The Tree of Life is a powerfully attractive representation of an evolutionary process and pattern that has been severely challenged by the discovery of extensive horizontal gene transfer in bacteria, archaea and other organisms.
To mark the 150 years since the publication of Darwin’s On the Origin of Species, a new thematic series, ‘Beyond the Tree of Life’, has been published in Biology Direct. The articles in this series reflect on the future of Tree of Life studies in light of the challenges they face and the stimulus such challenges have offered to efforts to reconstruct a unique tree of evolutionary relationships.
Introducing the series, Koonin and O’Malley examine the original Tree of Life hypothesis and heuristic in light of recent discoveries. The series currently features insights into the prokaryote-eukaryote divide (Lane), the challenges faced with generating and interpreting a tree or network of all genomes (Beiko), and a review of three major transitions in early evolution when considered without a Tree of Life (Martin).
In a thought-provoking opinion piece, Kutschera also presents a novel perspective on macroevolution in proposing a tree-like "symbiogenesis, natural selection, and dynamic Earth (synade)-model".
Irrespective of whether these new approaches modify or reject the traditional Tree of Life model, the articles in the series illustrate the “wealth of insight gained by thinking beyond a central icon of evolutionary biology”, O’Malley states.
This series has been published as part of the ‘Questioning the Tree of Life’ project supported by the Leverhulme Trust. This was one of a number of exciting projects coinciding with Darwin year in 2009. Other projects included the Wellcome Trust’s ‘Interactive’ Tree of Life allowing you to visualize the evolutionary links between living things on earth.
Further articles will be added to the series soon; to be notified when they are published, please sign up for article alerts.
(Image courtesy of Mandy Budan)