Monday, February 23, 2004
Eucalypt Leaves and Water
A couple of times recently, I have noticed how well eucalypt leaves repel rainwater. Small droplets of water form on the surface of the leaves but the leaf as a whole does not get wet. I suppose this is due to the waxiness of the surface.
suggests that some plants avoid disease by repelling water:
" Why would plants evolve water-repellent leaves? To prevent sickness, say the scientists. They found that water-repellent leaves are also self-cleaning leaves: dirt particles on the leaves adhere more strongly to the water droplets than to the leaf surfaces, and so are washed away when water hits the leaves. The scientists conjecture that dirt, which also contains the spores and conidia of disease fungi, is also washed away. And because water cannot adhere to the leaves, any disease organisms that are on the leaf, since they require water for germination and growth, simply cannot survive to infect the leaf. "
This article is referring to plants in wetland environments. I wonder if the same disease-prevention effect of repelling water might apply in the case of dryland plants like eucalypts.
Of course, in the case of eucalypts, this water-repellent tendency might simply be a side-effect of having a strong waxy coating on the leaves so as to prevent water loss in a dry climate. However, some useful protection might also be afforded against fungal attack.
Wednesday, February 18, 2004
Australian Natural History at Its Best
I have been meaning to write about two new productions from noted Australian naturalist Trevor Hawkeswood. Trevor is an incredibly prolific biologist, specialising mostly in entomology.
I have mentioned Calodema before. This is his new journal: "An Australian biological journal devoted to promoting knowledge about the flora and fauna of Australia and the Pacific".
As time goes by I shall update this post with more information on this journal. Suffice it to say that it is a good read - and a nice looking production with the jewel beetle on the cover. One of the most significant papers would be Turner and Hawkeswood's description of a new jewel beetle from the Sydney Basin, New South Wales, Australia, Melobasis jacquelinae
sp. nov. An entertaining critique of another entomologist's work on an Australian genus of rove beetle, Stenus
, is a good example of Hawkeswood's swashbuckling style.
The other item is Trevor's "Spiders of Australia: An Introduction to their Classification, Biology and Distribution". This book
was published by Pensoft, in Eastern Europe, but there is nothing wrong with its production values. It's a fine looking volume (mine's the hardcover version). I was a little disappointed when I first opened it, because I assumed that the little black-and-white thumbnail illustrations in the main part of the book were all you got: then I realised that they were simply pointers to the plates at the back, which are excellent.
At first blush the written content looks fine. With Trevor, you get original observations, real cutting-edge stuff. The book deserves success, and should encourage much productive follow-up work by other biologists. It would be an ideal volume to give as a present to an intelligent young person with an interest in nature.
Overseas readers will likewise be intrigued. Australia is still terra incognita
in many ways, biologically speaking. For example, I was delighted to read of the obscure member of the "daddy long-legs" family (Pholcidae): "Trichocyclus
is a monotypic genus from the semi-arid districts of central Western Australia. Nothing appears to have been written on its only species, T. nigropunctatus Simon 1908, since it was first collected from Yalgoo near the turn of the 20th century."
I was interested to see that the "daddy long-legs" spiders are simply treated as another family. I have always told my daughter, who is scared of these spiders, that they are not really spiders at all, in the true sense. It seems that they are.
Monday, February 16, 2004
The Value of Left-Handedness
It seems that left-handedness was as common in the Ice Age as now. This article
" Left-handedness may have conferred prehistoric man advantages, such as in combat, say the researchers. "
If left-handedness did indeed confer benefit in combat, it might have been because of the "surprise value" of having to fight a left-hander. Since such a surprise value would only be effective if left-handedness were relatively uncommon, this might explain why it is found in only a quarter of the population, or less.
That is, there would seem to be an optimal level of occurrence of left-handedness. If it were too common it would lose its survival value. Some traits are like that. It is called (negative) frequency dependent selection
The article claims that handedness is partly under genetic control. So it seems feasible to me that left-handedness is an example of a trait that is maintained in the human population because it is useful to people who have it, provided it does not become too common.
How much of an advantage is it to be a left-hander in a fight? I am not aware of any systematic studies, but people who write about boxing in America refer to "southpaw [left-hander] advantage". An example
" And his southpaw advantage shouldn't be minimized, Ayala said.
"I know Bones has faced some southpaws, but I'm an extremely good southpaw," Ayala said. "I'm not a walk-in-the-park southpaw."
Wednesday, February 11, 2004
I recently watched "Unbreakable", which stars black actor Samuel L Jackson and Bruce Willis. Here
is a review.
The Director - M Night Shyamalan - achieves his trademark trick ending by using political correctness against the viewer. We simply don't even consider that a disabled black character, with a loving mother, could be evil.
Very clever - and I wonder if we shall now see a string of films that use political correctness to surprise us.
Tuesday, February 10, 2004
One thing that I like is finding that books in my library "know each other". That is, that they refer to one another. For example, I found that a book I recently acquired on Jewish "angel magic" contained references to two other books I own: Moshe Idel's "Golem" and a book by Meyer and Smith on "Ancient Christian Magic".
Another recent example was finding that a book on Jews in 19th Century Egypt is cited in a bibliographic book on Judaism I also own. This makes me feel that both books are "kosher", so to speak.
Monday, February 09, 2004
Last night the ABC showed the first in a series of nature programs about Australia. They are actually a production of BBC Bristol. Quite good, if a little over-familiar to an Australian audience. But some new insights. While watching it, my wife and I got onto the subject of flightless birds. I started to say that many flightless birds grow to large sizes, a fact that I had always assumed was related to the need to achieve the protection against most predators that goes with bulk. Where there were no original predators, flightless birds often remained small - dodos for example.
