Death makes us alive
- Delia du Toit
Without death, there would be no life – this might sound like ancient mysticism, but Wits scientists are proving it.
Why do we die? You’ve asked this before. We all have. It is a question that has plagued humankind since the birth of our species – and an issue that few people would even consider tackling.
“This is one of life’s most fundamental questions,” says Professor Pierre Durand?of the Evolutionary Studies Institute at Wits. “Why do we have to die? Is it inevitable? What would happen if we were immortal?”
Durand and his team are trying to connect these philosophical questions with empirical biological evidence, in an attempt to contribute to the field of naturalised metaphysics, a philosophical worldview which holds that?nature?is in fact all that exists.
Durand’s book, The Evolutionary Origins of Life and Death examines this question and its possible answers through the lens of the coevolution hypothesis.
“When you start thinking about why death exists, you automatically start to ask what life is because life and death are obviously linked,” he says.
In essence, living beings harbour potential death programmes (versions of death mechanisms that are heritable) and the question of why an organism would actively kill itself is a challenge to evolutionists.
Durand argues that life and death coevolved. “The evolution of more complex cellular life depended on the coadaptation between traits that promote life and those that promote death,” says Durand.???
“Without death, we wouldn’t see life the way we do, and we probably wouldn’t have evolved beyond the very simplest life forms.”
The coevolution hypothesis
The coevolution hypothesis is one of five major hypotheses attempting to explain the evolutionary origins of heritable forms of death – each with varying degrees of empirical support (the hypotheses being Durand’s coevolution hypothesis and the “addiction”, “immunology”, “non-adaptive/mal-adaptive” and “original sin” hypotheses).
One of Durand’s Master’s graduates, Sori La, in 2022 published a paper in the Journal of Molecular Evolution that supports the original sin hypothesis, titled The Ancient Origins of Death Domains Support the “Original Sin” Hypothesis for the Evolution of Programmed Cell Death.
Says Durand: “The emergence of life in the ‘original sin’ hypothesis posits that because of the emergence of life we are forever connected to programmes for death. Life and death programmes are mechanistically linked. These genetic programmes for death seem to be extremely ancient, but we don’t know when they first emerged.”
By comparing the genomes of modern organisms, La found that some of the proteins involved in death today trace back to the very beginning of life.
“This shows that many of the programmes for death may be as old as life itself and emerged very soon after life emerged.”
Evidence for one hypothesis does not prove another wrong, he adds. It’s possible that the evolution of some cells proves one hypothesis, others prove another, and yet others show traits of more than one hypothesis.
“We don’t know,” says Durand. “We will never have an absolute answer because the scientific method used is inductive reasoning – we don’t have access to those very first organisms, so we study today’s organisms and try to trace components of the available genomes as far back as possible. In this field, one hardly ever gets deductive proof, only inductive support for the hypothesis.”
Still, a clearer picture is emerging, with every new study adding a clue. Some of them close one loop but open another that require scientists to conceptualise new questions.
The philosophy of death
For Durand, the work is satisfying a curiosity that he has had since his childhood. “Even as a child I can remember being interested in these questions, but I didn’t know how to ask the questions or even if this field existed. Very few people work on the philosophy of death worldwide.”
Durand has won a fellowship to work with eminent philosopher Grant Ramsey at the Institute of Philosophy at KU Leuven in Belgium, where he will dedicate a year of research time to the philosophy of death.
Though the field is small, the work is significant – some of it is being conducted by emerging researchers such as La, Karen Houlston (PhD candidate) and Jaganmoy Jodder (postdoctoral research fellow) under Durand’s guidance.
“Every student and postdoctoral researcher who has worked in my lab has contributed something significant. They all have an insatiable curiosity and I’m inspired to be working with them. As a team, our interests are two-fold: understanding the evolution of death and developing a general philosophical and metaphysical framework that explains it. It’s a tremendous claim to say that we’re getting some of the answers, but I believe that we are.”
So why do we and other organisms die? “In a metaphysical sense, death is a necessary feature of living systems. Death is a necessity for the sustainability of life. For life to take hold, to evolve, and for us to experience the spectrum of life from the mundane to the truly profound, death must exist. That, at least, is what we’re trying to understand, and it seems to be the answer.”
Associate Professor Kevin Behrens, Director of the Steve Biko Centre for Bioethics at Wits brings a bioethical eye to the philosophy of life and death:
“Without death there would be no life”. If this is true, it follows that we cannot value our life if we do not, also, value our death. One ethical implication of this, is that modern medicine ought to give much more attention to preparing practitioners to deal with death and the dying, and needs to let go of the notion that prolonging life at all costs is always best. Our medical expertise has led to people living longer and healthier lives than ever. However, it has also medicalised dying, with many people coming to the end of their lives in institutions, separated from the people and things that make their lives most meaningful. As American surgeon, writer, and public health researcher Atul Gawande puts it in Being Mortal, “the waning days of our lives are given over to treatments that addle our brains and sap our bodies for a sliver’s chance of benefit.” The oldest ethical principle of the practice of medicine is “first do no harm”. Practitioners need to learn that death is not failure – it is natural. A good, dignified death, when the time for life to end has come is often far less harmful than pursuing every possible treatment, however unlikely they are to be of benefit.
- Delia du Toit is a freelance writer.
- This article first appeared in?Curiosity, a research magazine produced by?Wits Communications?and the?Research Office. Read more in the 14th issue, themed: #足球竞彩app排名 where we celebrate a century of research excellence that has shaped today and look forward to how our next-generation researchers will impact the next 100 years.