What Phylogenetics Tells Us About Scientific Incompleteness

Embracing Uncertainty in Science and in Life

Studying biology in University College London, the first major piece of coursework tasked to me is to write a 1500-word essay titled “What can phylogenetic trees tell us about how the complex eukaryotic cell evolved from prokaryotes?” While reading into the topic, it dawned on me that phylogenetics, a rather niche technique used in biology, not only allows us to understand biological systems, but reveals regions of ‘scientific voids’ in many areas of science.

An Essay About Phylogenetics

The old tree of life, taken from https://en.wikipedia.org/wiki/Tree_of_life_%28biology%29

For those understandably confused about the essay title, here is some simple context for this article. Prokaryotes are rather simple cells, being the first life forms that existed on Earth. Eukaryotes, however, are the Boeing 747s to the prokaryote’s paper airplanes. They have evolved from prokaryotes, becoming much more complex, with many features distinct from prokaryotes. By simply looking superficially at their features, one could not tell that they are related. However, if you look a little deeper, you would find certain sections of their DNA or certain proteins which are similar, which tells you how related the two groups of organisms are. This is the concept behind phylogenetics, which has become a useful tool in biology, particularly in evolutionary theory.

In reality, things unfortunately aren’t that simple. We have yet to find intermediates in the evolutionary process, as they were likely outcompeted to extinction. Hence, evolutionary biologists aim to figure out how prokaryotes changed so drastically to become eukaryotes by comparing the prokaryote most closely related to eukaryotes with the universal features all eukaryotes possess. However, because the two types of organisms being compared are so different, there is a plethora of possible mechanisms for this evolutionary process. Many have been proposed, but none really proven.

A diagram of the prokaryote-to-eukaryote transition. The last eukaryotic common ancestor (LECA) is a primitive eukaryote which possesses all universal features of eukaryotes.

If there are indeed no longer any extant evolutionary intermediates, does that mean that we will never truly know how the complex eukaryotic cell came to be?

The Scientific Void

A literal representation of the scientific void, taken from https://www.iflscience.com/a-giant-hole-in-the-universe-just-what-is-the-botes-void-64689

Seemingly unfillable scientific voids scatter sparsely in science. The origin of life, the origin of the universe and the evolution of eukaryotes are examples of it. Fascinatingly, it can also seen in the universal language of mathematics, which is aptly explained by a Youtube video made by Veritasium.

Veritasium’s video on mathematical incompleteness

In this video, Dr. Derek Muller talks about Gödel’s incompleteness theorems, which shows that it is impossible to establish a complete and consistent set of axioms for all of mathematics, leading to the fact that some true statements can never be proven to be true.

Given that philosophical axioms exists in science, there are bound to be certain theories and hypotheses in different scientific fields that can and will never be proven, creating the scientific voids described above. Yet, scientists keep persisting, without knowing whether the problem is solvable.

People often associate science with the principle of ‘knowing’ or ‘understanding’, which is what makes science consistent and reliable. For instance, by understanding Newtonian physics we were able to ideate and built reliable machines that benefit our everyday lives. On the other hand, science is actually derived from the scientific method, a process of ‘finding out’. Science thrives in the environment of the unknown, as that is where some of the greatest scientific discoveries are made. Science is accepting that we will never know everything, but still trying to find out and reaching greater heights by standing on the shoulder of giants.

Science and Religion

Science and religion comic, taken from https://www.churchtimes.co.uk/articles/2018/26-october/comment/opinion/there-is-one-thing-that-unites-science-and-faith

It is a common perspective that science and religion are greatly differing ideologies which directly oppose each other. They have commonly been pit against each other, with die-hard atheists and strongly religious devotees vehemently debating each other online, and in person. Atheists often use the argument that science relies on the observable truths of the universe, and hence holds greater credibility when compared to theological theories. However, keeping the incompleteness and inconsistencies of science in mind, this might not necessarily be true. In fact, science and religion neither prove each other wrong, nor prove themselves right. As cliché as it is, there is no wrong or right answers to the universe. Believe what you want, so long as you do not attack others for their beliefs or persistently push your beliefs onto others.

Having religious beliefs does have its benefits. Believing that there exists an all-intelligent being guiding you through life and into the afterlife brings a sense of assurance and stability, as well as purpose. That being acts as a consistent pillar of support which can always be relied on regardless of circumstance. On the other hand, believing in the axioms of science and the scientific method allows one to be comfortable in ignorance, by accepting the fact that we do not know everything, and will never know everything. Yet, we constantly ponder about these scientific voids as the beautiful mysteries of the unknown gives us strength to keep going.

I argue that religion and science differs not on the ‘what’, but on the guiding principles behind it. No one can truly definitely prove how the universe or life on earth came to be, hence arguing about these concepts is rather pointless. As an atheist, I take pride in appreciating the beauty of complexity and uncertainty. It is always so exciting to view reality from a scientific perspective.

“Religion is a culture of faith; science is a culture of doubt.”

— Richard Feynman

Closing Thoughts

Taking a step back and looking at uncertainty from a wider perspective, there are valuable lessons that we can takeaway from it. The first of which is the importance of having a sense of humility when perceiving the world around us. Even though we are the dominant species on this planet, we are still a servant to nature, and a mere tiny speck in the vast unknown universe around us. Secondly, the willingness to step out of our comfort zones and try our very best to figure things out is when we are best able to learn about both ourselves, and the things around us.

“Somewhere, something incredible is waiting to be known.”

— Sharon Begley

Harness you inner Elsa and keep diving into the unknown!



Critically analysing life a lot more than I should.

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store