Australian Bioscience News & Views

Life is parasitic

Genes and memes are selfish replicators, and the very convoluted nature of it all is highlighted nicely by the example of how the "green things" were assimilated. I don't mean "little green men", I mean how plants and algae got their chloroplasts. Chloroplasts are the tiny, membraneous balls within the cells of photosynthesising organisms that do the actual work of converting sunlight to chemical energy.

On several different occasions, larger cells "trapped and enslaved" these tiny sunlight-powered workhorses and put them to use feeding larger and larger structures.

This view of life is an interesting, almost negative take on The Goldilocks Enigma proposed by Paul Davies. On the other hand, it might be more apt to consider the example of one type of cell engulfing another as a kind of ultimate example of natural selection resulting in novel solutions to the basic problems of life, such as the need for energy.

European giant

While apparently it doesn't quite compare to the South American behemoths, the new Spanish sauropod contender for largest European ever is Turiasaurus riodevensis, and at 38 metres in length it seems impressive.

Of course, as Glenn pointed out, the blue whale  (Balaenoptera musculus) still likely trumps them all.

Tinysaurs

Mass Produced, Bioengineered Pets, implemented now! If you like your pets small and unusual, a great, highly amusing art work online that definitely qualifies as “edutainment”.  Sorry, it was the challenge of the day to use that word in a sentence, so I used it. I feel it’s an odious word!

Personally I like my pets unusual, but am not particular about size. Our household pet, a native carpet python may grow to three metres. She is nocturnal like us, easy to keep (except for the slightly elevated costs associated with heating), wonderfully placid and hypoallergenic as well. One of my many childhood fantasies was that it would be possible, even commonplace, to have small dinosaurs as pets by the time I was grown up. I still don’t consider myself as grown up, but I am disappointed that the moon is not yet a tourist destination, and that I can’t keep a Europasaurus holgeri at home or anywhere else. 

There’s no need to feel behind the times if you haven’t heard of this species, it was announced to the world through Nature in June (Vol 441 | 8 June 2006 | doi:10.1038/nature04633). The letter describes a dinosaur species that gradually became smaller over generations. Limited food supplies on an island in the Saxony basin (now Germany) made it a disadvantage to be big, with a requirement for lots of food. Hungry creatures breed less, so the smaller ones become the succesful breeders, the majority. 

Small is a relative term though. Europasaurus were a species of Sauropod, the largest animals to ever live. So these 'dwarf' adults had bodies of six metres in length according to the letter, and I suppose that means they might have weighed a tonne or so. Maybe a Europasaurus would not have made the ideal pet. Possibly an interesting riding animal.

Catching up on zoology news

Today's shopping excursion took me past the Brick Pits at Homebush Bay, home of the famous Green & Golden Bell Frog. Shopping for archery supplies, I was once again reminded of how much technology changes the daily substance of life. Previously, fletchings were rooster feathers hand made, then mass produced, cut and died into bright sports team suitable colours. Now the fletchings are plastic. Hard wearing yet flexible, gaudily rainbow plastic. I particularly like the day glo ones, and those that fluoresce under UV light. Picked up a few dozen to test a concept, and don't mind the thought of another drive out there once the design is set.

Individually fletchings were so cheap that I, from my cashless inner city world had to purchase a few extra to justify the use of the Eftpos machine. Probably a serendipitous embarassment though, as prototypes of any object have a habit of going badly awry on a bad day.

It got me to thinking though, that the underlying theory of archery had remained stable for a very long time. It's a science of materials as much as the physics of flight. A long time ago I worked in a team of experienced zoologists and botanists. Laboratory and field work were closely intertwined, hence theory and practice were also not divorced from each other. It's worth remembering that the 'old fashioned zoologists' whose stock in trade is painstaking observation have a lot to contribute to the most cutting edge research. Catching evolution in the act requires plenty of that, as much as it requires high throughput DNA analysis.