Final answer:
The data supports the overkill hypothesis, suggesting that human activity contributed to the extinction of large herbivores in Australia.
Step-by-step explanation:
The data suggests that the extinction of large herbivores in Australia is more likely to be caused by human activity rather than climate change. The study found that the decline in sporormielle spore abundance, which correlated with the disappearance of large herbivores, occurred around the time when the first humans appeared in Australia. This supports the overkill hypothesis, which suggests that human hunting contributed to the extinction of these large herbivores.