ITV’s three-part television series on London and Whipsnade Zoos has just ended. It was, of course, as dumbed down and as superficial as one would expect of ITV at 8.00 pm. However, what the Zoological Society of London (why was it 'Zedessell' with every breath?) clearly saw as an exercise in free publicity seemed to me to backfire.
Zoology has a discipline: evolution; zoology is vertically integrated, concerned with biological organisation at the level of organisms in their environment, organs, tissues, cells and molecules. This blog meanders through the animal kingdom, from aardvarks and anoles, through mouse and man, to zorillas and zebras.
Sunday, 28 July 2013
ITV’s The Zoo: An Own Goal for The Zoo?
ITV’s three-part television series on London and Whipsnade Zoos has just ended. It was, of course, as dumbed down and as superficial as one would expect of ITV at 8.00 pm. However, what the Zoological Society of London (why was it 'Zedessell' with every breath?) clearly saw as an exercise in free publicity seemed to me to backfire.
Labels:
London Zoo
Friday, 28 June 2013
Biological Systems: Is Redundancy Redundant?
The term redundancy is often used to describe two or more processes in biological systems that appear to do the same job. The term has been borrowed from Information Theory. The definition in Wikipedia is as useful as any:
Redundancy in information theory is the number of bits used to transmit a message minus the number of bits of actual information in the message. Informally, it is the amount of wasted "space" used to transmit certain data.
I have never been comfortable with the term in biological systems except in discussions on signalling systems (endocrine, autocrine, paracrine, intracrine) where it can be used in its proper, Information Theory, sense‡. My qualms on using it for biochemical pathways and membrane transport systems, for example, are that it has implications of a mechanism being present but not needed. I have argued in the past that parallel pathways and different transport mechanisms carrying the same substrate are better described as safety mechanisms (belt-and-braces adaptations) or as systems that may be used in some circumstances and not others.
The other problem in using the term is that it can be confused with redundancy in the evolutionary sense, a vestigial character for example. I sometimes think we should leave the term in its more usual English meaning of superfluous in the hands of human resource departments, those parasitic forms of life, to apply to themselves. Auto-redundancy in these anti-personnel departments† would do more than a little to aid economic recovery — and benefit science, technology and engineering.
Bacteria often possess multiple siderophore-based iron uptake systems for scavenging this vital resource from their environment. However, some siderophores seem redundant, because they have limited iron-binding efficiency and are seldom expressed under iron limitation. Here, we investigate the conundrum of why selection does not eliminate this apparent redundancy. We focus on Pseudomonas aeruginosa, a bacterium that can produce two siderophores—the highly efficient but metabolically expensive pyoverdine, and the inefficient but metabolically cheap pyochelin. We found that the bacteria possess molecular mechanisms to phenotypically switch from mainly producing pyoverdine under severe iron limitation to mainly producing pyochelin when iron is only moderately limited. We further show that strains exclusively producing pyochelin grew significantly better than strains exclusively producing pyoverdine under moderate iron limitation, whereas the inverse was seen under severe iron limitation. This suggests that pyochelin is not redundant, but that switching between siderophore strategies might be beneficial to trade off efficiencies versus costs of siderophores…
So, how many apparently redundant mechanisms can really be described as such? Perhaps we really should confine it to its proper use in signalling systems where redundancy in the message decreases the error in transmission.
* Proceedings of the Royal Society B 7 August 2013 vol. 280 no. 1764 20131055
† Sir Barry Cross’s loudly whispered description in the early 1980s of the personnel department of the old Agricultural Research Council (later AFRC, now BBSRC)
Labels:
Information Theory,
Redundancy
Sunday, 23 June 2013
Donors of Reptiles to London Zoo 1914/15: 8. Herbert Tomlin Pollitt
Again, and nearing the end of this series of posts, this is what Clin Keeling wrote in A Short History of British Reptile Keeping:
H. Pollit of 7 Grosvenor Road, Handsworth, Birmingham, gave an Alligator, an Eyed Lizard and a European Pond Tortoise…
Thanks to a search of the 1911 Census, a family history on ancestry.co.uk and the keeper of that history, Any Pollitt, I have identified this ‘H. Pollit’ as Herbert Tomlin Pollitt. He was born in 1897 in Irlam, Lancashire. In 1911, aged 13, he was living at the address shown in the Zoo’s records. His father, a chemist, was manager of a soap works; he worked for Lever Brothers (now Unilever).
Tuesday, 18 June 2013
Blue Poison-Dart Frog: The Times Gets It All Wrong
The Times really should check its sources and material before publication. Today’s edition has a short article that states:
British scientists have successfully bred a rare species of frog that contains enough poison to kill up to ten adults. The blue poison dart frog, which is 2.5cm long, is found in the tropical forests of Costa Rica and Brazil. Experts at Walford and North Shropshire College have successfully bred one in their laboratory…
In 1970 I returned to the Sipaliwini savanna on another expedition and at that time I collected 10 specimens of D. azureus from the Vier Gebroeders forest island, and transported them alive to Holland, where they formed the basis of the first, and only legal, breeding colony of D. azureus. All other colonies were established with smuggled specimens, from which the present specimens in captivity are descendants1.
This species breeds easily in captivity, and is found in zoos around the world.
The reason for my writing about this claim here is to highlight a common and growing problem. Zoos and wildlife collections are forever putting out press statements that they have bred such-and-such and that it is ‘endangered’. Such claims are rarely true and even when it is correct that the species in question is endangered, or in some other less than safe category in the wild, there are often so many in captivity that zoos do not know what to do with them. Not only do such silly or trivial claims play straight into the hands of members the anti-zoo lobby who know a false claim when they see one but detract from the hard-earned achievements of those involved in ex-situ conservation.
