Research by the Australian Institute of Marine Science and James Cook
University into coral hybridisation offers new hope for the ability of
the Great Barrier Reef and other reefs around the world to adapt to a
changing environment.
AIMS geneticist Dr Madeleine van Oppen has discovered that the
abundant Acropora genera of corals can cross-breed and does so in
nature.
Acropora is considered one of the most important corals in the
Pacific and Indian Oceans and in the Caribbean Sea because it is one of
the most plentiful, at 180 species rich.
The latest research results challenge the long-held belief that
hybridisation is only significant in the evolution of plants and not
animals. But it is taking some time to convince the science community of
Dr van Oppen's findings.
At this stage Dr van Oppen said it was not clear whether the newly
discovered evolutionary patterns were restricted to Acropora or
could be generalised to other groups.
"We have found one other coral genus, Montipora, also
shows patterns of evolution similar to those in Acropora,
suggesting that hybridisation occurs in this coral genus as well,"
she said.
The biggest reproductive event in the animal kingdom, the mass coral
spawning discovered in the mid 1980s, unlocked the key to the
proliferation of the reef.
Now this research sheds light on the evolution of the reef’s
biodiversity and its likely evolution into the future.
"We believe hybridisation has contributed to the enormous
success of Acropora," she said.
"The high level of genetic diversity provides an evolutionary
advantage to this group of corals because the more genetic diversity
there is within a population or species the more likely it is to be able
to respond to environmental changes," said Dr van Oppen.
"I’m not saying it can survive rising sea temperatures, it is
too early to say. However it does create an enormous capacity for
adaptive evolution."
The research is a collaborative effort between AIMS and James Cook
University biologist Associate Professor Dr Bette Willis, and Dr David
Miller, a Reader in the Comparative Genomics Centre.
For the past six years, the team has set up base camp on Magnetic
Island during the spawning phase in a bid to collect eggs and sperm for
cross-fertilisation experiments.
Dr van Oppen said it was important to understand the role
hybridisation played in shaping the reef from the beginning, to manage
it in the longer term.
