Making Darwin's theory of evolution more accessible: A theoretical framework for designing effective evolutionary tree diagrams

Description

As visual icons of the process of evolution, tree diagrams need to be carefully drawn so that they accurately convey the process and help to clear misconceptions about evolution that the public may hold. Evolutionary trees illustrate clades, which are groups of organisms including an ancestor and all descendants of the ancestor. Other terms for these trees are phylogenies, phylogenetic trees, and cladograms. The trees “summarize the evolution of life: Darwin’s [1859] principle of the non-fixity of species, common descent, and diversification by a branching process from ancestral forms to modern ones” (Torrens & Barahona, 2012, p. 76).
As Moya (2014) notes, “[i]t is essential to understand evolution, because everything evolves … [Understanding evolution helps] us … to instruct society properly and provide citizens with criteria and the ability of critical judgment” (p. ix). For example, without knowledge of evolution, the public may not understand that viruses can change and therefore new vaccinations may be required to protect health. However, understanding evolution is not easy, and as will be discussed, misconceptions about it are due at least in part to the representation of time in the diagrams (Torrens & Barahona, 2012), which branches and is based upon generations rather than linear measurement. According to Machová (2021), who studied evolutionary trees in Czech biology textbooks, “many [trees] promote wrong understanding of both evolution and phylogenetics” (p. 29). This paper therefore aims to help science communicators create more accessible tree diagrams by offering a theoretical framework for designing them. The framework is founded upon the linguistic theory of time or tense and the linguistic metaphor “up is good”. The framework reveals that (1) western people conceive of time in language as flowing along the horizontal from left to right, so it may help to place evolutionary trees along the horizontal; (2) western people follow the metaphor that “up is good” so trees representing human evolution should avoid placing humans at the top of a tree or as the end result of evolution; (3) use of dotted instead of solid lines for branches as in Darwin’s original diagram may help to convey that an unknown number of generations, perhaps 1000s, may pass for a noteworthy change to occur; (4) use of a timescale may help with comprehending evolutionary time; and (5) text should accompany each tree to explain the process since graphics alone cannot explain the process.

Period	18 Jun 2024
Event title	Science Communication as a Human Right: International Communication Association (ICA) 2024 pre-conference
Event type	Other
Location	Brisbane, Australia, QueenslandShow on map
Degree of Recognition	International