HKU Bulletin February 2004 (Vol. 5 No. 2)

29 W hen Peter Lucas developed his groundbreaking theory of why our primate cousins developed colour vision he had no idea of what he was letting himself in for. The anatomist spent five nerve wracking months in war-torn Uganda painstakingly piecing together evidence that not fruit but leaves have been the key evolutionary factor. Lucas said: “I spent five months in Kibale. It became quite dangerous with remnants of Idi Amin’s army, Muslim separatists from the north and various other units. “The mountains were nearby and on the border between Congo and Uganda where this rag-tag army were coming down to do raids. “I had just come down to Kibale and a few people were killed and then this army became trapped by the Ugandan army. It was pretty frightening at times.” A Reader in the Department of Anatomy, Lucas had long been interested in the evolution of man but in 1998 began to focus on the development of colour vision. Humans are rare among mammals in having trichromatic vision, which revolves around a two colour axis: red-green and yellow-blue – which intersect at right angles. All colours we see are a variation on this axis. Early mammals had poor colour vision because they were largely nocturnal animals but 90 million years ago the order of primates – including humans – developed. As humans evolved they developed red-green vision, in addition to the yellow-blue axis they inherited. Not all monkeys, however, have been so lucky. While all old world monkeys (OWM) also got red-green vision most new world monkeys (NWM) did not. The questions is why? Conventionally scientists thought this was to do with monkeys being able to discriminate between ripe and unripe fruit. When it was discovered that one species of NWM had developed trichromatic vision completely separately from OWM, however, Lucas was intrigued. He said: “Fruits are not always available so what are you going to eat when they are not around? Leaves are the critical resource that monkeys need to survive when fruit are not around.” “In tropics 50 per cent of young leaves are red. My view was that they developed colour vision to find edible leaves.” It was only when Nature magazine published a paper in 2001 that Lucas’s theory began to get the notice of the wider scientific community. But last year (2003) has seen the full fruits of Lucas’s global research published in Evolution magazine. What his research team witnessed was evolution in action. Do Primates See Red? They found that while some primates possessed routine trichromatic vision – colour vision as standard – others saw variations within the same species. Some would be dichromatic – blind to red-green – while others were trichromatic. Lucas said: “Primates are very complex and there are still evolutionary changes taking place. “For example the distribution of red-green colour blindness seem to have a geographic factor because it becomes more prevalent the further you are from the equator.” For the time being Lucas has put a stop to the research but he believes his theories will stand the tests of time. He said: “This is ext remel y impor tant in terms of understanding abilities and senses and I think that it shows there is a place for intuitive research in these days of what I consider to be often formulaic research.” 28 RESEARCH AND TEACHING Teaching Fellowship Awards D r Henry Lau, Associate Professor, Department of Industrial and Manufacturing Systems Engineering, said: “I really try to put student-centred learning into action: What the student feels is the most impor tant aspect of capturing knowledge. In particular, as an engineer they need practical exposure and practical case studies to appreciate the abstract knowledge we deliv “ e T r. here are lots of ‘hands on’ projects, competitions, firm visits and on-site surveys. I ask them to bui ld models prototypes and enter competitions to both apply and appreciate what they have learnt. I also use new technology to deliver courses through on-line web-based e-learning systems. Students can, for example, go into a virtual environment inside the company. Different modes of learning help to capture knowledge. “I am pleased to have the recognition of the years of effort spent on this and also feel it vindicates the importance of experience sharing because I do not come from an academic background but a work one.” Student Albert Ko, from his department, said: “I have known him for two years since I first joined HKU. I think he has a very good very strong academic background and is a willing teacher who is prepared to spend time with students to a level that most supervisors are not prepared to do. “There are lots of times when students look for supervisors only to find that they are often too busy with administrative duties. But Lau spends lot of time with students. “I think he is a mentor who creates team spirit among research students. Abroad research students work together towards common goal and this is quite uncommon in Hong Kong. “Lau, however, creates this kind of cooperative environment.”