The Best Australian Science Writing 2013 by Jane McCredie Page A

illicit drugs. While spiders on LSD and mescaline produced approximately normal webs, those on marijuana and the sleeping tablet chloral hydrate were unable to finish theirs. Spiders on speed worked very rapidly, but left large gaps in the structure.
    Perhaps part of the reason this experiment has found a place in popular culture has something to do with its widely quoted punchline. While the webs of spiders on most of the drugs retained a semblance of normal structure, one drug produced webs so asymmetrical and eccentric that they would barely have been functional. That drug was caffeine.
    Just as phytoestrogens are not produced for human benefit, so plants do not generously produce caffeine to help sophisticated urban dwellers kickstart their mornings. Caffeine is believed tohave evolved as a natural pesticide. And while it is effectively metabolised by the human body, and therefore not peed out like other drugs, some caffeine does find its way into waterways, possibly through being tipped down the sink, or when cups are washed.
    What would the South African clawed frogs make of all this? Modern medicine has come a long way. The frogs have retired from their busy lives of international travel and being injected with human piss. Perhaps now they can sit back and relax with their girlfriends – of which they will have many more now that endocrine disrupters have feminised the species – and enjoy swimming in waterways that human beings have thoughtfully laced with a sophisticated coffee-pharmaceutical blend.

    Aquatic lifestyles
    Going, going, gone

Dreamtime cave
    Elizabeth Finkel
    A small Aboriginal woman peers through the microscope at the sliver of rock. Perched precariously on a stool, her feet barely touch the ground. ‘Do you want us to go on, Auntie?’ asks archaeologist Bruno David. ‘Yes,’ she says emphatically in a low quiet voice. ‘I want my grandchildren to know about our culture.’
    It’s an unusual gathering for the archaeology lab at Melbourne’s Monash University. ‘Auntie’ is Margaret Katherine, an elder of the Jawoyn people; David is the lab’s co-director. Then there is carbon-dating expert Fiona Petchey from New Zealand’s University of Waikato, archaeologist Mark Eccleston – with his shiny steel X-ray fluorescence gun – from Aboriginal Affairs Victoria, plus documentary film-makers Bentley Dean and Martin Butler, and me.
    We are all focused on Margaret Katherine, whose attention is on a triangular piece of quartzite measuring close to 4 centimetres across its greatest length. Under the microscope its treasure becomes clear: a very finely painted black cross whose lines seem to continue beyond the edges, as if it were part of a larger image. The black pigment is charcoal, meaning it might be possible to scrape off a tiny bit to carbon-date the miniature painting. This is an extraordinary artefact, recovered by David’s colleague BryceBarker from the University of Southern Queensland during a recent dig of the floor of Gabarnmung cave.
    Gabarnmung has been rewriting world pre-history since its 2006 ‘rediscovery’ by the Jawoyn. The cave is perched on a sandstone escarpment high in southwestern Arnhem Land, east of Darwin. Arnhem Land is wholly owned by Aboriginal tribes and much of the escarpment lies within the 50 000 square kilometres ancestral lands of the 600-member-strong Jawoyn. The escarpment’s unusually hard quartzite rock is the canvas for one of the world’s most spectacular collections of rock art – an archaeologist’s utopia, its diverse styles preserve a sequential record of a people who have occupied this landscape for more than 50 000 years.
    Much remains to be learned about this art. Archaeologists are uncertain about the age of the paintings and their precise meanings. It’s safe to say some tell stories of the Dreamtime – the Aboriginal telling of the creation of the world –