By Lynley Hargreaves 12/05/2016

The journal of the Royal Society of New Zealand began its life in the 1860s covering a wide range of topics. New editor Professor Ewan Fordyce FRSNZ would like to regain a little more of that breadth of discipline. The University of Otago Professor knows something about crossing disciplinary boundaries, as a paleontologist in a Geology Department, working on fossils that are represented by living animals.

Are you hoping to make the journal more interdisciplinary?

Professor Ewan Fordyce
Professor Ewan Fordyce FRSNZ

For any local journal that overlaps with other local journals, we have to think carefully about who it appeals to – in a way that’s a challenge for all of our journals in New Zealand. Perhaps we could do more to pitch the journal at the Fellows of the Royal Society of New Zealand. They represent a range of disciplines and if we can broaden the articles published to attract more readership amongst that group that would be a good thing. Even within the sciences I wonder if there is more that we could do to reach out to the subjects that tend to be more interdisciplinary, like oceanography.

Although you work on fossils, you’re involved with looking at stranded whales too?

Yes, my interest is in understanding how whales and dolphins work. I’m driven by wanting to understand the history of the group, and to use insights from modern biology to help bring a fossil to life. In the past people might kill a whale or a dolphin to understand its workings, but investigating natural deaths gives an opportunity for us to expand our knowledge of the species.

How old are the fossils you work on?

Most of the fossil whales from New Zealand are about 25-30 million years old. This was a time of great submergence in New Zealand – some people would say that all of New Zealand was submerged and others say it was a string of little islands. These New Zealand fossils have made quite an impact on our wider understanding of cetacean history, because they date from around the start of two great lineages: baleen whales and toothed whales and dolphins.

What are the big questions in whale and dolphin history?

One big question is – why are some groups represented by so many species, and some by so few? Globally, there are almost 40 species in one family, the ocean dolphins – such as Hector’s dolphins, pilot whales and many more. But for the Amazon river dolphin, it’s the only species in its family.

Some groups were represented by many more species in the past than today, and it’s possible that a drop in diversity of species is the result of competition between groups. But there’s also a lot of interest in the physical drivers of evolution and extinction, such as climate change. We know that oceanic and continental change – driven by plate tectonics – can dramatically alter the area of habitats for dolphin or whale species. For example, if sea level drops at a time of glaciation, that leads to dramatically less shallow area habitat for whales and dolphins. Would this cause evolution or extinction?

And how can biological drivers affect whale and dolphin species?

There is an interesting hypothesis that some toothed whales and dolphins have adapted to killer whales as their main predators by using sounds that orca might not hear well. It has been suggested that the big modern whales migrate into tropical waters to have their young because killer whales are not very common in those waters.

Another example involves the big continental areas, in which some river systems have fresh water dolphins. These dolphins look rather similar to each other. There are examples in the Amazon and until recently in the Yangtze River in China. For a long time it was thought that these dolphins were closely related. But now their structures have been looked at closely, along with genetic profiles, and we can see that those groups actually represent quite different lineages. All of them came from marine ancestors and separately evolved similar habits and lifestyles in different large river systems.

These interviews are supported by the Royal Society of New Zealand, which promotes, invests in and celebrates excellence in people and ideas, for the benefit of all New Zealanders.