Snippets

Published 13/12/11

Alan Turing, genius

If you mention the name Alan Turing, I dare say most people think immediately of the genius behind the cracking of the cipher codes of the Enigma machines or the creator of the virtual Turing machine.

What many people do not realise, and the reason why this piece is appearing in Indigenotes, is that Turing wrote a seminal article, titled “The Chemical Basis of Morphogenesis”. Published in 1953, just a year before Turing’s untimely death, the paper uses reaction-diffusion equations to identify pattern formation.

Morphogenesis is the biological process that causes an organism to develop its shapes (from the Greek, literally meaning “beginning of the shape”). Turing’s central interest was the presence of Fibonacci numbers in plant structure and specifically phyllotaxis - the spiral patterns found in plants based on the Fibonacci series.

Any organism starts out as a single cell but can develop into a complex entity comprising trillions of cells and, for example, in the case of a human being some two hundred different types all cooperating to perform complicated functions. Turing was interested, not so much in the later stages of development of the cells, but in how the process becomes established. The paper proposes that the answer lies in the bifurcation properties of the solutions of simple differential equations. There can exist a value that when approached becomes critical and what was previously a stable solution becomes unstable. An example of this is the sudden collapse of a beam as it overloaded.

Using relatively simple mathematics and chemistry, Turing constructed a model such that by simply varying a chemical substance one can obtain a predictable and defined pattern.

The paper comprises two ideas. One, patterns can appear from simple differential equations at the point of instability. Moreover, the equations determine both the shape and the pattern. Turing demonstrated that the model holds regardless of whether the region is divided into cells or not.

In the midst of producing this outstanding work, Turing’s personal life was in tatters. Turing was homosexual and when his relationship with his partner soured, the partner broke into Turing’s house. Upon reporting the incident to the police, instead of following up the break in, Turing was charged with gross indecency. Found guilty, he was given the choice of prison or chemical castration (by injections of oestrogen – the ‘enlightened’ solution of the time). Turing chose the latter but on 7th June 1954, suffering depression, he took his own life by eating an apple laced with cyanide, just two weeks before his 42nd birthday.

In 2009, Gordon Brown issued a public apology and now, marking the centenary of his birth in 1912, there is an epetition requesting the British government to pardon Alan Turing for the conviction of gross indecency. Unfortunately, the petition is only open to people who have British citizenship, however I urge all members who qualify to consider signing. http://epetitions.direct.gov.uk/petitions/23526

– Lawrie Hanson


IFFA’s propagation workshop

On a hot and sultry Saturday morning, eleven IFFA members and ten non members braved the elements at the VINC site in Fairfield and were extremely well rewarded by a thoroughly engrossing workshop on the propagation of indigenous plants given by Judy Allen.

Judy commenced by discussing seed treatments. These included the boiling water method and applying sandpaper to the seeds with thick coats. She then moved on to seeds that germinate best at high temperatures and some that require exposure to a temperature under three degrees Celsius. She concluded the seed handling section with discussion of the bog and smoke treatments. As she pointed out, you have to think in terms of what is happening to the seed in the natural environment, for example, going through a bird’s gut. She also highlighted the importance of ensuring genetic diversity.

We then moved on to the two methods of sowing. The first by successive transfers from trays to tubes and so on; and the second via direct sowing which is the preferred method in many cases. I was intrigued to discover what is termed “J rooting”. This is when a plant forms an S bend in the root and hence develops kinks that impede the flow of water and sugar. A plant version of “arterial sclerosis” develops and eventually circulation is cut completely and the plant dies. All this happens below ground and it is only when the plant keels over usually unexpectedly that you realise something was amiss.

Judy concluded the workshop with a discussion of propagation by cuttings. This included a hands on component for each of us where we stripped off all but the top 4 to 6 leaves of a cutting. Judy then showed us how to prepare the cutting by dipping it in hormone and then placing in a pot. For those that missed the event, there is still an opportunity to obtain a copy of Judy’s DVD Seeding the Future which is about seed collection and cleaning, but doesn’t go into propagation.

