What is worth conserving?

All species have to endure competition, this may be for space, changes to predation or resources, but in some cases a species may be unable to sustain the fight and suffer population decline; we often hear of organisms such as the Black Rhino which has under 5,000 individuals and despite zealous conservation measures continues to suffer losses, for example by illegal killing for the dubious merits of treatment by extracts from their horn.

Of course periodic extinction of species has happened throughout the biological lifetime of the planet, it’s nothing new and is to be expected when conditions such as the climate change, or when catastrophic events occur such as a large meteorite impact. An example of this is the “Permian-Triassic extinction” 252 million years ago when 95% of marine species and 70% of land species were wiped out. Even species that were common and had a long history of success such as the Trilobites were not insured for this event.

They had existed for about 270 million years, but whatever happened 252 million years ago was not survivable for any of the Trilobites. It makes picking a winner species in the game of life more like a lottery. Looked at in the long view these events are not without benefit since the new ecological niches available after the departure of their previous inhabitants can encourage adaptation to incomers who in turn can evolve independently and form new species. In this extreme case, the “Permian-Triassic extinction”, recovery was slow possibly because so much biodiversity was lost.

Rocks from a time when diversity was in fashion: the Pillow Lavas of Anglesey mark the end of the Pre-Cambrian and the start of the Cambrian ‘Explosion’ in Biodiversity'

It’s not so simple for us though, we are “knowing” animals and live for a brief time in relation to the lifetime of the planet. Our cultures have often developed our sense of responsibility towards other species, but it is obviously not possible for us to prevent natural events of the death and birth of species although we feel intimately bound in the process, a good example being the Passenger Pigeon. This animal was endemic to North America and existed in immense numbers, a flock seen in 1866 took 14 hours to pass overhead, being 300 miles long and 1 mile wide and this was just one flock! By 1914 the bird was extinct. The usual suspects seem to have done for the species: its habitat had changed through increased competition and predation had increased, both brought about by our own species.

It is obviously not possible is to conserve everything so decisions on what to conserve are important. Such decisions often are based on subjective criteria, Pandas come before the Poison Dart Frog and the Florida perforate reindeer lichen can happily go bust. It is therefore important to identify criteria for conservation which are as objective as possible, this in turn poses the question of how do we select the criteria themselves. One possible criterion for conservation would be the use to humans. This has historical pedigree, for instance trees for construction and wheat for food, a plant which probably would not survive without cultivation and human aided distribution because of large size of its seeds.

There are other uses of course, medicines: willow bark as a source of aspirin has been used for centuries, but new drugs are being found in extracts from plants such as the Madagascar periwinkle (Catharanthus roseus) used to treat childhood leukaemia and Hodgkin’s disease. Then there is conserving as an insurance policy, preserve species so that if conditions on earth alter we will have suitable species, or at least their DNA, to help deal with the new conditions.

We may need to decide on how unique a particular species is before attempting its conservation. Looking at the morphology does not yield the answer, Peacocks look pretty amazing, but in reality are one species of many related birds in the Galliformes order which contains the Turkey and the Chicken. There are methods available to determine how unique and therefore valuable certain species are, such methods rely on cladistic relationships between species as determined by the similarity of their DNA. What this means is drawing a special graph (called a Cladogram) to display the species, the lines between the species indicate evolutionary relationship and the length of the line indicates the amount of genetic change:

The choice of preserving D, for example is poor because it shows little genetic uniqueness from E. The more unique species is B, so given the choice of preserving B or D, B must win.

Now try these questions

1. Summarise the advantages and disadvantages of major extinction events.
2. Argue the case that we may be witnessing a major extinction event, what are the driving factors for extinctions, should we do anything about it; is it feasible to resist the changes?
3. What effect does a major extinction have at the individual, species and phylum levels?
4. What can we learn about evolution from studying very ancient ecosystems such as the Burgess Shale?
5. Summarise the use of cladistics in the study of evolution. How can this study be combined with analysis of DNA sequences to decide on the uniqueness of species?
6. Why should organisms be conserved? What additional problems are there, ecological, political and social which make the preservation of species particularly difficult?
7. Make the case for the conservation of an organism of your choice.

