o The Frog Blog: October 2008

Friday, 24 October 2008

Antonij van Leeuwenhoek

Dutch draper, biologist and microscopist Antonij (or Antonie) van Leeuwenhoek was born this day in 1632, in Delft in the Netherlands. van Leeuwenhoek made his own microscopes (see below) and was the first to discover and describe bacteria, protoctista and sperm. He was also the first to suggest that fertilisation occurred by sperm entering an egg cell. He was a remarkable man who became a fellow of the Royal Society of London and one of the leading scientists of his day – despite having no formal training.

van Leeuwenhoek’s father was a basket maker and his mother’s family were brewers. He went to school some 25 km north of Delft in the town of Warmond near Leiden, and was then apprenticed to a Scottish textile merchant in Amsterdam at the age of 16. It was here that he saw his first microscope – which was being used to examine the quality of fabrics. At the age of 22 van Leeuwenhoek returned to Delft and set himself up as a linen draper. Some ten years or so later it seems that he came across the work of English microscopist Robert Hooke, and this inspired him to use his microscopes to investigate the natural world. van Leeuwenhoek never wrote a formal scientific paper, but described what he found in letters to the Royal Society or to his friends. Despite his casual and conversational style of reporting, his observations were extremely accurate and he was careful not to confuse the facts with speculation. When he was 41 his observations of bee mouthparts and a human louse were published by the Royal Society, and three years later he became the first person to see bacteria. He was elected a fellow of the Royal Society in 1680.

Leeuwenhoek’s microscopes consisted of a single lens mounted on a brass plate, and he is believed to have made over 500 in his lifetime. Such instruments are not easy to use, and he must have coupled great technical skill with infinite patience in making his observations. His curiosity seemingly knew no bounds and he discovered parasitic protoctista (‘animalcules’) and spirochaete bacteria in a sample of his own faeces, and five different kinds of bacteria in his mouth. He died at the age of 90, on August 30th, 1723 in Delft.

Thursday, 23 October 2008

Ever Since Darwin by Stephen Jay Gould

American palaeontologist Stephen Jay Gould died of cancer in 2002, at the age of 60. Starting off in Antioch College and Colombia University (as did Edmund Wilson, see below), he spent much of his life at Harvard University, and was both a renowned researcher and a skilled writer and populariser of science.

His first collection of Natural History essays, Ever Since Darwin was published in 1977 and when I read it, at the age of 16 or 17, it had a profound effect. From then on I wanted to study palaeontology and evolution, and I learnt to value erudition coupled with clarity of expression in scientific writing.

The book consists of 33 unconnected essays, each just 6 or 7 pages long, and all on the theme of evolution and Darwin’s work. These were originally written between 1974 and 1977 for Gould’s regular column in Natural History magazine. Gould’s style is chatty and well informed, and he structures his essays in exemplary fashion. His general knowledge is wide ranging and he weaves music, literature, sport and history into his essays seamlessly, without ever losing sight of the central scientific thrust of each piece. His sixth essay, to take a fairly random example, is titled ‘Bushes and Ladders in Human Evolution’, and its start is typical of Gould’s style.
‘My first teacher of paleontology was almost as old as some of the animals he discussed. He lectured from notes on yellow foolscap that he must have assembled during his own days in graduate school. The words changed not at all from year to year, but the paper got older and older. I sat in the first row, bathed in yellow dust, as the paper crackled and crumbled every time he turned a page.’
Gould spent time working in Dublin, and amongst other things this led to his ninth essay ‘The Misnamed, Mistreated and Misunderstood Irish Elk’. If anybody were to read just one of the essays – to get a flavour of the book, then this would not be a bad place to start. The book starts with a look at Darwin the man and then, amongst other things, romps through human evolution, odd organisms, the zoology of size and shape and racism.

All in all Gould is a bit of a hero to me, and was a remarkable man who famously became involved in testifying against the compulsory teaching of creationism, and had a long running and at times acrimonious debate with (the slightly irritating) Richard Dawkins. Gould wrote a string of collections of short essays on natural history, and a marvellous book on the unusual extinct animals of the Burgess Shale in British Columbia (Wonderful Life). His last major publication The Structure of Evolutionary Theory, will shortly be hitting the Library’s shelves, and I look forward to reading it with great anticipation. Go on, give Ever Since Darwin a try!

