Krishna
This book explains evolution through a “ gene’s viewpoint”. Quite an interesting angle. We have reviewed many other books of this author : For instance, see The Ancestor’s Tale or The God Delusion for just two examples.
Except for The God Delusion (at least as far as I know) all of his other famous books deal with the subject of evolution but he presents different facts or perspectives in each one to make them worth reading. In addition, his lucid writing style with an underlying tone of humour is always fun to read.
In addition, you read this for the nuggets of either science or the natural world too, which are strewn all over the book. For instance, in this book, he talks about blackheaded gulls, which nest in large colonies, the nests often only a few feet apart. When a blackheaded gull turns its back on its own nest (perhaps to catch some fish for the young), another gull swoops down and swallows a chick whole – easy nutrition without the effort to catch some fish! And how a praying mantis decapitates the male after coupling. And if this happens during coupling, the coupling proceeds to its climax! Fascinating tidbits in addition to the central theme.
Or emperor penguins trying to push another one into the water (when they are standing on the brink) to ‘test’ if there are seals in the water. If the other one survives being eaten immediately, the water is safe to dive in!
The author moves then to the main point, where he defines ‘selfish’ from the viewpoint of a gene, the basic building block of all life.
What follows is an exciting definition of how life could have formed on earth. He talks about the primordial soup that existed on a young earth and how an energy form such as lightening could have formed a ‘replicator’. These copied themselves, being replicators and both the formation and the improper copying resulted in multiple replicators (not necessarily alive replicators). What followed is ‘evolution’ or competing for dominance to survive in that primitive world – which invariably led to more complex strategies and several thousands of millions of years later, complex organisms including humans. This is not so farfetched, argues Richard, as scientists have seen amino acids form in flasks when the ‘primordial soup’ conditions were replicated there and catalyzed through electricity.
He then goes on to describe a ‘gene’. This is a bit of chromosome (a bit of a protein chain really) that survives intact for many generations through the genetic mix of procreation. He lays the groundwork on how the genes create a new organ called brain with enough information to respond to any threats that may come the organism’s way (that is the animal including human, through which it propagates itself). The genes have no direct say in how the organism responds and wrong choices (including wrong instructions in building the body – perhaps due to changes in the weather or topography or new predators) simply means that this particular organism will not survive and become extinct.
He goes on to discuss how altruism, in some cases, will benefit the gene, if not the body it inhabits and explains affection between close relatives – not just the children – in terms of how many genes they share with you and therefore explains why you are programmed to love your close relatives – in general.
He talks about natural population control (in animals where the society does not look after the discards like humans do) and talks about an optimum brood size, which keeps the overall animal population under check.
Along the way, you get a lot of tidbits about evolutionary behaviour that is either strange or outright shocking : honey guide birds, like cuckoos, lay their eggs in other birds’ nest. Those eggs hatch and the chicks, who are out first, use their sharp beaks to blindly (their eyes are not open yet) slashes all his/ her foster brothers and sisters to death so he has the parental attention all to himself/ herself! Similarly the cuckoos of Britain lay their eggs and they have a shorter incubation period and as soon as they are out, they blindly but ruthlessly efficiently push all the other eggs in the nest down so that they are the lone survivors when the parents, foraging, return!
In experiments, swallows seem to – when the first chick is born – seen to throw out other eggs in the nest – a kind of fratricide to get a larger share of the meal that mommy will bring!
Some of the explanations – although an attempt at simplification – sound a bit elementary and also a bit artificial. For example the points awarded to various kins based on how much of your genes they share and how “attached” you may feel towards them. (Yes, I know that this is not a conscious decision making and this is used only to explain what is programmed into you with no conscious thought on your part) and at least to me, it takes away from the flow of the powerful arguments that pervade the rest of the book.
He explains how seemingly altruistic gestures (bird which chirps to warn others in the flock of a predator presence, seemingly calling attention to itself in the flock or a gazelle jumping high to warn the herdmates of a nearby predator) are really explainable through the selfish gene theory.
