IS DARWIN’S TREE OF LIFE TRUTH OR A VISUAL TOOL FOR EVOLUTION?

Eva Wang (OHS) Since the first known living single celled organism to now, evolution has shaped our nature and our nurture. Every single organism has descended from the same unicellular prokaryotes that under natural conditions changed enough to ensure that 1.5 billion years later more complex life would start to take lead (eukaryotes). 500 million years later the eukaryotes divide out into three distinct branches which each start to evolve separately as the start of animal, plant and fungal life. Hence the growth of a tree had begun. Evolution isn’t a subject that can only be understood through complicated timelines and in depth breakdowns of each and every organism’s growth through natural selection. Having the visual diagram of a tree helps highlight the nature of evolution, which proceeds to introduce us to the start of topics such as genetics and inheritance. ‘As buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever-branching and beautiful ramifications.’ - Charles Darwin

By default, there is no denying that a tree is a very logical and straightforward tool to help visualise any idea related to links and direct relations between objects. Hence the same applies to evolution. Nonetheless, much of Darwin’s initial sketch looks more like a spider diagram than a tree. However the true concept and his later ideas connect each branch together, therefore bringing together the whole concept of there being a firm foundation, (or trunk) confirms that it can only be what he intended. In relation to what he clarified himself regarding the ‘tree of life’, his idea of vigorous ‘fresh buds’ essentially growing their own branches and forcibly pushing weaker ones aside clearly demonstrates the theory of natural selection. Survival. Yet how the earth is made up and filled with the ‘dead and broken branches’ indicates how without these deemed failures, stronger and newer ones would not have the foundation to grow, and like how roots need soil to anchor themselves deep into. Unfortunately, the idea of there being a tree of life where everything is related by evolutionary history is now seen as out dated. This is due to genetic tests showing that species used to cross breed much more than scientists (and evidently Darwin) originally believed. Therefore the branches between some organisms have been snapped and replaced by evolutionary pathways, resulting in a messier ‘web of life’. Despite it being displeasing, the ideology of there being a tree of evolution is no longer what is seen as the scientific truth (if it initially ever was seen as that due to the lack of evidence). However can the origin of evolutionary science still be seen as a tree? Yes, as even if branches get cut and ‘artificial’ pathways are built along it, the trunk and roots of the kick-start to evolution still inevitably remain.

Bibliography

David Penny, (2011), Darwin’s Theory of Descent with Modification, versus the Biblical Tree of Life [online], https://journals.plos. org/plosbiology/article?id=10.1371/journal. pbio.1001096#:~:text=The%20full%20quote%20 is%20%E2%80%9Cbuds,the%20surface%20with%20 its%20ever

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