Volume 36 Number 1 December 2009 is passed on only through the male line. The only source of variation among mtDNA types is mutation, and the number of mutations separating two mtDNA types is a direct measure of the length of time since they shared a common ancestor. Since women do not carry Y-chromosomes, they can only be tested for mtDNA, but men can be tested for both types. Occasionally some of the genes carried by the DNA types mutate and the resultant genetic changes are passed on to future generations. The mapping of these mutations allows geneticists to track the history of various population groups. This has enabled researchers to determine that the most recent common ancestor of all modern humans on the maternal side Reports covering the period February to June 2009 lived some 150 000 years ago, while that on the paternal side dates to somewhere between 60 000 and 80 000 years ago. Prof. Soodyall then provided information on three facets of her work. The first is of a scientific nature and involves mapping the genetic codes of populations around the globe, but in particular in sub-Saharan Africa and the Indian Ocean islands, and especially those groups that have lived in relative isolation in a particular region over a long period of time. The second aspect of her studies revolves around three burning questions: 1. Is it possible to localise the most likely regions for the origins of various lineages? EVENING LECTURES 2. What impact did trade, which had occurred for well over 2 000 years in the Indian Ocean, have on population groups? 3. If the African continent is divided by region and language, do the results mesh with the genetic data? February: DNA is at the heart of evolution She explained that her work covered population genetic studies in coordination with a world- wide study undertaken by the National Geographic Society. She related how the knowledge Professor Himla Soodyall is Director of the Human Genomic Diversity and Disease gained through DNA studies had been used to demonstrate that Homo sapiens sapiens evolved in Research Unit, National Health Laboratory Service, SA Medical Research Council. Africa and then about 60 000 years ago began migrating to the rest of the world. She pointed out he day of the lecture, 12 February 2009, was the 200th anniversary of the birth of Charles that excavations at early human sites, such as Border Cave, could provide supporting evidence to Darwin. Prof. Himla Soodyall introduced her lecture by saying that this date was being demonstrate that this migration had started from southern Africa. In this respect it is important to celebrated worldwide as it marked the enormous contribution that human curiosity and note that the oldest branches of Y-chromosome DNA are found in San populations in southern T th ingenuity had made to scientific knowledge. The year would also be the 150 anniversary of the Africa, although also in population groups in the Sudan and Ethiopia. publication of Darwin’s On the Origin of Species in 1859. For more than 20 years Darwin had She elaborated on some other research projects, including research concerning the origin of collected vast quantities of scientific data and pondered the issue of how animals and plants the Karretjie people living near Colesberg. Their ancestry had been unclear since they were changed their morphology over long periods. Eventually he realised that the mechanism under- nomadic sheep shearers and fence menders. Samples taken from 36 individuals had demonstrated lying the process of evolution was that of natural selection. This idea led to him to publishing On that their lineage can be traced back to an origin that is common in Khoisan populations and is the Origin of Species. Darwin’s work provided the foundation for the now convincing evidence confined to southern Africa. that modern-day genetic studies have unravelled concerning human origins. Mitochondrial DNA Another of her projects had examined the population of Buysdorp, a small town situated north (mtDNA) and Y-chromosome DNA data have provided insights into how females and males, of Makhado (Louis Trichardt), which was founded by the son of the renegade Coenraad de Buys respectively, have contributed to shaping our evolutionary history. In addition, data from the from whom the inhabitants are reputedly considered to have descended. If this were indeed the completed human genome sequencing project, coupled with genome comparisons, have provided case, the men would all carry the same Y-chromosome, yet tests showed that it occurred in only deeper insights into what makes us human. Through time, species adapted to the environment, but eight of the eleven men tested. you could not change your DNA, your blueprint of life. Prof. Soodyall also referred to her research project related to the ancestry of people living in Prof. Soodyall’s research focuses on the evolutionary history of the peoples of Africa and she is currently the principal investigator representing sub-Saharan African on the Genographic A publication of the Trans-Vaal Branch Project, which is supported by the National Geographic Society in partnership with IBM and the South African Archaeological Society Waitt Family Foundation. In her lecture, Prof. Soodyall introduced the principles of genetic research and elucidated the mechanisms underlying the formation and evolution of human traits. PO Box 41050 Craighall 2024 She elaborated on the two types of DNA that were used to trace ancestry: mtDNA, which lies Editor: Reinoud Boers outside the cell nucleus and is inherited from the maternal side, and Y-chromosome DNA, which Production: Marion Boers the Maldives. This string of islands had been occupied for over 2 000 years and had been a Anniversary of an extraordinary innovation, Charles Darwin’s 1859 book On the Origin of stopping point for Indian Ocean traffic over a long period of time. The ancestry of the original Species. About the book, the philosopher, Daniel Dennett had said, ‘If I were to give an award for inhabitants was not clear, yet many inhabitants displayed physical traits reminiscent of southern the single best idea anyone has ever had, I’d give it to Darwin.’ Darwin was intrigued by the Indians and their language was related to Dravidian. Results from mtDNA tests showed that 58 wonderful diversity of species each with its own abilities to survive in a changing world, and the per cent belong to the M-Haplotype, which is common in southern India and Sri Lanka, 25 per most important idea he had given us was that we are all connected to and had grown out of the cent to the U-Haplotype, which is common in Eurasia, and 2,7 per cent to the D-Haplotype, which great family tree of life. He wrote: ‘I should infer from analogy that probably all the organic is common in East Asia. Y-chromosome tests revealed that over 50 per cent of men belonged to beings which have ever lived on this earth have descended from one primordial form, into which the Indian Haplotype, while 20 per cent were part of the J-Haplotype prevalent in the Middle East. life was first breathed’. Himla Soodyall acknowledged the significant role of fellow researchers in the Human Recognising our interconnectedness to this family tree, according to Croucamp, can be a Genome Project, for example James Watson and Craig Venter, referring to an article published in source of profound inspiration. We are not parachuted into the universe; we are grown out of it. Science and Nature in 2003. She mentioned significant biology informatics initiatives such as the We now know that we carry memories of the last 14 billion years in our bodies. An example is the research of Francis Collins and the important research being done at Wonderwerk Cave and carbon we carry in our bodies. Carbon is the most important ingredient of organic molecules. It Pinnacle Point. She also referred to the Genographic Project, a five-year genetic anthropology was created inside stars in the early universe. We are literally made out of stardust. The more study that aims to map historical human patterns, and to research that has a close bearing on cynical amongst us might say that we are made out of the nuclear waste of burnt out stars. contemporary societies. This included research on cultural and physical changes that followed the We carry memories of that moment when single-celled organisms joined together to become domestication of cattle some 7 700 years ago, the development of lactose intolerance and lactose multi-cellular organisms. This was the moment that fatty acids, those healthy Omega-3 oils one persistence. She also touched on adaptations related to carbohydrate and alcohol metabolism, and can buy in health shops, first appeared in the sea and combined with cell membranes to create to projects that focus on the split of the south-eastern and southern Bantu-speaking peoples. Prof. semi-permeable membranes making inter-cellular communication possible for the first time. We Soodyall highlighted the HapMap project collaboration that identifies single-nucleotide even call parts of our brain reptilian because we share it in common with reptiles. We call other polymorf (SNP) base changes and that has collected 3,1 million SNPs over three years, and the parts of our brain mammalian because we share it in common with mammals. There is even a development of a map of recent positive selection in the human genome, such as for example the bone in our ear that used to be the jaw of a fish. If fishy bits in our ear is a strange thought, consider selection of genes for skin colour.