I now expect to see reports that such and such an organisation has bred axolotls — critically endangered in the wild. I shall probably read the report while drinking coffee in Dobbie’s Garden Centre, yards away from tanks containing axolotls at £22 each.
Wednesday, 12 June 2013
Donors of Reptiles to London Zoo 1914/15: 7. Bernard Tucker and William Waldegrave
Again, in this series of posts, this is what Clin Keeling wrote in A Short History of British Reptile Keeping:
Mr. W.B. Tucker of Hillside, Harrow on the Hill, Middlesex, got rid of a Brazilian Tortoise, a Spanish Terrapin and a Scorpion Mud Turtle (this latter one of the Box Turtles), and I was intrigued to discover that a few months later he sent, from Chewton House, Chewton Mendip, near Bath, two Radiated Tortoises, a Rough Terrapin (!) and three more Scorpion Muds on behalf of Lord Chewton. Was the latter, I cannot help wondering, an earlybut self-effacing practical herpetologist who had persuaded Mr. Tucker, who he knew to be similarly-minded, to come westwards in order to look after his collection - some surplus of which he decided to donate to the Zoological Society of London?
![]() |
| Bernard Tucker |
An account of Bernard William Tucker’s life was written by David Lack. Originally published in Ibis in 1951 it was reproduced in his book, Enjoying Ornithology (Methuen, 1965). I can do no better than to quote from it:
With the death of Bernard William Tucker on 19th December 1950 after a long illness, British ornithology loses it central figure. This position Tucker had come to fill, in characteristically unobtrusive fashion, partly through the width of his interests, which ranged from the identification of rare waders to the physiology of feather-growth, and particularly through his varied services to ornithology. He was Reader in Ornithology at Oxford University, Editor of British Birds, a former Vice-President of the British Ornithologists’ Union, and Vice-Chairman of the British Trust for Ornithology.
Born on 22nd January 1901, at Northaw in Hertfordshire, Tucker spent most of his boyhood at Chewton Mendip in Somerset; and his first publication was on the birds round Chewton Mendip in the report of the Wells Natural History and Archaeological Society in 1918. He was educated at Harrow School, where he won the Lord Claud Hamilton Biology Prize in 1918 and the William Roundell Leaving Scholarship in 1919. He went up to Oxford in 1919 with a demyship (senior scholarship) at Magdalen College, and obtained 1st class honours in Zoology in 1923. He then obtained the Oxford scholarship to the Stazione Zoologica at Naples, where he worked on parasitism in crustacea for a year, paying later brief visits to Naples in 1925, 1927 and 1928. At Naples, also, he met his future wife, Gladys Allen, whom he married in July 1925. In the same year he was appointed a Demonstrator in the Zoological Laboratory at Cambridge, Professor Stanley Gardiner’s intention being that he should fill Gadow’s place as lecturer in vertebrate anatomy. When Gadow unexpectedly postponed his retirement, Tucker in 1926 returned to Oxford under Professor Goodrich, and he became a University Demonstrator and Lecturer in Zoology and Comparative Anatomy in the following year. This post he held for the rest of his life, becoming Browne Research Fellow of the Queen’s College 1944-47 and Reader in Ornithology in 1946.
Tucker once told me that he differed from most ornithologists in that he did not develop an overriding interest in birds until unusually late, about his eighteenth year. At school, botany had been a major interest, and as an undergraduate he was noted for the variety of reptiles and amphibia which he kept in vivaria in his rooms….
In the zoology department at Oxford, Tucker lectured mainly on the vertebrates, including of course the birds, and he was one of the first in Britain to supplement the orthodox lectures on anatomy with others on habits, including migration. He was noted for his skill both in dissection and in anatomical diagrams, some of the latter being published in De Beer’s Vertebrate Zoology, which became a standard textbook for students…
Tucker has had an extremely important influence on British ornithology in three different ways, through his work with local ornithological societies, through his work on field characters, particularly as published in the Handbook of British Birds, and through his work for the Edward Grey Institute at Oxford…
In B.T.O. affairs, however, Tucker’s greatest service was at Oxford, for he, more than anyone else, was responsible for getting University support for the Institute…
Tucker would have been 13 when his gave his chelonians to London Zoo. Were they too difficult to keep at school?
*http://bit.ly/17GJmex
Labels:
Clinton Keeling,
London Zoo,
reptile
Tuesday, 11 June 2013
Birds and Light Pollution: Hong Kong at Night
A correspondent in Hong Kong writes:
If you are in the centre of Causeway Bay at the Sogo crossing around 9pm it is dark, but swallows are still feeding by hunting insects that are attracted to the large illuminated advertising hoardings. So yes they are still feeding and getting the extra food while their less urbanised relatives sleep.
Labels:
Hong Kong,
light pollution
Thursday, 6 June 2013
Blackbirds and Light Pollution. A Man and his iPhone App at Dusk and Dawn
Passers by may have thought it a little odd. It is not every day they see a man crouched under bushes in the garden at dusk clutching an iphone. The reason for this madness was that I was intrigued by a paper* in Proc. Roy. Soc. on the effect of artificial light at night on reproduction in birds.
*Artificial light at night advances avian reproductive physiology. Dominoni, D, Quetting, M Partecke, J. 2013. Proc. R. Soc. B 280, 20123017.
Subscribe to:
Posts (Atom)
+-+Version+2.jpg)
