Reef evolving fast enough say James Cook University Marine Biologists in Science, 4 June 2005.
Following a bleaching episode in 1998 involving half the coral on the Great Barrier Reef, probably due to abnormally warm water which caused the coral to die, scientists have feared global temperatures were rising so fast coral would be unable to evolve quickly enough to cope. The Science study shows that coral mix and match the algae they rely on to get energy from photosynthesis. Some were able to take up more heat tolerant algae (zooxanthellae), at a cost of much slower growth rates.
During bleaching, which can be triggered by a rise in normal water temperature of just 1 degree C, algae are rejected by corals. While it was thought most coral that survived bleaching replaced lost algae with others from the same strain, new research suggests they might be able to take up tougher strains in future. Zooxanthellae (algae) have much shorter generation times (than coral) and therefore much greater capacity to evolve and change if temperature rises, said Associate Professor Betty Willis. Dr Willis cautioned the work was preliminary.
The study has so far conclusively shown only that young coral start life with different types of plant partners. Whether mature coral really could mix and match plant partners to cope with heat stress was being tested. University of Qld Centre for Marine Studies Director, Ove Hoeghguldberg, said while the research was fascinating he doubted the phenomenon was going to be an easy escape route for coral. We should be seeing decreasing mortality by now if this was true, but over the last 20 years, which has seen the fastest rate of climate in 24 million years, it has got worse. Courier Mail Saturday June 5, 2004. p. 19.
Editorial Comment: This is yet another excellent illustration of everything being called evolution. No-one has observed the coral changing, and no-one has observed the algae changing. If the coral can incorporate already existing algae which differ from the ones they currently use, then neither the coral, nor the newly selected algae will be any evidence of any creature evolving.
Nor will it be any indication that the coral may not change back to choosing the other algal types when water temperature goes down. The most significant change observed is it has already been observed that changing to high temperature algae, slows the coral growth – but that’s not evolution either!
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