Michelle van der Bank’s Professorial Inauguration

Michelle van der Bank obtained her PhD in 1999 with specialisation in Botany. Currently, Michelle has an h = index of 26 (Google Scholar) and 22 (Scopus) with 86 peer reviewed, ISI accredited journal articles. Some of her papers have been published in high impact factors such as Nature, Proceedings of the National Academy of Sciences of the United States of America, PLoS Biology and Journal of Ecology.

To date, Michelle has successfully supervised 42 graduate students and has collaborated with a number of National and International colleagues.

In 2010, Michelle founded the African Centre for DNA Barcoding, the first DNA barcoding lab of its kind in Africa.

On Monday 5 March 2018, the Executive Dean of the Faculty of Science Professor Debra Meyer and the Registrar Professor Kinta Burger, hosted the professorial inauguration of Professor Michelle van der Bank, African Centre for DNA Barcoding (ACDB) at the Department of Botany and Plant Biotechnology at UJ. The topic of her address was “DNA barcoding at the ACDB: Current applications and future prospects”.

Inaugural Address

A summary of her inaugural address can be found below:

We developed two strong research programs at the African Centre for DNA Barcoding (ACDB) – molecular systematics e.g. large-scale phylogeny reconstruction based on molecular data, and DNA barcoding. We have used the core DNA barcodes to generate a barcode library for southern Africa (for systematic studies additional markers were sequenced). To date, more than 21,000 plant barcodes have been archived on the Barcode of Life Database (BOLD). Using this database, we at the ACDB have addressed questions related to community assembly, biogeography, phylogenetic diversification, and invasion biology. Taxonomic studies resulted in approximately 56% of all publications, but an important additional component (44%) of the output has addressed ecological and evolutionary questions, demonstrating the utility of barcode data beyond the fields of taxonomy and systematics.

Researchers at the ACDB used a barcode phylogeny of the trees of southern Africa to explore several ecological and evolutionary questions that have provided new insights into the history of the flora in the region. Some of our most significant contributions will be presented:

Plant community dynamics in response to large mammal disturbances

Here we used DNA barcode data to assemble the first complete phylogeny for all trees and shrubs of the Kruger National Park to explore the impact of large herbivores on plant community structure (Yessoufou et al. 2013). We showed that the exclusion of large herbivores results in impoverished plant species diversity. In addition, we revealed that plant community responses to herbivore exclusion depend on the initial structure of the community: communities that are initially phylogenetically over-dispersed tend to become under-dispersed after herbivore exclusion and communities that are initially under-dispersed tend to become over-dispersed after herbivore exclusion.

Phylogenetically informed biogeographical regionalisation

Here we used a time-calibrated phylogeny for southern Africa to shed light on evolutionary affinity of the biomes within it (Daru et al. 2016). This study showed that existing biogeographic divisions in the region represent discrete phylogenetic units – with the Fynbos biome being the most evolutionarily distinct. We were also able to identify two additional regions – the ‘Gariep Karoo’ and the ‘Zambezian transition zone’ – that were phylogenetically distinct, but which had been overlooked by more traditional species-level approaches.

DNA Barcoding and conservation of regional plant diversity

Here we explored the spatial distribution of different dimensions of tree diversity across southern Africa and evaluated the efficiency of hotspots in capturing complementary areas of species richness and phylogenetic diversity (Daru et al. 2015). We compared patterns of species richness, phylogenetic diversity, phylogenetic endemism, species endemism, ‘evolutionary distinctiveness and global endangerment’, and revealed spatial incongruence between these different facets of diversity. We found that no hotspot area was shared among all diversity metrics and that almost 70% of hotspot areas were unique to a single diversity metric (Daru et al. 2015).

Africa’s trees go underground in response to fire

Here we used barcode data to explore the phylogenetic placement of ‘geoxyles suffrutices’, so called ‘underground trees’, to examine the evolutionary drivers of this unusual life-form (Maurin et al. 2014). Phylogenetic analysis revealed multiple independent origins for this life-form and suggested that most geoxylic species arose in the Pliocene. Our analysis indicated that the geoxylic life-form most likely evolved in response to the effects of frequent fires where high precipitation occurs.

Invasive species in South Africa

We have generated and assembled an extensive DNA barcode library for non-native terrestrial and aquatic plants in South Africa. By placing non-native trees within our DNA barcode phylogeny, we were able to show that alien plants distantly related to native plants were more likely to become invasive, whereas alien plants closely related to native species were more likely to establish in the region without invading, a scenario that matches the Darwin Naturalisation hypothesis (Bezeng et al. 2015).

Trade in endangered species

Williamson et al. (2016) sampled 45 cycad specimens from the Faraday and Warwick traditional medicinal markets located in Johannesburg and Durban respectively. She used DNA barcoding to identify the species and found five Encephalartos spp. which are listed in CITES Appendix I as threatened or protected species in terms of the National Environmental Management: Biodiversity Act (NEM:BA) of 2004, being traded. Trade in such species is prohibited except for non-commercial purposes (e.g. scientific research).

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