[Time Trowel] Evolution and the sneakiness of COVID

A trowel (/ˈtraʊ.əl/), in the hands of an archaeologist, is like a trusty sidekick – a tiny, yet mighty, instrument that uncovers ancient secrets, one well-placed scoop at a time. It’s the Sherlock Holmes of the excavation site, revealing clues about the past with every delicate swipe.

Last month, I wrote about human evolution and the increasing importance of island Southeast Asia in the diversity of the genus homo. As a prime example of evolutionary development, the emergence of new species, called speciation, is governed by the four forces of evolution: mutation, gene flow, genetic drift, and natural selection. But here’s the twist: our understanding of evolution itself is a bit like fashion trends in science — constantly evolving as new collections (or in this case, datasets) strut onto the scene, challenging last season’s haute couture models. This fluid nature of science means that our models adapt and change, sometimes as dramatically as bell-bottoms giving way to skinny jeans.

Enter the dynamic duo of natural selection and inheritance. For a while, Charles Darwin and Alfred Russel Wallace were like designers unveiling a groundbreaking fashion line without quite knowing what fabric it was made of. They proposed natural selection, but the material — how traits were inherited — was missing. Cue Gregor Mendel, the unsung hero working quietly on pea plants, who unknowingly provided the missing swatch of fabric with his work on inheritance. Suddenly, the model of evolution was complete, integrating Mendel’s work on genetic inheritance as its crucial component. 

This evolution of evolutionary theory showcases how science is more akin to a lively debate club than a static library of universal truths. Our current understanding, enriched by genetics, stands on the shoulders of giants — Mendel’s peas included — highlighting mutation, gene flow, genetic drift, and natural selection as the core forces fashioning the diversity of life.

Mutation is one of the mechanisms or factors through which random changes in DNA happen, leading to novel genetic material among a population. Gene flow describes the import and export of genetic materials that take place when individual members from one population interbreed with those from another population. Genetic drift arises when a change in the proportion of a gene variant (allele) in populations occurs by chance as a result of sampling organisms. Natural selection ensures that individuals with advantageous heritable traits are more likely to survive and reproduce.

When applying these four forces, the dynamic interchange between them can be seen for people of COVID-19. This is mutation in action since the virus frequently mutates and thereby is always throwing out new variants (from Alpha to Omicron). As people move across populations in the world and interact, the virus will be passed across populations (gene flow). An outbreak of strains of the virus can similarly sweep through populations only because they are favored by the vagaries of chance as they show genetic drift. Natural selection is observed in how some variant becomes more dominant because they’re more transmissible or able to evade immune responses at best and thus having a better chance of surviving and spreading.

This evolutionary viewpoint allows us to understand the complex ways through which COVID-19 mutates and it spreads, with the emphasis of the need for global cooperation and alertness and that the need for them is to monitor and react to these mutations. These further underscores the manner in which human behavior and biology are intermeshed with the virus’s evolutionary machinations towards the direction of the course of the pandemic.

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, offers a clear example of evolution in action. Initially identified in late 2019, this virus rapidly spread across the globe, leading to significant mortality rates. However, as the pandemic progressed, we witnessed an evolutionary shift in the virus, moving from high mortality (leading to many deaths) to high morbidity (causing more infections but fewer deaths).

This shift can be understood through the lens of evolutionary theory. Viruses, like all organisms, are subject to the principles of natural selection. Those that can spread more effectively have a greater chance of surviving and reproducing. In the case of COVID-19, the initial strains were highly lethal, which limited their ability to spread. A virus cannot reproduce if it quickly kills its host or leads to stringent quarantine measures.

As mutations occurred some strains developed that were less deadly but more contagious. These types could infect more people because those infected were less likely to be severely ill and more likely to interact with others, unwittingly spreading the virus. This is an example of the virus evolving to maximize its transmission.

The evolution of COVID-19 demonstrates how pathogens can adapt to their environments. While a highly lethal virus might cause a short, intense outbreak, a less deadly but more transmissible virus can lead to widespread, persistent infections. This evolutionary trajectory highlights the importance of public health measures and vaccination campaigns in controlling the spread of such viruses, as they continue to adapt and evolve over time.

Viruses, like our dear COVID-19, are all about survival of the fittest. And guess what? Being super deadly isn’t the smartest long-term strategy. Why? Well, if a virus knocks out its hosts too quickly, it runs out of places to crash. It’s like throwing a wild party and accidentally making all your guests leave early.

So, what did COVID-19 do? It morphed, like any self-respecting villain in a sci-fi movie. The newer versions of this virus started playing the long game. They became less like a horror movie monster and more like that annoying friend who crashes on your couch and never leaves. These versions were less deadly but more contagious – think more sniffles, less doom and gloom.

This is evolution in action: the virus evolves not through conscious effort but through natural selection favoring traits that enhance its transmission. It’s like COVID-19 realized that if it wants to stick around in the party of life, it had better not knock out the guests.

Anthropologically speaking, this shows us that just like humans, viruses adapt to their environment. For a virus, a good environment is one where it can jump from person to person easily. So, the newer versions of COVID-19 are less like a raging bull in a china shop, and more like a sneaky cat burglar, slipping in unnoticed but everywhere.

For us, this means we have to stay on our toes. Vaccines and health measures are our way of upgrading our defenses, like leveling up our own characters to keep pace with the evolving virus. Vaccines work, so please get them. Even though viruses and bacteria might evolve since it’s a dynamic back-and-forth, a real-time strategy game where both sides are constantly adapting. And understanding this helps us see why it’s so crucial to keep modifying our strategies, like updating vaccines and staying vigilant with our health behaviors.

So, there you have it: COVID-19’s evolution is a story of adaptation and survival, a natural phenomenon that’s as old as life itself, only this time, it’s happening fast-forward, right before our eyes. – Rappler.com

Stephen Acabado is professor of anthropology at the University of California-Los Angeles. He directs the Ifugao and Bicol Archaeological Projects, research programs that engage community stakeholders. He grew up in Tinambac, Camarines Sur. Follow him on IG @s.b.acabado.