science and creationism 15. botany © colin frayn, 2008-2011
TRANSCRIPT
Science and Creationism
15. Botany
© Colin Frayn, 2008-2011www.frayn.net
© Colin Frayn, 2008-2011www.frayn.net
Tree Ring Dating• “Dendrochronology”
– Trees (usually) grow one ring per year– Counting rings tells us a tree’s age– It can also tell us more…
• Climate affects a tree’s growth rate• Different growth rates lead to different ring sizes• So we can get a history of climate from tree rings
• Dating wooden artifacts– Of course, we don’t need to have a tree
• Wooden objects have tree rings in them• We can line up those rings with calibrated tree rings• Tells us when the tree was cut down to make the object
© Colin Frayn, 2008-2011www.frayn.net
Objections to Tree Rings• Dendrochronology is used to date old objects (>10,000 years)
– Wooden artifacts– Old (but long dead) trees
• Do trees reliably create 1 ring per year?– They sometimes create ‘double’ rings
• We can easily spot these and discount them• The species commonly used for dating do this very rarely
– Bristlecone pines: once in every few hundred trees– Ferguson, 1968, ‘Science’ vol 159
– They sometimes have ‘missing rings’• This would tend to make us underestimate the tree’s age
• Tree ring dating can be anchored– Wooden artifacts of known historicity– Evidence that correlates to known historical events
• E.g. unusually cold years after large volcanic eruptions• Can calibrate tree rings very accurately
© Colin Frayn, 2008-2011www.frayn.net
Anchored Histories• IntCal04
– The International Calibration for tree ring chronology
– Agrees on a rigorous set of samples– Anchors dates back to 24,000 B.C.– Calibrated by
• Other tree rings• Archaeology• Carbon-14 dating
Established scale
Matched sample
© Colin Frayn, 2008-2011www.frayn.net
Oldest Trees in the World• “Methuselah” (California, USA)
– Estimated germination 2832 BC• Germinated before the flood• How did it survive the water?
• Clonal species– Original trees reproduce by exact cloning– Dalarna, Sweden
• Norway spruce• Estimated age : 9,550 years
– Mount Read, Tasmania• Huon pine• Estimated age : 10,000 years
• Oldest living tree is <5,000 years old– This doesn’t imply that the Earth is young!
Img: Great Basin Bristlecone Pines
© Colin Frayn, 2008-2011www.frayn.net
Kei Mori and the Big Plants• Japanese physicist (1932-1990)
– Grew tomato plants in special conditions– No UV, IR light– Highly pressurised CO2
– Plants grew very quickly, provided high yield– Hypothesised that this might explain ‘giant’ biblical creatures
• I can’t find any research articles on this subject– How reliable is it?– The only reports I can find are creationist websites
• How plausible is the argument?– The vapour canopy idea is physically impossible
• See slides on the ‘flood’, ‘longevity’– Dinosaurs were not just ‘overgrown lizards’
• See slides on ‘dinosaurs & man’
© Colin Frayn, 2008-2011www.frayn.net
Genetically Modified Crops• Hovind claims that GM crops are evil
• Norman Borlaug (b. 1914)– Credited with saving over a billion lives…– …by developing genetically modified crops
• No evidence whatsoever that GM is dangerous
• GM crops can reduce our need for– Fertiliser & Pesticides
• Vastly reduce the ecological damage caused by adding harmful chemicals to the environment
• Breed disease resistant, high-yield crops– Farmland
• Vast areas of rainforest are being destroyed to provide farmland for arable crops
• GM crops would reduce this