Reading around the subject

The “Cambrian Explosion”, that is in diversity:
http://en.wikipedia.org/wiki/Cambrian_explosion

The importance of biological data to land developers and planners http://link.springer.com/article/10.1023/A%3A1008165311026

Some examples of syllabus content for which the above exercise is relevant:

John Giles

Business News Quiz

The UK economy has avoided falling back into a recession after recording faster-than-expected growth in the first three months of the year. By what amount did the UK grow?
0.3% ( ) 1.3% ( ) 0.5% ( ) 1.5%( )

Which European countries unemployment rate soared to a new record of 27.2% of the workforce in the first quarter of 2013, according to official figures? 
Portugal ( ) France ( ) Spain ( ) Germany ( )

The eurozone's biggest bank, suffered a 25.9% fall in profits for the first three months of the year. Which bank is this?
Credit Agricole ( )   BNP Paribas ( ) HSBC ( ) Santander ( )

A broadband bill sent to a deceased man, which included a fine for late payment, has been shared more than 53,000 times by Facebook users. Which company sent this?
Virgin Media ( ) Sky ( )   Talk Talk ( ) BT Vision ( )

Who has released a mobile phone with a dedicated WhatsApp physical button. The feature triggers the cross-platform messaging app which offers a free alternative to SMS texts
Samsung ( ) HTC ( ) Apple ( )         Nokia ( )

Which technology maker has reported its first quarterly drop in profits in a decade, but said it will raise dividends for shareholders. It made a net profit of $9.5bn (£6.2bn) in the January to March quarter, down from $11.6bn last year?
Microsoft ( ) Apple ( ) Yahoo ( ) Google ( )

The planned sale of 631 UK bank branches by Lloyds Banking Group to which bank has fallen through. They have blamed the continued economic downturn and tougher regulatory environment imposed on bank?
Virgin Money ( ) Co-op ( ) Natwest ( ) HSBC ( )

Who has doubled its earnings forecast for the full year to March 2013, helped by the weaker yen and money raised from asset sales. The consumer electronics firm now expects to report net income of 40bn yen ($403m; £261m) compared with its previous forecast of 20bn yen?
Sony ( ) HTC ( ) Dell ( ) Samsung ( )

Which online retailer saw a fall in profits but rising sales in the first three months of the year. The company, which is the world's biggest online retailer by sales, recorded a net income of $82m (£53m) for the quarter, down 37% on last year?
LL Bean ( ) Best Buy  ( )   Netflix ( ) Amazon ( )

Which country  has agreed to buy 60 planes from European firm Airbus, in a deal worth $8bn (£5.2bn) at list prices. It is the first such deal since the European Union suspended the inclusion of foreign airlines in its controversial Emissions Trading Scheme.? 
United States  ( ) Russia ( ) India ( ) China ( )

Answers –

1 – http://www.bbc.co.uk/news/business-22290407
2-  http://www.bbc.co.uk/news/business-22290422
3 – http://www.bbc.co.uk/news/business-22290414
4 –  http://www.bbc.co.uk/news/technology-22283453
5 –  http://www.bbc.co.uk/news/technology-22278955
6 – http://www.bbc.co.uk/news/business-22274324
7 – http://www.bbc.co.uk/news/business-22276082
8 – http://www.bbc.co.uk/news/business-22292524
9 – http://www.bbc.co.uk/news/business-22304280
10 – http://www.bbc.co.uk/news/business-22305182

Donna Jestin

Trio of Success: writing, improving and commenting

This activity is designed to improve students’ extended writing, primarily at KS4/5. The key foci here are:

• The process of writing, linking and arguing
• The skill of using advice to improve the quality of work
• The application of a mark-scheme to a piece of written work to make a judgement

Though the outcome of the activity can be for students to receive a mark if you choose, they need to understand that what is more important in this case is the process through which they achieved that mark.
Ideally, the activity is hosted on a wiki – a multi-editable page – on a Virtual Learning Environment (VLE). If you don’t have access to this technology, then Google Drive (www.drive.google.com) allows students to set up a multi-editable document and email the link to everyone they wish to access it. Alternatively a Word document emailed from student to student would work, and if none of this takes your fancy then good old fashioned pen and paper would also suffice.

