My friend Paul made this totally awesome slide show video of the South Cluanie Ridge. It was a trip I had organised, but injury prevented me from going - enjoy
Sunday, 21 March 2010
Tuesday, 16 March 2010
Avalanches on Mars
This amazing photo shows a rock and ice avalanche on the surface of Mars. It is part of an image that captures 4 such events. The cliff is about 700 m high and the reflective white material is Carbon Dioxide frost.
More information and other great photos can be found here
Saturday, 20 February 2010
Open Questions
The more I think about it, the less the term supernatural makes any sense. So, can anyone give me a definition of it that does not require natural premises? Also, what makes it outside nature?
Monday, 18 January 2010
Monday, 4 January 2010
Tasmanian Devils And The Evolution Of a New Species Of Parasitic Tumour
Creationists love to misrepresent evolution and have an inordinate fondness for strawmen. These include:
1. Evolutionary change requires in increase in “genomic information”
2. Evolution only occurs within “kinds”
3. Speciation does not occur (incompatible with 2).
Number 1 would imply that genome size correlates with complexity. It does not. The largest known genome belongs to the single celled Amoeba dubia at about 600 billion base pairs. This is 200 times larger than our own genome. Even the lungfish Protopterus aethiopicus has a genome 50 times larger than ours. See here for phyletic comparisons .
This strawman also ignores the reality that some genes such as Abd-a can inhibit the development of complex structures such as abdominal appendages in invertebrates. Furthermore, subtle changes in regulatory sequences can affect morphological development that is controlled by genes already present. An example would be the expression of Bmp2 in the developing forelimb of bats .
One final problem for creationists is that natural or experimental deletions of parts (or the whole) of Alx-4 (loss of “information”) increases digit number in mammalian limbs – ie, less “information”, greater “complexity”.
Number 2 is just absurd as the spatio-temporal distribution of any number of transitional fossils shows. The creationist concept of “kind” is also confused.
Number 3. It happens! Deal with it creationists!
Now to the point, Jerry Coyne has posted this fascinating summary of work on tumours of Tasmanian Devils. It is significant because the tumours seem to have originated in an individual Tasmanian Devil and are now transferred from individual to individual by bite. Thus, making it a new species of parasite that is derived from the host species. It has obvious implications for all three points above. It is well worth a read.
1. Evolutionary change requires in increase in “genomic information”
2. Evolution only occurs within “kinds”
3. Speciation does not occur (incompatible with 2).
Number 1 would imply that genome size correlates with complexity. It does not. The largest known genome belongs to the single celled Amoeba dubia at about 600 billion base pairs. This is 200 times larger than our own genome. Even the lungfish Protopterus aethiopicus has a genome 50 times larger than ours. See here for phyletic comparisons .
This strawman also ignores the reality that some genes such as Abd-a can inhibit the development of complex structures such as abdominal appendages in invertebrates. Furthermore, subtle changes in regulatory sequences can affect morphological development that is controlled by genes already present. An example would be the expression of Bmp2 in the developing forelimb of bats .
One final problem for creationists is that natural or experimental deletions of parts (or the whole) of Alx-4 (loss of “information”) increases digit number in mammalian limbs – ie, less “information”, greater “complexity”.
Number 2 is just absurd as the spatio-temporal distribution of any number of transitional fossils shows. The creationist concept of “kind” is also confused.
Number 3. It happens! Deal with it creationists!
Now to the point, Jerry Coyne has posted this fascinating summary of work on tumours of Tasmanian Devils. It is significant because the tumours seem to have originated in an individual Tasmanian Devil and are now transferred from individual to individual by bite. Thus, making it a new species of parasite that is derived from the host species. It has obvious implications for all three points above. It is well worth a read.
Sunday, 3 January 2010
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