For more information on the man himself, see http://www.stephenjaygould.org/original.html
Planet Earth Created on This Day in 4004 BC
From a study of biblical records, Archbishop James Ussher of Armagh (1581-1656) concluded that the Earth was created on this day in 4004 BC. In 1650 he produced a 2,000-page treatise which included the following:
"In the beginning God created Heaven and Earth, Gen. I. v. I. Which beginning of time, according to our chronologie, fell upon the entrance of the night preceding the twenty third day of October in the year of the Julian calendar, 710 (i.e. 4004 B.C.). Upon the first day therefore of the world, or October 23, being our Sunday."

Scotsman James Hutton (1726 – 1797) trained as a doctor but worked as an agricultural chemist and geologist. In 1795 he published his Theory of the Earth, which was based on uniformitarianism - the idea that the processes we see happening today are the same as they always have been, and that they alone account for all the geological activity which has shaped our planet. In suggesting this he dismissed the biblical timescale as being too short. When Hutton wrote about the vastness of geological time he summed things up nicely with the phrase "we find no vestige of a beginning, no prospect of an end". We now know, from radiometric dating, that planet Earth is around 4,600 million years old.

Wednesday, 22 October 2008

Earthquakes in Asia
In Asia alone over half a million people have been killed by earthquakes in the eight years of the 21st century. This disquieting fact is reported by James Jackson of Cambridge University – writing in Geology Today (Vol. 24, September-October 2008, p. 179).

The five most recent major Asian earthquakes occurred in: India 2001 (20,000 dead), Iran 2003 (40,000 dead), Indonesia 2004 (250,000 dead), Kashmir 2005 (80, 000 dead) and China 2008 (70,000 dead).
Earthquakes occur when the force of friction resisting movement between the rocks either side of a fault is overcome. Asian earthquakes tend to arise because of plate tectonics, as Africa, Arabia and India all push northwards into Eurasia.
The frequency of earthquakes which cause death tolls of more than 10,000 has risen to 1 every 2 to 3 years (compared with 1 per 5 years from 1600 to 1900). This does not mean that earthquakes are getting more common however, but reflects a rapidly growing population being crammed into relatively poorly built accommodation – such that each earthquake now has much greater potential to cause multiple deaths. This situation is coupled with a tendency for settlement to be attracted to earthquake zones due to faults causing transport corridors through mountainous regions, and because fault zones can create aquifers and springs in otherwise arid areas.
Improved building regulations in places such as Japan and California have shown that death tolls in earthquake zones can be greatly reduced through good planning and high standards of construction. Jackson concludes that if the number of earthquake deaths is not to rise greatly over the next few decades, there needs to be a marriage between geological awareness and political will and resolve in planning construction activity in the rapidly enlarging population centres which fringe the Alpine-Himalayan mountain belt. (JJS)

The May 2008 Chinese earthquake in Sichuan killed 70,000 people

Tuesday, 21 October 2008

On our recent trip to the Exploris aquarium in Northern Ireland, one of the most beguiling exhibits we saw was a cylindrical tank of little cuttlefish, who all seemed highly inquisitive as they looked out at us walking by.
Cuttlefish are molluscs (along with snails and oysters), and belong to the cephalopod group, which includes squids and octopuses. Cuttlefish are highly intelligent, with well developed eyes and green/blue blood (due to using copper based haemocyanin, instead of iron based haemoglobin to transport their oxygen). They are able to produce a cloud of ink (‘sepia’) when frightened to confuse any predators, and their internal skeleton consists of a calcium carbonate ‘cuttlebone’ which is often used by budgie and parrot owners as a source of calcium. These little animals are masters of disguise too, and can alter their skin colour at will.

Sunday, 19 October 2008

Edmund Beecher Wilson
American embryologist and cell biologist Edmund Beecher Wilson was born this day in 1856, in Geneva, Illinois. Wilson was prolific in his research output and, amongst other things, published on movement in Hydra, embryology of the earthworm and development in the marine worm Nereis and in amphioxus. In 1898 Wilson published a study which highlighted similarities in the development of embryos in different animal phyla, and thus concluded that molluscs, platyhelminthes and annelids must have a common ancestor. In 1905 Wilson published his work on sex determination by XX and XY chromosome pairings (also discussed by Nettie Stevens in a separate paper in the same year).
Wilson came from a long established New England family, and was reputedly descended from one of the officers of the Mayflower – which reached Cape Cod in Massachusetts from England in 1620. Wilson’s mother left New England with her family due to financial pressures arising from the economic crisis of 1837.
As a child Wilson’s great loves were natural history and music, and after a short spell as a schoolmaster he went to Antioch College in Ohio, where he was determined to devote his life “to biology or at least to science”. He found the teaching in Antioch to be good, but in 1875 moved to Yale – where he got a degree in Biology. Wilson moved to Johns Hopkins university in Baltimore, Maryland for three years, and then went to study in Cambridge University in England, Leipzig in Germany and Naples in Italy. On his return to the US Wilson spent time at MIT before moving to the newly established Bryn Mawr university in Pennsylvania, where he took charge of the Biology Department.
In 1891 Wilson spent another year in Europe (in Munich and Naples) before moving to Colombia university in New York. In Munich Wilson had met and been greatly influenced by the German embryologist Boveri (from Bamberg): “The best that he gave me was at the Cafe Heck where we used to dine together, drinking wonderful Bavarian beer, playing billiards, and talking endlessly about all manner of things”.