Preparation

1. Split the class into equally sized teams. In the event of having an odd number of students, you could always double up roles, or introduce an element of differentiation by giving more able students more than one role. In History we tend to write a six paragraph essay (introduction, four paragraphs and a conclusion) and so my class of 18 was rather neatly divided into 3 teams which is the model on which the table below is based. However it would easily work with a different number, you simply set up a cyclical pass-on system for each of the 3 stages s modelled below.
2. Assign each student a paragraph responsibility within their team, or even better, let them make the decision themselves. Ultimately each student needs to have overall responsibility for one paragraph of the final piece of work.
3. Then you can either assign each team the same essay question, or alternatively you set each team a different question.

The 3-stage model

Stage 1 – Writing

Each team researches and writes its answer. Generally speaking they will need to write it in order – introduction – paragraphs – conclusion – and so it is a useful exercise in collaborative working as well; there can be no ‘night before it’s due’ writing!

One of the best things I have found about this exercise is that students have to pay careful attention to how the paragraphs link together to further the argument; as the thoughts preceding their own are not actually their own, they have to adapt their argument and make use of language in order to create one cohesive argument.
If you are using a wiki on the VLE, then students can all access it in order to input their paragraph. If you are using Google Drive the same applies. A word document would need to be emailed around, and pens and paper would require a cutting, sticking and photocopying job.

Stage 1.5 – you mark the first attempts

It’s important that each team have a sense of the quality of their collective attempt; individual students can look at the comments on their particular paragraph, whilst also getting a sense of how successful their team effort was in creating an overall argument. Whilst some individuals may feel this mark is not representative of their particular contribution, it doesn’t really matter – this activity is about the process.

By marking the first set of essays (three, not 18!) you can also see what each individual has achieved as well as seeing how effectively they were able to work collaboratively.

I downloaded and printed each team’s attempt, marked them by hand, and then scanned in the documents and uploaded them to the wiki for students to access electronically. You could equally use a photocopier.

Stage 2 – students improve on the first round

Each team then moves on to the ‘improvement’ stage. Keeping the same paragraph responsibility (e.g. introduction writers become introduction improvers) students then access the next team’s script, marked by you, and act on the comments made and advice given. The aim is both to read another team’s argument, and to make changes that collectively improve the quality of the work. If the essay is hosted on a wiki, or Google Drive, improvements can be made directly to the document using a different coloured text.

Stage 3 – students mark the second round

The final stage is for each team to mark the improved collective work of the other two teams (refer to the model above). Depending on your students’ familiarity with the mark-scheme, you may wish to guide them through this stage. They can of course refer to the script with your original comments completed at stage 1.5, and they are looking to mark the work as it stands, having been improved by the second team.

In this final stage, students can abandon their paragraph responsibilities and instead mark the whole piece of work. The benefit here is that they can see two versions of the work, and using the mark-scheme they can see how successfully your initial comments have been improved upon.

Charlotte Grove

Business - Top 5 Business Films

I always find that a good way to get student to really understand some of the business concepts in practice is to show clips from films – these help the students to relate the theory that they have learnt to practice in the film. Also, some of the films I have identified below are related to businesses/products that they will identify with and use on a daily basis.

I have included the trailers for each below and also what the film is about and topics it can be used for.

1. The Social Network (trailer)

This is an amazing film and a great teaching aid – for both AS start up enterprise and also A2 Unit 4 growth, ethics & the student’s research of real businesses.

Lets face it, many of our students will be ‘addicted’ to facebook and will know a little about the owner- but not how it started and the ideas of how it began.

Its also excellent to demonstrate the rapid growth of the company.

2. Rogue Trader (trailer)

Again this is an excellent film to use when studying Unit 3 window dressing, income statements – or finance in general. It’s also an great example for ethics when looking at Unit 4. 

Based on a true story, Nick Leeson, is an employee of Barings Bank who after a successful spell working for the firm's office in Indonesia is sent to Singapore as General Manager of the Trading Floor on the SIMEX exchange.

The movie follows Leeson's rise as he soon becomes one of Barings' key traders. However, everything isn't as it appears —Nick is hiding huge losses as he gambles away Baring's money with little more than the bat of an eyelid from the powers-that-be back in London.

3. Wall Street (1987 original) (trailer)

This is a great one! The original is the best, and this film from the 1980’s is based on a young and impatient stockbroker who is willing to do anything to get to the top, including trading on illegal inside information taken through a ruthless and greedy corporate raider who takes the youth under his wing.

