The story goes that physicist Albert
Einstein lamented not having a solid enough mathematical grounding with which to
fully explain some of the ideas he was working on in later life. This Einstein anecdote
made such an impression on Prof Cang Hui that as a student he pursued mathematics
further, rather than physics, a subject he had excelled in since childhood. The
decision turned out to be a win for the field of biology and ecology. Hui has since
added much mathematical thought to environmental complexities such as climate
change, pollination dynamics and other chunks of Big Data with a biological or
To that more than 200 papers, two
books, eight chapters and 12 PhD students successfully supervised attest. In
2011 Hui received an Elsevier Young Scientist Award. Based on his h-index, the
B2-rated researcher counts among the top 10 researchers in mathematics in South
Hui joined Stellenbosch University (SU) in 2004 as a
postdoctoral researcher and is currently a core member of the Centre of
Excellence for Invasion Biology. Since 2014 he has been appointed as the South
African Research Chair in Mathematical and Theoretical Physical Biosciences in
the Department of Mathematics and is also affiliated to the African Institute
for Mathematical Sciences (AIMS, Muizenberg).
He is also the next speaker in the
Division of Research Development’s Forward with Research Impact lecture series
and will be talking about mathematical games between plants and their
mutualists on Wednesday 5 November at 13:00 at the SU Museum.
The Einstein moment
Hui, the youngest of two children, was
born in Xi'an in northwest China in 1977, the year in which the Chinese
Cultural Revolution ended. His parents were academically minded but because of
the political climate of the day did not have the opportunity to pursue
Hui, on the other hand, did. From an
early age, he was interested in how physics could help explain to him how the
world works. He became a member of the Chinese Physical Society at age twelve.
“I really enjoyed
physics, and the kind of questions it could answer. It was not only about how
it could be used to calculate things, but how it could also be used to explain things
using the equations,” he remembers.
He read about
Einstein’s lamentations while preparing for his matriculation test in 1994, at
a time when he was contemplating whether to further his studies in physics or
mathematics – both subjects that he excelled in.
more about the excerpt from the writings of another physicist, Arnold
Sommerfeld, at the time of Einstein’s 70th birthday, that so
influenced himi: “Einstein complained that if he could choose again, he’d have
chosen maths first, because his lack of knowledge in the field hindered him from
formulating certain things later in life better.
going to make the same mistake as Einstein: “I told myself that if I really
wanted to understand the physical world, I firstly had to prepare myself
He never did
go back to pure physics, but these days he counts quite a few physicists among his
network of collaborators in Europe, North America, China, Australia, and here
in South Africa.
himself as an applied mathematician by training who has the mindset of not only
wanting to formulate or compute things.
want to understand a system and what drives its dynamics,” he explains.
graduated with a degree in applied mathematics from Xi’an Jiaotong University
in 1997 and received an Excellent Undergraduate award. In his final year, he had
the good luck that his end-of-year project on epidemiological models with
time-variant differential equations was supervised by a renowned
biomathematician, Prof Zhien Ma. In the process, he became intrigued with the
idea of complex systems, and how these operate.
After completing his MSc in Applied
Mathematics in 2001 by modelling metapopulation dynamics in realistic
landscapes, Hui was awarded the title of Excellent Postgraduate at Lanzhou
University. His PhD in Mathematical Ecology followed at the same university in
2004, this time on the spatial and dynamic complexity found in metapopulations,
and how they persist.
During his PhD project, he joined the
China Eco-Economy Society to get first-hand experience of the field of biodiversity.
He took part in projects by the National Natural Science Foundation of China that took him to
river basins and alpine wetlands. His contribution to these projects
even saw him winning prizes from his local provincial government.
Studying the environmental side of bio-mathematics
wasn’t his first choice, however. During his first years of study, he very much
wanted to go into brain science because he viewed it as the “ultimate complex
system”. Luck was however not on his side, and as a second choice he started
looking at ecological systems and biodiversity.
With the benefit of hindsight, Hui now
says: “Today I think that ecological systems are even more complicated than our
brains. Our neural networks, once connected, cannot change much and become
nearly fixed by the age of seven. Ecological systems, on the other hand, can
have numerous numbers of species interacting with and co-adapting to each other
Hui thinks of complex systems in terms
of a game with multiple players all wearing the hats of the groups or species
they belong to. All are playing the game in such a way that it benefits themselves
without the mind of their group. The end results of each of these interactions
are quite difficult to keep track of, and to explain.
“Biology and the natural sciences are
about life itself. To try and understand it, you need more than just physical
explanations or physics. You have to ask how certain phenomena emerge through
complex systems. And that’s where maths come in,” he explains quite
His academic life of using and
creating new models therefore lies on the interface between mathematics and
biology. His interests have over the years broadened to proposing models and
theories by which to explain emerging patterns in whole-organism biology. When
fine-combing ecological data about a particular system or species, he is
constantly trying to find out the function and meaning of each species within in
a system, and how these influence the many other parts.
One of his
students is currently modelling the distribution of African dragonfly species,
to get a sense about their future movement in light of climate change. Another
is modelling the interactions of species within forests, as part of a major
larger international collaboration project. On the local front, he is about to
embark on a ten-year-long project looking at the interactions taking place on a
species level in a one hectare plot of fynbos in the Jonkershoek Nature
think mathematically to formulate a biological system, you first ask what is
happening. You also have to understand how, and only then you can ask why,”
explains the father of two pre-schoolers who likes seeing how they experience
the world as they grow up.
He reckons that in the era of Big Data
all research teams worth their salt should have a strong mathematical mind as
part of the team.
no longer the bottleneck when it comes to research. It is about how you are
going to use the data, and what you are going to focus on,” he explains. “We
need informatics to handle all the gigs of data being collected. We need
modellers and biomathematicians to work with it, and to improve our understanding
of a system.”