Diversidad, La diversité, diverseco, vielfalt, Ποικιλία, 多样性....

The country with the largest population today is China, home to around 1.4bn citizens. It probably won't come as any surprise either to find that Mandarin (the official Chinese language) is spoken by 85% of the  population: the other 15% speak a number of regional variations of Mandarin. Today, Mandarin is spoken by around 15% of the entire population of the world (see the map). A fact that may surprise you, is that the proportion of first languages spoken in the USA, puts English out in front (at 80%), but with Spanish the dominant second language, spoken by 13% of the population, which is rising, year on year. In the UK, by way of comparison, English is spoken by 98% of the population. So while languages are more diverse in the USA than the UK, there is very little language diversity in China. In China, there is more of a dialect variation rather than a language difference, which is brought on by the size and geography of the country. Again, by comparison, the official figures for another large country such as Russia (geographically large, but with only 10% of China's population: 143m) show that over 97% of the population speak Russian. Here we have two large countries that have retained the "integrity" of their native language. Why might that be?

If you look at the countries of South America, and colour the countries by language, you learn something very quickly about world history (see the map on the right). Perhaps you might want to discuss this with colleagues? For example why is Brazil, the nearest country to Europe, one colour and the West Coast of South America another? And what about Bolivia and Paraguay? You might now want to look at the time-line of language development in the USA and the UK via Google (maybe Liverpool and New York?). Can you draw any conclusions from this historical perspective, that might help us all better deal with the  challenges of mass migration facing the world today? Hopefully, you can also begin to understand why across the world, genomes are pretty diverse and also why this will continue to be so. I hope you can see that I have been drawing on Biology, Language and Linguistics, History and Geography: this represents a a multi-disciplinary perspective on a topic; and an ability to embrace multi-disciplinarity is going to be a crucial skill in the future.
             

One of the nice things about Science (in my view) is that from one idea: spring many! In research you set out to solve a problem, and along the way you meet challenges that have to be overcome. The skills you develop in solving the first problem help you with the next. And then you find out something that requires knowledge you don't have, so what do you do? You either get to grips with this new field, or you find an expert that can help. In fact you tend to do a bit of both. This is why educators stress the importance of balancing independent working, with strong communication skills. Science (like business) is an international pursuit and so language must not be a barrier. During the pioneering days of Physics and Maths, when Sir Isaac Newton developed his theories of optics and motion (much of which made possible by his use of "calculus" to measure small changes in the behaviour of forces for example), he, like all of his academic colleagues throughout Europe, published his work in Latin (see left). One of the influences of the spread of the Roman Empire, over 2000 years ago was the spread of Latin. Latin became the lingua franca of Science communication, for many years. As you know, scientists and mathematicians still make use of Latin and Greek vocabularies (spoken words: think vocal) and Greek symbols in their research, and when they teach. Some examples would be. 

The irrational number used to determine the area of a circle (and other geometry applications) π (pi)

The dominant male in a population of primates: the α-male (alpha)  

The symbol for a wave function in Physics and Chemistry is given by ψ (psi, the p is almost silent, as in psychology)

One type of particle radiation is Physics is γ-radiation (gamma) 

Bacterial viruses (bacteriophage) are often given Greek symbols: Bacteriophage λ (lambda) being the most well known

I am sure you can think of other examples. One of the most common examples of the influences of the Classics (by which I mean the languages of ancient Greece and Rome) in Biology comes in an area that is central to our understanding of cancer. This is the area of cell division, which some of you may remember as the field in which Sir Tim Hunt earned his Nobel Prize (you can read more here). The Biologists among you will know the challenging words Telophase, Anaphase, Zygotene, Meiosis, Mitosis etc. It might be interesting to make an infographic to show the images of the chromosomes (yes another classically influenced word) at the different stages of nuclear division, along with the origins of the words? Finally, in the area of Biology, you will be aware that when searching for genes from specific organisms, you will find them under the species names as Homo sapiens or Meles meles for example, instead of Human or Badger. The contemporary field of Bioinformatics (applying computational methods to interrogate and analyse Biological data) is locked into Greek and Latin for its descriptions of organisms (look at the descriptions above). 

The influence of the classics doesn't stop here. I said earlier that, in Science, investigating one problem usually throws up another. In linguistics (the scientific study of languages) some researchers are interested in how languages emerge. Modern European languages like Italian, Spanish, and French as well as English and German owe a great deal to the classics. If I copy my last two sentences and highlight in red those words (or sometimes parts of words) that owe their origin (or etymology) to the classics, you will see what I mean!

The influence of the classics doesn't stop here. I said earlier that in Science, investigating one problem usually throws up another. In lingusitics (the study of languages) some researchers are interested in how languages developed. 

Look them up!

The study of languages is for many people an enjoyable hobby that helps make their holidays more enjoyable. It can also be an academic pursuit in itself, just like any subject. However, appreciating the diversity of languages can also lead to an understanding of many behaviours and cultures and can break down barriers. We are fortunate that English is today the so called Lingua Franca, in business and research, but this hasn't always been true and it may not be true in the future. I haven't even touched on the character differences and linguistic structures in Mandarin, Arabic and Cyrillic scripts. However, I think you can see from the sign that these non-European languages have rules that make translation into English a major challenge. As a University academic, I have supervised the PhDs of students whose first language include Arabic, Thai, Mandarin, Spanish, Turkish, German, Farsi, Malaysian, Urdu, Greek, as well as English. I have always had the utmost respect for their commitment to study Science and learn English. At the end of their 3-4 years, they must defend their research, typically to two English speaking experts....for over 3 hours! I hope, like me you develop an interest in languages, and hopefully, unlike me, a facility for them!