But then I thought of New Zealand where there were both small and large flightless birds - kiwis and moas. Assuming there were no predators on New Zealand (until man and the pest animals he brought arrived), why did moas grow so big?
Obviously here is a topic worth researching, at least in books. I wonder how the giant flightless bird, Aepyornis (spelling?) fits in?
Wednesday, February 04, 2004
I popped in to the Australian National Gallery at lunchtime today. No entrance fee is payable to access the bookshop, which has quite a good selection.
After a thorough look, I picked up a copy of the "Romanesque" volume in an architecture series published by Feierabend. I already have the "Baroque and Rococo" volume in this series, which is really excellent. I also bought Robert Powell's "The New Thai House" because I was looking for something on architecture in hot climates. I have seen some excellent books on architecture in the Phillipines, but this is the first book on "tropical" architecture that was cheap enough.
Anything I collect must be fairly inexpensive. So my idea of collecting fishing lures may be feasible. I found two that appealed to me aesthetically and functionally on our recent trip to Jindabyne - at a place called the Snowy Valley Service Centre - which were only about four dollars each.
The Economics of Fantasy
asked a good question, the sort that troubles me:
" ... on what did the men of Rohan base their economy, since no cultivated fields nor mines nor factories are to be seen anywhere near their hilltop fastness? "
This is not the only economic conundrum posed by "Lord of the Rings". I have never liked Tolkien's epic much. I remember being puzzled and irritated by a description of a metal called "mithril":
"Mithril! - all folk desire it ... a coat of chain mail made of mithril is worth more than all the wealth in the Shire ... etc. etc."
Or something like that.
What kind of economics is this? The Middle Earth equivalent of titanium - enough to make a protective suit - is supposed to have the same value as all the land and goods in the Hobbits' shire. Really??
Msgr Ronald Knox had a lot of fun inventing the game
of analysing the Sherlock Holmes stories as if they were historical documents to be subjected to detailed scholarship. Perhaps someone should analyse the economics of Middle Earth likewise - I imagine the results would be as amusing.
Public service message
Remember: a puppy is not just for Christmas: they taste good at Easter too.
Tuesday, February 03, 2004
We went as a family to Candlemas
last night at the Classical Roman Rite (Latin Mass) community location at Ss Peter and Paul, Garran, here in Canberra.
We arrived a little late so our candles did not get put into the sanctuary for the liturgical blessing. They were blessed after Mass though - in all their not-very-canonical colours and shapes (a round turquoise one, a sort of oblong pink one with stars). Still, they are blessed.
The liturgy celebrates both the Purification of the Blessed Virgin Mary and the Presentation of Our Lord in the temple. There is a great deal of "light" imagery and the procession with lit candles recalls the journey of Mary and Joseph to present Christ in the temple.
There is a pleasant reference to the wax of the candles being the result of "the labour of bees" in the Latin text, which is one of those rare zoological moments in the liturgy that seem so delightful.
has more on Candlemas.
Monday, February 02, 2004
There were two excellent documentaries on ABC and SBS respectively last night. The first was on a chap running a sort of cult video shop in Brisbane. The ABC one was on rhinos. As one gets older, it becomes rarer to hear something completely new, so I was pleased to be told that rhinos were used in the past in warfare in India, including rhinos with javelins attached to their noses. I suppose they were the "shock and awe" weaponry of their time.
I had heard of the use of elephants in battle, but not rhinos.
The rhino documentary included some remarkable footage of a white huntress standing her ground as a rhino charged, and shooting it down. This reminded me to read my copy of "Lion-Hunting in Somali-Land: Also, an Account of 'Pigsticking' the African Wart Hog" by C. J. Meliss. Captain Melliss as he was then - he rose to a high rank and won the Victoria Cross if I remember correctly - had quite a good prose style. He writes of shooting an oryx for its meat and of how he had to ensure that it was killed in an halal style to make it acceptable to his Somali men, who were Muslims. He had to cut its throat to kill it, which must have been messy and dangerous given its horns. I suppose this
shows what the oryx - and the country - looked like that Melliss hunted.
I haven't finished the book yet, though I've dipped into both sections. There are more illustrations - including black and white photographs - in the section on lion hunting than in the section on "pigsticking" warthogs. Some of the pictures of dead lions and lionesses, heads and skins, have a kind of hysterical grossness about them. Still, it's fascinating stuff of its kind.
My copy of Melliss wasn't cheap, even though it is only a facsimile in a series put out by Peter Capstick. But books are easier to buy than CDs. I find it easier and less fussy to sample a book quickly before you buy. It also seems to me that one's positive or negative reaction to music is much more dependant on one's mood at the time. I am learning to be suspicious of music reviews, particularly at places like Amazon.com's website. I suspect the dynamic might be that somebody buys a CD, it happens to appeal to him strongly and he is moved to write a review on Amazon. Up it goes: "This is the most moving music I have ever heard." One has to allow for hype and also that typically American salesmanship.
My daughter was perusing descriptions of furby toys on sale on eBay recently. They were all claimed to be unique bargains. I had to explain to her about American salesmanship. It is almost inborn.
Some of the sacred music CDs I have bought recently have been OK, but nowhere near as impressive as their reviews on Amazon would imply.
As to books, I acquired three yesterday: on the search for the North-West Passage (great charts of the futile searches); on the endangered Spix' macaw (continuing my interest in macaws and parrot colours in general, blogged earlier); and a book by the prolific Simon Winchester on the making of the first geological map of Britain.