What is the main message of The Extended Phenotype?

The main message of The Extended Phenotype is that genes can influence not only an organism's body, but also its environment and other organisms.

How long does it take to read The Extended Phenotype?

The reading time for The Extended Phenotype varies, but it typically takes several hours. However, the Blinkist summary can be read in just 15 minutes.

Is The Extended Phenotype a good book? Is it worth reading?

The Extended Phenotype is worth reading because it offers insights into the role genes play in shaping the world around us.

Who is the author of The Extended Phenotype?

The author of The Extended Phenotype is Richard Dawkins.

The Extended Phenotype Summary of Key Ideas and Review

Name: The Extended Phenotype
Rating: 4.5 (72 reviews)
Author: Richard Dawkins

Introduction

What’s in it for me? Learn about evolution from a genetic perspective.

You no doubt know about Darwinism and the concept behind the “survival of the fittest.” But when you consider who was actually doing the surviving, there’s a good chance that you may have only been thinking about humans or animals.

As it turns out, there’s more than one way to consider Darwin’s theories, and when we only pay attention to what’s going on with big organisms like monkeys and humans, we miss out on a major player in the survival game: genes.

When we zoom in down to the cellular level, we can see how genes are really the ones actively trying to survive. After all, it’s genes that are attempting to survive by supplying you with the ideal hair color, facial features and personality for passing those very same genes on to the next generation.

As the author Richard Dawkins explains, we should really be looking through the microscope and taking note of how competitive genes are, since this is where all the adaptation, mutation and replication is really taking place.

In these blinks, you’ll discover

why there’s no such thing as a “blue-eye gene;”
how an angler fish is more than just super creepy – it’s also a great example of evolution; and
what a snail’s shell can teach us about evolution.

Key idea 1 of 12

When considering evolution, we should think of genes as well as organisms.

Ever since Charles Darwin’s theory of evolution was published back in the mid-nineteenth century, his observations have often been summarized with the popular concept of “the survival of the fittest.” When we imagine how this survival takes place, we take a very specific biological perspective on which organisms are fighting for survival.

When we think of life, we think of the large organisms Darwin wrote about, such as birds, orchids or humans, and we picture these plants and animals as being the selfish ones fighting for their survival.

So, even though we recognize larger units, such as societies, populations and ecosystems, as well as smaller units such as cells and genes when it comes to biological evolution, we almost always talk about “selfish organisms.” Most evolutionary biologists focus their study on the individual body – so for them it's organisms, not populations or genes, that compete and evolve.

But an interesting thing happens when we shift our focus away from the individual bodies toward the genes, and we start thinking about “selfish genes” rather than “selfish organisms.”

Making this shift in perspective is a lot like adjusting the way you look at a Necker cube, which is the name of the typical 3D cube you’ve probably drawn on a piece of paper numerous times. It’s just two overlapping squares, one slightly above the other, with four diagonal lines connecting the corners.

When you look at a Necker cube, you can see it in two different ways, with either the lower square or the upper square making up the front of the cube. But there’s no one correct way of seeing it – both perspectives are equally valid and accurate.

And it’s the same for our biological perspective on what’s fighting for survival: both the organism-centric view and the gene-centric view are valid. So, when we shift to the genetic point of view, we’re not looking at things from a single correct perspective. Instead, we’re opening the door to new questions that go beyond, “Why are certain genes useful to an organism?” Now we can ask, “Why are certain genes often grouped together in organisms?”

In the blinks ahead we’ll further explore these questions and much more.

Key idea 2 of 12

Genes can only influence our lives; they can’t determine our future.

We love a good myth. Whether it’s the legend of the Yeti, Bigfoot or accounts of Elvis Presley being alive and working at a gas station, people cling to such stories and keep them alive for generations.

The field of biology isn’t immune to myths either, and one of them could be called the “gene myth.” This is the misconception which suggests that having certain genes means we’re doomed to live out a specific fate.

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Key idea 3 of 12

Organisms don’t always have optimal traits, which is a sign that Darwin didn’t have the full picture.

