Life as we know it

Like the eusociality theory, the role of symbiosis in the evolution of life itself is still debateable and although we may never know the full extent of its role 1.5 billion years ago, scientists can make an educated guess (Aanen & Eggleton 2017). So far we’ve seen that symbiosis can drive the evolution of behaviours, structures, responses, new genes and new species as well as playing an important role in critical ecosystems and services such as coral reefs, seagrass meadows, pollination, primary production thanks to mycorrhiza and immunity.

 Some argue that symbiosis is so heavily integrated in individuals that we should study the evolutionary history and development of organisms with consideration of  the effects of their symbiotic microbiota, this new concept is called Ecological Evolutionary Development or Eco-Evo-Devo (Gilbert et al.2015). Another consideration is the possibility that symbiosis paved the way for major evolutionary changes, this idea is known as symbiogenesis. One example of a possible symbiogenesis is the possibility that plants moved onto land some 450 million years ago with the help of arbuscular mycorrhiza (Aanen & Eggleton 2017).

It is possible that symbiosis may have also been the driving factor for the evolution of complex life. This theory is referred to as Eukaryogenesis whereby scientists believe that eukaryotes may have formed through symbiosis, either by an endosymbiosis between two prokaryotes or by a symbiosis between a primitive form of a eukaryote and a prokaryote (Aanen & Eggleton 2017).

However, the exact role of symbiosis in evolution and the mechanisms that sustain symbiosis are not yet fully understood. Hence there are many conflicting ideas on just how influential symbiosis is on evolution and whether or not it should inflict a paradigm shift from current evolutionary principles (O’Malley 2015; Morran 2020; Aanen & Eggleton 2017). However, in light of what is known about symbiosis it is definitely something that should be considered during the conservation of current species and ecosystems (Carthey et al. 2019).

For more information on Eco-Evo-Devo go here: https://www.nature.com/articles/nrg3982

This is the final blog on this page.

Thanks so much for reading my blog and I hope you learned something new and interesting! 😊