Biologist Richard Dawkins came to prominence in 1976 with his book The Selfish Gene. Nearly half a century later, we’re entitled to wonder how the work has held up. In his recent book, Selfish Genes in ICU?, Dr. Michael Jarvis considers that question, asking whether recent findings in biology match the predictions of Dawkins’s selfish gene concept.
Jarvis, who holds a PhD in biology from the University of Cape Town (where he focused on zoology), takes his reader on a historical journey. He first describes the origin of the universe and the history of Earth, and moves on to Darwin’s theory of evolution. Here, he outlines four key points in The Origin of Species, while paying special attention to one challenge Darwin faced: the Cambrian explosion. From there, Jarvis describes Dawkins’s selfish gene concept — the idea that a gene can be seen as a “selfish unit” that exploits an organism to carry out its own process of replication. Stated another way, the selfish gene concept holds that natural selection takes place at the gene level.
In subsequent chapters Jarvis dives into some discoveries that (spoiler alert!) don’t really match with the selfish gene idea. Jarvis does a nice job of laying out the evidence so that the reader can decide what to think.
Teaser on the Human Eye
One of my favorite parts of the book is the sections on biological function and complexity. I won’t give it all away, but here’s a teaser from the section on the human eye:
In the past some scientists suggested that the human eye retina was actually a poor design. Richard Dawkins proposed this argument. In his 1986 book The Blind Watchmaker he concluded that the vertebrate eye is functionally sub-optimal because the retina photoreceptors are oriented away from incoming light.
Jarvis addresses head-on this frequently repeated claim of poor design. He goes on to cite recent discoveries and explains how this new research affects our understanding of the purported “sub-optimal” design. He notes that our retinas contain special Müller cells which funnel light through the optic nerve onto the retina, compensating for any loss of vision related to the “backwards wiring” of the vertebrate retina:
Research by Amichai Labin and Erez Riba from Israel’s internationally recognized Technion – Israel Institute of Technology in Haifa has shown that the surface of the retina also has so-called Müller cells. These cells not only compensate for the light sensitive receptors being “back to front.” Their function actually results in vision being better than it would have been if the light sensitive cells had been the so-called “right-way round.”
An Update on Two Decades
In the final chapters of the book, Dr. Jarvis updates his reader on what the last twenty years have revealed about evolution. His focus here is on the study of epigenetics, orphan genes, Hox genes, mitochondrial DNA, and directed mutagenesis, all shedding light on how genes evolve and whether or not they are units of selection. Throughout, he argues that these recently discovered genetic features don’t fit the selfish gene concept.
Here’s one example from the field of epigenetics. Epigenetics is the study of mechanisms that change gene expression but that are not heritable. Epigenetic mechanisms allow for both behavior and the environment to affect how a gene works. Here’s the problem epigenetics poses for selfish genes: if a gene is the unit of selection, what benefit does a non-heritable change that is only evidenced in the organism have for the unit of selection? Why would such a mechanism ever be selected in the first place? Hence, epigenetics only makes sense in a system-wide context.
Let’s look at one more of Jarvis’s examples: master regulatory genes, aka Hox genes. These genes have the purpose of being master regulators within a system context. Their activation and function depend upon upstream and downstream genes respectively. A master regulatory gene is helpless without its system context. How then could such a gene be a unit of selection? Do master regulatory genes really desire to reproduce more than they do to serve the organism? Is there evidence for that? Definitely not.
Into the Melting Pot
In gentle fashion, Jarvis lays out numerous pieces of evidence that jeopardize Dawkins’s view that genes are selfish and act as the units of selection. That makes this book the perfect gift for an inquisitive friend who might not be familiar with some of the recent challenges to Dawkins’s ideas.
Jarvis concludes that “selfish genes are in the ICU” and he encourages the reader to place recent discoveries into what he calls a melting pot — a place where many different people and ideas exist and often produce something new. He concludes with a question to the reader: “Are you and I ready for a new theory of evolution that may be as difficult to accept as were the revelations of Albert Einstein?”