More tidbits : Honeypot ants have some ants who fill their belly with honey to a swelling extent and just hang from the ceiling all their life so that others can drink from their store of honey.
All social insects – bees, wasps, ants – all except termites, really, which have a different trait – belong to the species hymenoptera. The queen (in most) goes out and mates one day and then returns to the hive. She stores all the sperms in her for the rest of her life and uses them to produce eggs. Unfertilized eggs become males and fertilized ones become females (Males have only one set of chromosomes, from the mother, unlike for example, humans). Fertilized ones are all females and it is their diet that makes them a queen, or worker (or in terms of ants, guardian ants). Fascinating.
But the main story becomes draggy and boring talking in detail about prisoner’s dilemma and how strategies perform in them. The point is valid that in all animals, there is a need to trust (cooperate) and cheat (defect) and the prisoner’s dilemma is a neat encapsulation to study which behaviour is evolutionarily stable. The problem comes in the vary detailed descriptions – sometimes with repetition – that tests your patience.
You learn about how the fig fruit is not really a ‘fruit’ but a holder of flowers. There is a tiny hole in the fig and only fig wasps are small enough to go and pollinate them. (They are very tiny and so don’t worry if you happen to eat one of them as you are eating the fig! In return, the fig allows them to lay their eggs inside and the larva then can eat some of the flowers) If a ‘cheater’ wasp comes in to lay eggs and not pollinate enough flowers, the fig tree ‘hits back’ in a remarkable way! (Read the book to find out how). Similar example of the sea bass (which alternately plays male and female in its monogamous coupling with another bass) and the one about vampire bat ‘altruism’ are also fascinating.
Shorn of the technical language (and after reading so much about a single subject, some of you, like me, may want to strip out the technology) there are other fascinating examples of how a gene may affect genes outside of its own body : parasitic flukes (flatworms) make a snail grow thicker shells than normal. It may sound like a good thing for the snail but in the long run, it is not good for snailkind. (Again, please read the book to know why). Similarly, a parasite called Nosema stops flour beetle larvae from turning into adults, which is good for the parasite and definitely not for beetles.
Sacculina, a parasite of crabs manages to chemically castrate (render infertile) both male and female crabs so that the energy the crab would have spent on reproduction is instead spent on making the crab fatter, to the benefit of Sacculina.
There are beneficial symbiosis as well: wood boring beetles are parasitized by a bacteria which help in the creation of the beetle’s progeny!
He speculates that the flu virus may be inducing cough to propagate faster and rabies virus makes dogs ferocious as rabies travels by bite! (He speculates because these are unproven theories)
Cruel nature examples are there too. An ant species called Bothriomyrmex regicidus (yes, you heard right!) parasitize other ant species. The queen steals into a rival (and different species) ant colony and attaches itself to the queen. Then it slowly cuts off the head of the victim. The other workers consider her the queen now and tend to her eggs some of whom become workers themselves. This way the intruder’s progeny takes over the whole colony until some of her daughters fly off to find another queen ant to murder and take over. Another species mind controls the workers of a rival colony, again a different species, and makes them murder their own mother, the original queen, and accept her as the new queen. Scientists do not know how exactly it is done but suspect chemical action.
The caterpillar of a butterfly species called Thisbe does what seems like magic! It has a sound-producing organ on its head with which it ‘calls’ ants – it usually lives inside an ant colony while a caterpillar – and spouts at its rear end exuding nectar. It has other glands which can control ants into aggressive behaviour on everything except itself!
When the book gets occasionally pedantic and boring, as these books will, it is such examples that keep you reading and reawaken your desire and wonder and make you continue to the end.
He ends with a very short summary of his other book, The Extended Phenotype (not as an additional hook to read but within the book itself)
An interesting read indeed. I think it deserves a 7/10
== Krishna