The event was extremely useful and enjoyable with a good range of questions expertly answered by Judy. If there are further questions from IFFA members, Judy has kindly offered to respond. You can contact Judy at allenjude@hotmail.com It is planned to create an FAQ on the IFFA website of the questions and responses.

Thanks once again to Judy and also to Fam and Linda for organising the event.

– Lawrie Hanson


Is your favourite species threatened?

Nominations are due by 22 March.

Threatened species and ecological communities listed under the Environment Protection and Biodiversity Conservation Act 1999 are protected and there is now the opportunity to extend this protection.

The Federal Government is calling for nominations from the community for new listings of threatened species, ecological communities or key threatening processes. Nominations are invited for any species, ecological communities or key threatening processes to be considered for listing under national environment law. The conservation theme for this assessment period is corridors and connecting habitats (including freshwater habitats), but nominations outside the theme will also be considered.

See: http://www.environment.gov.au/biodiversity/threatened/nomination Environment Defender’s Office


Tertiary student volunteers

The Environmental Volunteer opportunities table is designed to provide tertiary students with a resource they could use to look for activities and organisations that could further their knowledge, skills and experience in environmental areas. It is available on the IFFA website (http://www.iffa.org.au see the box on the right hand side of the home page). The table is structured to clearly outline different activities so interested people can easily find one to suit their location, availability and interest. Activities include friends groups plantings, propagating, weeding and bird surveys.

To produce the table, IFFA member organisations were sent a letter with a follow up phone call and asked if they had any volunteer opportunities they would like to be included. However the table is not exclusive to IFFA member organisations.

It is a work in progress and anyone can contribute. If you would like to have your organisation represented, please email me with the following information: type of work, time, description, requirements, location and contact.

– Karen McGregor, student representative, student@iffa.org.au


Skin prices in 1889

The Argus, Melbourne Friday 28 June 1889.
From the Australian Mortgage and Agency Company Report

“Furred Skins — Large supplies of these goods are arriving daily. Wallabies and forester kangaroos have maintained their value throughout the month, while wallaroos red and blue skins, and brush sorts are much weaker. Opossum skins were easier last week, but at the auctions to day the fall was fully re-covered. Rabbit skins have risen in value while a slight decline is now noticeable in Native bears. All other descriptions unchanged. Quotations to-day are:

  • kangaroo, best forester grey to 2s. 4½d. per lb., average to good forester grey 1s 3d to 2s. per lb.
  • wallaroos, large 1s. 4d. per lb nominal; medium 11d. to 1s. per lb , red large 1s. to 1s. 3d. per lb.; small, 6d. per lb.;
  • brush, superior, 1s. per lb.; Inferior, 6d. to 10d. per lb.
  • Wallaby, small 4d. to 8d. per lb. , medium to good, 10d. to 1s. 6d. per lb.; superior, to 1s. 8d. per lb.
  • Opossum skins poor to fair, 1s. 6d. to 4s. per dozen; good 4s. 6d. to 8s. per dozen; superior, 9s. to 11s. per dozen;
  • mountain, 12s. to 20s. per dozen;
  • Rabbit skins, small to fair, 4d. to 9d. per dozen; good 10d. to 1s. 2d. per dozen; superior, 1s. 3d. to 1s. 6d. per dozen , extra weights, higher.
  • Bear skins inferior, 2s. per dozen; best, 4s. 6d. to 5s. 6d. per dozen.
  • Native cat skins, black, to 4s per dozen, grey, to 2s. per dozen; tiger, to 8s per dozen,
  • domestic cat skins, ordinary, 3s to 6s per dozen superior, to 8s per dozen,
  • Water rat skins superior, 3s per dozen,
  • Platypus skins, good to superior, 18s to 36s per dozen”

It would make an interesting student project to compile reports such as this and look at price trends over time, relate this where information is available on quantities traded, and to known extinction dates, compare prices to current values etc.