In my next post, next week, I will look at the concept of diversity of taste. It may be your taste in music, TV, cinema, art, or literature etc. I will explore what we mean by taste, and why diversity is good!

Measuring Diversity

There can't be many of you who haven't watched a David Attenborough documentary, or even a series of documentaries, in which he waxes lyrical about the Natural World. Whether he is talking about marine life, plant life, animals or insects, a constant theme running through his narrative is diversity. In my last post I attempted to define diversity, but when I was introduced to evolution, I thought how do we measure diversity? Darwin's theory of evolution based on Natural Selection, came out of the many observations he made on the differences between the beetles he collected at home or the finches he collected in the Galapagos Islands. There seem to be 250,000 described species of plants, 12,000 species of roundworm, only 4,000 described species of mammals, but there are over 350,000 beetle species, at the last count! Why are there over 350 000 species of beetles? Why is there a gradual change in the shape of the beak of the Galapagos finches? Both observations share a common thread: diversity.

The chart on the left from the University of Berkeley's evolution resources, reveals the range of species numbers (as percentages of the total estimated number of species on the planet). Even if it isn't a perfect set of proportions, and in fact it  excludes  bacteria and their viruses, (which will be discussed separately below), it makes quite a statement! Humans (grouped under vertebrates) represent much less than 1%  of the species on the planet. However, an interesting point for group discussion might be. While humans are in the minority species on planet Earth, they seem to have the biggest influence on the future of our planet?  Is this true? What does it say about the "balance of power" in any society or ecosystem? Do all humans have the same level of power? If not why not? 

Back to measuring diversity. There are a few ways of measuring diversity of species. The concept of species richness is perhaps the simplest (but also the least reliable). Typically you might take a small section of ground (repeated several times to improve confidence in the measurements) and simply count the number of different species/organisms. Some will be easy; insects and plants, others will require more sophisticated methods; e.g. bacteria, fungi and viruses. The experiment is an easy one to conduct and popular early on in ecology classes, whilst it does have some limitations (can you think what they might be?), it does allow comparisons to be made between different ecological niches. [The word niche comes from the Latin nidus for nest, and then from the French version, niche. In Biology it is used to describe a space occupied by a group of organisms: in business it means a segment of the market. You may have heard the expression, "niche market" which means a specialist market, such as that for vinyl records in the world of digital music?] You might carry out a survey of elephants by monitoring a section of land in Africa over a few weeks, as another example. There are of course more robust methods, which I wont discuss here. But can you find the most reliable resources (and sources) for measuring the diversity of anything from baked bean manufacturers to spoken languages? How do the numbers (or metrics) vary from one source to the next? Can you use the population of the school to measure the diversity of something. Maybe three groups could measure the diversity of the same thing and then reflect on any variation in measurements? Anything will do!

In June, 2000, President Bill Clinton and Prime minister Tony Blair stood alongside scientists from around the world to celebrate the completion of the human genome project. An international consortium of scientists had collaborated for over 10 years, to determine the number and precise sequence of the nucleotides (the building blocks of DNA) that define the human genome. But whose genome was it? In fact we don't know! Since we are all more than 99.9% identical in terms of our genes: despite the ethnic diversity that we are all aware of, the human internet genome is a "composite" of 5 unknown individuals, selected at random from a group of approved (consent was provided) donors. I think we can all agree, that everyone is unique, with exception of identical twins. So how diverse is the human genome? What's more, what makes humans different from our nearest relatives on Earth? This is an important challenge for the Biologists among you. Just like the species richness method, you might want to think about how you assess the differences in numbers and types of genes. You might want to ask what characteristics make us visibly (or audibly!) different from our closest genomic relative? I'll give you a hint. How many primates have developed language skills? But there are other, even more obvious differences. What are they and what is their significance?

The human genome contains approximately 21,000 genes, spread over 23 pairs of chromosomes. For comparison simple bacteria, like E.coli have around 3,000 genes and even the fruit fly, Drosophila melanogaster, has around 10,000. There are some fundamental genes that we share with fruit flies, and even it seems with bacteria. How might you go about investigating this? Well the answer comes from computer science and I will be writing a post on this topic separately. I hope this might be of interest to those of you who are more computer minded. This is the field of Bioinformatics. And more on this soon. It is worth contemplating this. Humans represent less than 1% of the species on the planet and we only have twice as many genes as a fly. Bacteria (see below) are the second most abundant species on the planet, and they have on average one fifth the number of genes as a human.

Before I finish this post, I want to introduce you to the species that outnumber all of those I have discussed so far: microbes and their viruses (which we call bacteriophage).  In the news, we often read about bacterial pathogens, but most of the Earth's bacteria are found in the sea and the soil. It is estimated that there are approximately 4 × 10³¹ cells in total (4 with 31 0s after it!). Bacteria are often associated with humans and animals which provide many niche environments within them. By the time we reach adulthood, we are probably carrying around with us just under 1kg of bacteria every day! That's more individual bacterial cells than human cells in our own bodies. And that mixture is also diverse (see the above image)! And just as we are susceptible to the occasional viral infection, so to are bacteria. It is estimated that there are around 10 bacteriophage for every single species of bacteria. Making the bacteriophage the most abundant species of all, on planet Earth!

Next the diversity of languages. Have a good weekend!