New results continue to slay ecology zombies

Earlier this year, UNSW ecologists Angela Moles and Sichong Chen published field data from 25 locations across Australia which proved that plant seeds in far-north Queensland are no better defended from predators than those in Tasmania.

The results are the latest in a series, which Angela is using to slay some zombies – or at least some zombie ideas.

“Zombie ideas are theoretical ideas, which have been proven wrong by data, but that have been accepted for so long that people keep peddling them,” says Angela.

Angela’s first attack on zombie ideas came when she published the results of her “World Herbivory Project” in 2011, famously overturning the idea that interactions between plants and animals are stronger and more specialised in the tropics than at higher latitudes.

Her findings – the result of collaboration with 47 other scientists and studying 75 sites from the rainforest to the tundra over a period of two years – were contrary to the accepted wisdom that tropical plants develop stronger physical and chemical defences due to increased pressures from animal predators.

“In fact, we found plants do not suffer greater losses to herbivores in the tropics, and tropical plants are not better defended. In fact, plants tend to have higher levels of chemical defence at higher latitudes.” 

These findings also called into question whether these plant-animal interactions were the cause of the greater biodiversity observed in the tropics, and whether these ecosystems were actually the best place for pharmaceutical companies to look for new compounds for their drugs.

“These ideas had become widely accepted without being appropriately tested, because ecologists just didn’t have the resources for these big-data projects” says Angela.

As a growing body of work confirms her findings, international opinion is slowly but surely changing.

Another recent paper from Angela’s lab shows that plants experience more intense pre-dispersal seed predation at higher latitudes and that there is no latitudinal gradient in post-dispersal seed removal.  And in work with her students, she has even shown that birds, butterflies and flowers in the tropics are not more colourful than those in higher latitudes.

“What these results continue to make clear to us at that it is vitally important that ecologists (and scientists in other disciplines) search out and test any theories that have become accepted without appropriate empirical evidence.”

There are many more zombie ideas in ecology out there waiting to be slain.

Angela Moles is a Professor in the School of Biological, Earth and Environmental Sciences at UNSW Sydney. Her findings have regularly overturned traditional thinking and led to major advances in the development of understanding of global patterns in ecology. Angela is also well-known as an enthusiastic and effective science communicator. She has made substantial contributions to Australian ecology, through outreach, education, and service as the Ecological Society of Australia’s Vice-President for Student Affairs where she implemented two new national student prizes.

Angela has been awarded the 2018 Australian Ecology Research Award and will present the AERA Plenary at the Ecological Society of Australia Conference in Brisbane on Wednesday 28 November.

(Photo credit: Bearcage/Prime Minister's Prizes for Science)