This could be used well for finance in Unit 2 & 3, as well as looking at the human resource and ethical side of how greedy he was to succeed!

4. Pirates of Silicon Valley (trailer)

Even though a new film is currently being made about Steve Jobs, this film documents the impact on the development of the personal computer of the rivalry between Apple Computer and Microsoft.

It spans the time period of the early 1970s to 1997, when Steve Jobs and Bill Gates develop a partnership after Jobs returns to Apple Computer. Fantastic for looking at technology in Units 2 & 3 and also for leadership & culture studied in unit 4.

5. Glengarry Glen Ross (trailer)

The film depicts two days in the lives of four real estate salesmen and how they become desperate when the corporate office sends a trainer to "motivate" them by announcing that, in one week, all except the top two salesmen will be fired.

Good for looking at motivation, human resources and ethics, again for units 2, 3 & 4.

Donna Jestin

Project based learning (or, How I learned to do absolutely nothing)

I have been learning a lesson from History. Not from the annals of yore but from the History department at my school. They have been trialling the use of project based learning across Key Stages 3-5 and suggested some brilliant ideas at a recent training session. Magpie-like as ever, I have swiftly been trying them out in my own classroom with some very interesting results.

The main idea that I have trialled has been the Analysis Continuum. In the original History lesson, the lesson began with an essay-style question(e.g. Was there a cultural revolution in the 1960s?), each pair of students then drew a continuum on a sheet of sugar paper from YES to NO. They were then provided with a pile of evidence (photographs, illustrations, written evidence), which they had to sort and stick onto their continuum. A points-based system was used, with 1 point being awarded for a quotation, fact or statement, 3 points for an explanation and 10 marks for a well-reasoned conclusion.

I have so far tried this with my A level Language and Literature classes. And both times it was amazing! In the Language lesson, as with the History model, it proved to be an excellent way to impart a large amount of information (in this case attitudes to language change), without me having to be at the front of the class.

It forced students to engage with the data and develop much more solid knowledge and understanding than if I had tried to 'teach' it to them. In the Literature class, I used it to do two things. Firstly to cover a significant chunk of the text and secondly to engage with a 'How far do you agree with the statement' exam question. The 'data' in this case consisted of extracts from the text and from critics and the activity really focused my students on the process of selecting evidence and weighing it up before deciding on their line of argument.

So far I have used it with KS5 but I can envisage it working really well with my GCSE students in preparation for their reading controlled assessment essays as well. The one downside of this activity is that it takes a lot of preparation, as you need to search for, select and copy a pack of evidence for each pair of students in the class. However, once the lesson has started, you will be amazed at how little you have to do.

All of my students were enthusiastically engaged and motivated, without me having to do anything at all. In fact, I felt a bit like a spare part! The points system was great because not only did it help them to focus on the features of a well-reasoned argument but it also added a competitive element to the task.

So - the result of my History lesson? I have learned to stand back and do absolutely nothing in the classroom. Finally my students are doing more than I am!

Naomi Hursthouse

Most Multilingual Student Alex Rawling's Chinese Challenge - Week 3

A close friend once said to me that when you start learning a language, it’s like staring at a painting from really close: you can’t see much of it, and you can’t make sense of the little piece that you can. However, every time that you learn more, it’s like taking a step back, and gradually you understand how the first part fits into the wider picture. As you begin to see the whole painting, you can even start to appreciate its beauty.

This analogy has really stayed with me, and each time I learn a new language I feel myself having that sensation. This week it’s just started to happen with Chinese. In the second audio CD of the Easy Learning Mandarin Chinese course, you start to really build on the basics of the first CD, breaking up the phrases that you’ve learnt to use the words more widely, constructing more complicated, more useful sentences. I think in some ways this is the most exciting part of the learning process, as you shift up a gears and start accelerating towards speaking more naturally. As I’m starting to see the wider picture of Chinese, I’m discovering that it’s a fun language. I’m really enjoying practising the tonal system and pronunciation (although getting some strange looks on public transport), and there haven’t been any nasty grammar surprises yet. Next week I hope to be finished with the second audio CD and heading towards finishing off with the audio course so I can concentrate on the much more daunting task of reading and writing.

