Evolutionary biologist Jeremy Austin.
Credit: Jeremy Austin
Most people enjoy looking at extinct animal exhibitions at museums, but not like evolutionary biologist Jeremy Austin. For him, these animals are invaluable packages of ancient DNA that can help us understand the evolution of ancient animals and how to conserve existing species.
Whilst in his third year studying a zoology and botany degree at the University of Tasmania in Hobart, Austin was offered a rare opportunity to conduct research in Antarctica. The research involved collecting the DNA remains of krill (excreted from penguins) to investigate a living bacteria.
"This got me doing some molecular biology work, which got me interested in using DNA to understand evolution," said Austin. Fortunately, the field of studying 'ancient DNA' was being born at the same time, and ever since, Austin has been combining the studies of ancient DNA and molecular biology to answer big questions about evolution.
In 2010, Austin worked on a project investigating the haemoglobin extracted from the blood of ancient woolly mammoth bones. Using this ancient DNA, Austin and his team at the University of Adelaide in South Australia sequenced the woolly mammoth haemoglobin genes in order to understand how this prehistoric pachyderm survived the frigid temperatures of the Ice Age. Haemoglobin in the blood carries much needed oxygen from the lungs to tissues in the rest of the body.
Using Polymerisation Chain Reaction (known as PCR - a method of amplifying small sections of DNA for analysis) to sequence the gene, collaborators in the U.S. were able to analyse how the mammoth haemoglobin worked in different temperatures. They found that it could operate at much lower temperature compared to that of humans and other animals living in more temperate climates. "This helped answer the question about how the mammoth were able to survive in cold climates without the tips of their trunks, toes and tails freezing. The haemoglobin had a special adaptation to allow this," said Austin.
While the jury is still out on why mammoths went extinct, DNA evidence suggests that the mammoth population remained stable in size right up until the time they became extinct some time in the last 10,000 years. Austin believes that further DNA research might be able to distinguish between whether the cause was humans or climate change or a combination of the two.
When he is not 'resurrecting' mammoths, Austin uses his talents in DNA analysis to help the fast declining modern endangered species such as the Tasmanian Devil (Sarcophilus harrisii), which has been plagued with a deadly facial tumour disease. "We have used DNA to show that the Tasmanian Devils have a low genetic diversity, which explains why the devils are faced with the tumour disease and how it has been so easily spread amongst the species."
Using ancient DNA to understand the impacts of climate change and environmental change on populations over time, has been very rewarding for Austin. "My job has allowed me to travel to all sorts of weird and wonderful parts of the world," he said, adding that his job can sometimes be similar to that of an explorer. "You can be the first person in the world to discover something or work on a group of animals or species, which is pretty exciting."