Saturday, 18 October 2008

Exploris Aquarium at Portaferry
by Alison Crampton (Form I)

1. The Touch Tank
On the 10th October 2008 we visited the aquarium in Portaferry, Co. Down. We learnt that there are two main groups of fish: bony fish (e.g. cod, haddock, turbot), and cartilaginous fish (sharks and rays). In the touch tank we saw: dog fish, bull huss, lesser spotted shark and thornback rays, which are all cartilaginous.
Sharks have existed for over 450 million years, and 65% of all known sharks are considered at risk. Sharks can come in many different sizes. Angel sharks grow up to 2 m long and eat: fish, crustaceans and molluscs. Angel sharks hide in the sand so no-one can see them. Angel sharks are most likely to be found in the Pacific Ocean because they only like warm water. Angel sharks have sharp teeth. The thornback ray (pictured above) is the most common ray. It has a long thorny tail and it can grow to be over 1 m long, and weigh up to 4 kg. Rays eat shrimps, amphipods, crabs and small fish.
Starfish have 5 legs. They are white and pink underneath and orangy red on top. Starfish are never found in fresh water. When you put clams beside starfish, the clams open up and move by squirting water out of their shells.

2. The Seal Sanctuary
Seals are often found around the coastline of Ireland. In Portaferry they bring in seal pups which are sick or abandoned. When they arrive in the seal sanctuary they are separated from the seals that are well and get put in sections with a light above their head. To get the seals to eat when they are young, the feeders stick a fish down the seal’s throat until they learn how to do it themselves. When they are older they get moved to a different area, and the seals that we saw were called Aero, Bounty, Crunchie, Munchie and Smarties. The grey seals have a long horse head face.

Form VI Biology Pupils Investigate Pulse Rates

Whatever the weather - the relentless search for truth continues!


Friday, 17 October 2008

A Short Description of the Life of Carl von Linne or 'Linnaeus'.
Carl von Linne was born in Smaland in South Sweden. He later took the latinised name Linnaeus. He was educated in Uppsala University, and began lecturing there in 1730 on the topic of botany. He published the first edition of his Systema Naturae in the Netherlands. He then returned to Sweden where he became professor of botany at Uppsala University. In the 1740s he was sent to classify animals, plants and minerals. This is known as taxonomy. He published several books. Also at the time of his return to Sweden, he settled in as a physician. He was the founder of the Royal Swedish Academy of Sciences. When not travelling Linnaeus worked on his classifications, extending them to the kingdom of animals and the kingdom of plants. He was the founder of the idea that animals should have an every day name and a scientific one too. He truly was the Father of Classification.
Jake Jacobsen (4th Form)

Whale Watching in Alaska

Over the summer, I had the opportunity to partake in a little Whale Watching in Juneau, the capital city of Alaska. The area is home to significantly large numbers of Humpback Whales, a beautiful animal, but one which generally lives its life alone, with the exception of a mother and calf. However, on occasion, in only six areas in the world (all in Alaska), Humpback Whales abandon their solitary life and co-operate in search of food. The result of such a collaboration is the phenomenon known as Bubblenet Feeding. A group of whales working together will dive under schools of herring, one whale will swim in a circle while blowing bubbles under the herring. When the bubbles rise they form a net and scare the herring into a tight ball in the center. The whales then come up through the middle with their mouths open, capturing large amounts food. An average group size is 5 to 8 animals and but I was exceptionally lucky to see 10 whales in the feeding frenzy. While they are searching for their prey the whales communicate with each other with a series of calls similar to the whale songs. These usually culminate with one loud blast to frighten the herring just before the whales break the surface. The captain of the boat dropped a hydrophone over the side to listen in, adding to the excitement of seeing this amazing performance. Here are some of the photos I took. My camera isn't great but it was one of the most amazing events I have witnessed.

