What Have The Romans Ever Done For Us…

Work done by Dr Nikola Koepke (formerly from Oxford University but now at Zurich Universtory) looked at the remains of skeletons from the 8^th century BC until the 18^th century AD and used changes in people’s heights over this period as a measure of how well fed they were. The study combined biology and archaeology and concluded the following…

• Contrary to popular belief, the Roman Empire resulted in reduced not enhanced living conditions. People’s general nutritional status decreased with Roman occupation.
• There was no ‘Dark Ages’. With the decline of Roman supremacy, living conditions for the overall population improved.
• Even prior to the Industrial Revolution, average human height increased by roughly half a centimetre every 1,000 years.
• Urbanisation fails to improve wellbeing, as measured by height.
• Consumption of milk is the key factor behind significant regional differences in average height between Mediterranean and Northern Europeans.

So it looks as though Roman occupation did not lead to a higher standard of living for the natives of the occupied countries. This piece of information gives me license to post the following informative video clip!

Dr Koepke was able to relate milk consumption to height by using a proxy. A proxy is a set of data that can be used to infer an effect that cannot itself be measured. In this case, it is possible to estimate the ‘cow share’ of the population. This means the number of cows per human being. In towns there is a high population of people and therefore a low ‘cow share’ so average milk consumption must be low. In rural areas where the ‘cow share’ is higher, each individual would have greater access to milk. Amongst the many factors she compared with changes in height, the most significant relationship was between ‘cow share’ and height. This is why she is confident to say that our ancestors who drank lots of milk grew taller than those who did not.

Science uses statistics to check if there is a ‘significant’ relationship between one factor and another. Sometimes the patterns cannot be seen until they are analysed mathematically. A good example is smoking and lung cancer. It may seem obvious now that smoking increases the risk of lung cancer. It was not obvious sixty years ago until all the possible risk factors were compared with incidences of lung cancer and the strongest mathematical link (a significant link) was seen for smoking.

About 75% of the world’s adult population are lactose intolerant meaning they cannot digest lactose, which is the sugar found in milk. Lactose is too large a molecule to be absorbed into the blood in the small intestine and so travels into the large intestine. Here it gets attacked by bacteria and is turned into hydrogen, methane and carbon dioxide. This leads to bloating and discomfort. People with lactose intolerance do not produce lactase, which is the enzyme that can split lactose down into glucose. Only about 5% of adults in Northern Europe are lactose intolerant but this increases to about 99% in many parts of Asia and Africa.

The video below shows an experiment you can try at home with whole milk (not semi-skimmed), some food colouring and a cotton bud with some washing-up liquid soaked into the cotton wool. If you do try this, photograph the results and email them to me so that I can put them up on the site.

Questions…

1. What is an enzyme?
2. What mineral does milk contain and why is it important in our diet?
3. What role does your large intestine play in the digestive system?
4. What are the chemical tests for a) hydrogen and b) carbon dioxide?
5. Which ethnic group has the highest percentage of lactose intolerant members?

Another example of using proxy data is the use of stalagmites and tree ring data in climate research.