The gecko is a fantastic example of the use of evolutionary development for protection, having gained the ability to change the color of its skin so it can hide in plain sight. Whereas sharks, on the other hand, are a good example of predatory development, their skin having become so smooth that it cuts through the water at lightning speed.

But are these traits always the best? If you’re an adaptationist – someone who's taken Darwin's ideas to mean that all organisms evolve to gain traits that are optimal for the problems they face – you’d answer yes. However, if we look around, we can see that many traits are, in fact, not optimal at all.

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Key idea 4 of 12

Organisms will sometimes work against their own interest.

Along with the adaptation of optimal traits, there is another belief surrounding evolution that may not be so accurate. This one is about organisms maximizing their own “fitness.” In other words, this is the central theory that every plant, animal and human will instinctively act in its own best interest to make sure it passes on its genes to the next generation.

Once again, however, we can look around us and see many cases where an organism is actually acting in the best interest of another organism – one that is manipulating it for its own benefit.

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Key idea 5 of 12

Genes are the real replicators, not organisms.

So, let’s return to the main question: What’s behind an organism’s evolutionary drive to compete and thrive?

To get to the bottom of this, we need to first understand what a replicator is.

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Key idea 6 of 12

Organisms are vehicles that carry genes.

Now that we’ve taken a closer look at genes and their role as replicators, let’s look more closely at organisms themselves.

Rather than being replicators, organisms are better defined as vehicles.

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Key idea 7 of 12

Signs of how genes compete can be seen in the “outlaws” and “modifiers.”

Once we recognize the difference between vehicles and replicators, we can start to see that the real active agents of evolution aren’t the organisms, but rather the genes. A more accurate definition of the biological process of natural selection would be: “the process by which genetic replicators outcompete each other.”

Genetic replicators compete through phenotypic effects. These are the different ways in which genes influence an organism’s characteristics, including their physical traits and behavior. So, in a human, this would include hair and eye color and how timid his personality is.

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Key idea 8 of 12

With genes at the center of our biological picture, we can explain our superfluous DNA.

One of the oddities of human biology that has confounded biologists is the fact that we contain way more DNA than is necessary for our bodies to be built and to function properly. In other words, we have superfluous DNA.

But remember, one of the primary reasons biologists have been unable to figure this out is their organism-centric perspective of evolution. From this point of view, the sole purpose of DNA is to supervise the building of an organism’s body and to make sure it functions properly – and for this, the mysterious leftover DNA is indeed superfluous and purposeless.

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Key idea 9 of 12

The various meanings of “fitness” have confused the topic of evolution.

Throughout these blinks, we’ve talked about “survival of the fittest” and how genes and organisms can try to “maximize their fitness.” But what does being fit really mean in scientific terms?

Part of the confusion that has lingered around the field of evolution is that “fitness” tends to be used by biologists in different ways.

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Key idea 10 of 12

The influence of genes goes beyond the individual organism.

We’ve realigned our evolutionary perspective away from the organism and squarely onto the survival of genes, so it’s time to do the same with our understanding of the phenotype.

As we’ve explained in previous blinks, the phenotype is what gives us all our observable characteristics, including our physiological traits, such as hair color, and our behavioral traits and personality. But it’s important to remember that genes combine with an organism’s environment to make the phenotype.

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Key idea 11 of 12

The external influence of genes can result from multiple organisms joined together.

Now you know how to recognize when the influence of an organism’s phenotype extends beyond its own body, you might be wondering: How do I know what is and isn’t an expression of an organism’s phenotype?

When considering what qualifies as an extended phenotype, remember that an extended phenotype needs to be related to things that influence the organism’s survival or chance of reproduction.

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Key idea 12 of 12

In the concept of the extended phenotype, the Necker cube flips.

In this final blink, let’s circle back to where we started, with the visual aid of the Necker cube. This was used to illustrate two equally valid views in biology: the traditional view that emphasized the individual organism and the alternate view that emphasized the genes as the elements competing for survival.

By this point, we’ve seen plenty of examples of the “selfish gene” and how these act in their own interest through their extended phenotype, so it should be easier for you to see both sides of the Necker cube and both perspectives on evolution.

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