Superstuffs: Aspirin

250 years ago, in 1763, the President of the Royal Society in London received a letter from Rev. Edward Stone, a clergyman in Oxfordshire.  The story told in Stone’s letter began in 1758 when at the age of 56 he took a walk in the country.  He reported that he had chewed some willow bark and felt that it might have reduced various aches and pains, or “agues” as he called them.  He decided to do some careful experiments.

He collected a kilogram or so of the bark, dried it and then crushed it into a powder.  Then he started to take measured quantities at intervals of four hours and noted whether there was any change to his symptoms.  Over a few days he slowly increased the dose until he found that about 2.5g was successful.  During the next five years Stone tried out his remedy on about fifty of his neighbours and found that they too felt relief of pains and fevers.  

Stone was not the first to notice the analgesic or pain-relieving effects of willow bark although he does not seem to be aware of his predecessors.  In fact the ancient Greek physician, Hippocrates had recorded its use and people around the world used the various species of willow that grew in their vicinity.   Nevetheless, the publication of Stone’s letter in the Philosophical Transactions of the Royal Society inspired new interest across Europe in the properties of willow bark.

In 1838, Joseph Buchner, a German, isolated the active material from willow bark.  He called it salicilin after the Latin name for the willow, salix.  Two years later  Johann Pagenstecher, a Swiss found the same substance in a wild flower called meadowsweet (Latin name, spiraea) which was much more common.  In 1838 Raffaele Pirea, an Italian, broke salicin down to salicylic acid or 2-hydroxybenzenecarboxylic acid to give it its modern name.

Salicylic acid was found to have all the medicinal benefits of willow bark but it irritated the stomach sometimes causing more discomfort to patients than their original symptoms. The solution to this problem was found in 1853 by Charles Gerhardt, a Frenchman.  He added an extra chemical group to the salicylic acid to make it acetylsalicylic acid.  Unfortunately Gerhardt’s preparation was not very efficient.  It was another 44 years before the story was taken further.

In 1863, 100 years after Stone’s paper, Friedrich Bayer, a German, founded a company to make dyes.  By the 1890s the Bayer company had become large and successful and was manufacturing a range of chemicals including medicines.

A team of chemists searched for new drugs that could be sold profitably. One such drug, derived from the opium poppy, they called “heroin”.  One of the team, Felix Hoffman, found a much better, cheaper, method of making acetylsalicylic acid.  At first Bayer weren’t certain that the new drug was worth manufacturing but in 1899 they decided to market it with the name “aspirin”.

Almost immediately, aspirin was a great success and particularly during the great flu epidemic of 1918, when millions died and many more fell ill, aspirin gained popularity.  During the next century nearly everyone swallowed an aspirin tablet to cure a headache or reduce the fever of colds and flu.

Although tons and tons of aspirin had been manufactured no-one really understood how it worked until 1971 when John Vine, in London, discovered its action in cells.  Vine’s research won him a Nobel prize but it also suggested some other uses for aspirin.  It was found to reduce the chance of blood clots forming in blood vessels.  Today aspirin is recommended to anyone suffering or likely to suffer from heart or circulation problems.  Further research has shown that it may also have a role in fighting cancer.

Aspirin’s various medicinal properties mean that it is still an important product for Bayer and many other pharmaceutical companies and there is probably a packet of the tablets or powders in most homes.  The title of “superstuff” is certainly justified.

Activities

1.     Discuss whether Edward Stone was a good scientist in his work on willow bark.

2. Some years after Stone, Edward Jenner tested his smallpox vaccination on one subject, and William Withering tried out the heart drug, digitalis, on dozens of his patients.
Compare Stone’s and these other eighteenth century experiments with modern clinical tests involving placebos and double blind trials.

3. Why did the Bayer company give acetylsalicylic acid the trade name “aspirin”?  There are some clues in the article.

4. Explain why Buchner and Pirea’s discoveries were an improvement on using willow bark as a remedy

5.(A level) Hoffman’s method of making aspirin involved reacting salicylic acid with acetic anhydride.  The other product is ethanoic acid. Find out the structure of acetic anhydride, salicylic acid (2 hydroxybenzenecarboxylic acid) and aspirin (acetyl salicylic acid) and write a structural formula equation for the reaction.

Peter Ellis

Peter Ellis taught science (mainly chemistry) in secondary schools to GCSE and A level for 35 years and was a head of department for twenty years.  He is now a freelance writer of educational materials in science and dabbles in writing fiction.