Here's a quick pic of the amazing Hubbard Glacier, in Glacier Bay Alaska. The Hubbard Glacier is one of the only glaciers in the world that is actually growing. It is an impressive 122km long and when it meets the sea, is over 6km wide. It stands at a heights similar to a 20 storey building!

Girls and Science
The American feminist science education expert Nancy Brickhouse talks dismissively about the sort of science which is taught in our schools. She says that ‘western modern science’ (WMS) is inherently male-orientated, and that the acronym WMS should really stand for ‘white male science’.
Brickhouse feels that scientific knowledge is by its nature ‘gendered’, and suggests that, as a product of the 18th-century Enlightenment, WMS is based on dualisms (e.g. culture/nature, objectivity/subjectivity, reason/emotion, mind/body), in which the former member of each couplet is seen as masculine, and is more valued than the latter member – which is seen as feminine. It is implied that this automatically precludes girls from easily relating to science.
I wonder what DNA researcher Rosalind Franklin (pictured above) would have said about that - any thoughts?


Thursday, 16 October 2008

On the Nature of Physics

A physicist, an engineer, and a psychologist are called in as consultants to a dairy farm whose production has been below par. Each is given time to inspect the details of the operation before making a report.

The first to be called is the engineer who states: ‘The size of the stalls for the cattle should be decreased. Efficiency could be improved if the cows were more closely packed, with a net allotment of 275 cubic feet per cow. Also the diameter of the milking tubes should be increased by 4 per cent to allow for greater average flow rate during the milking periods.’

The next to report is the psychologist who proposes: ‘The inside of the barn should be painted green. This is a more mellow colour than brown and should help induce greater milk flow. Also, more trees should be planted in the fields to add diversity to the scenery for the cattle during grazing, to reduce boredom.’

Finally the physicist is called upon, who asks for a blackboard and draws a circle. ‘Assume the cow is a sphere . . .’

(Lawrence M. Krauss 1994, Fear of Physics p. 3)

Wednesday, 15 October 2008

Form I Science Trip to Northern Ireland
On Thursday 9th October 2008, the entire First Form headed off to Northern Ireland for a three day science trip. The American cross-gender school soccer classic She’s the Man, provided the on-board entertainment as we headed through the rain towards Armagh Planetarium – our first port of call. There we saw a film presentation on being an astronaut, built and then flew our own rockets (made from old Coke bottles and sticky tape), and viewed exhibitions covering all aspects of space exploration and planetary science.
After a hurried packed lunch it was time to head for a rainy Castle Espie, on the shores of Strangford Lough, where an introductory talk emphasised the global importance of our wetlands, and we were introduced to the different types of wildfowl (ducks, geese and swans). We stood in the rain and fed various diving-ducks with their distinctive rear-ended legs (e.g. the red breasted merganser and tufted duck), and dabbling-ducks such as mallards, pintails and wigeon. Then, out on the mudflats, there was a chance to view brent geese - just arrived from Greenland and Canada via Iceland. At Castle Espie we also saw the early stages of a building project involving recycled materials and energy-efficient design.
Finally it was time to cross on the ferry from Strangford to Portaferry, where the good ladies of Barholm Hostel had our supper ready and waiting. After supper a 45 minute review session finished off a long but varied day.
Day two dawned grey and rainy, and after a pleasant cooked breakfast we strolled along the lough shore to the new tidal energy plant, and had a brief introduction to the geology of the area. We then walked around the corner to the Exploris aquarium, where we were introduced to various marine animals in the ‘touch-tanks’ - followed by a guided tour around the excellent aquarium and seal sanctuary.
After lunch it was off to the Ulster Transport Museum for a ride in a flight simulator, and a tour of the various exhibits, which allowed a questionnaire to be filled-in. The rain still fell as we had supper and once again we rounded off the day with a reflection and review session – focussing on how to plan the project work based on the trip.
On Saturday morning, somewhat confused by the lack of rain, we bade farewell to Barholm and drove into Belfast to the vast hands-on science experience that is ‘W5’. There we also visited a dinosaur exhibition with animated life-size models complete with steaming piles of dung! After a final Lagan-side packed lunch it was time to head wearily south once more and return to Dublin. All in all it was a great trip, and we’ll post some of the completed project work shortly.
JJS and KH

Friday, 10 October 2008

Here are some photos of the 5th Form Agricultural Science trip to the National Ploughing Championships in Kilkenny in September.