The awesome power that genetic engineering will one day place in our hands was foreshadowed recently by some experimenters at the University of Basel in Switzerland. Walter Gehring and his students were studying the effects of the eyeless gene in fruit flies. The gene is called eyeless because its absence causes flies…
The analogies between the genetic evolution of biological species and the cultural evolution of human societies have been brilliantly explored by Richard Dawkins in his book The Selfish Gene. The book is mainly concerned with biological evolution; the cultural analogies are only pursued in the last chapter. Dawkins's…
I have been a bit negative about memes, but they have their cheerful side as well. When we die there are two things we can leave behind us: genes and memes. We were built as gene machines, created to pass on our genes. But that aspect of us will be forgotten in three generations. Your child, even your grandchild, may…
Memes and genes may often reinforce each other, but they sometimes come into opposition. For example, the habit of celibacy is presumably not inherited genetically. A gene for celibacy is doomed to failure in the gene pool, except under very special circumstances such as we find in the social insects. But still, a…
It is possible that this appearance of non-particulateness is illusory, and that the analogy with genes does not break down. After all, if we look at the inheritance of many genetic characters such as human height or skin-colouring, it does not look like the work of indivisible and unblendable genes. If a black and a…
We are survival machines, but 'we' does not mean just people. It embraces all animals, plants, bacteria, and viruses. The total number of survival machines on earth is very difficult to count and even the total number of species is unknown. Taking just insects alone, the number of living species has been estimated at…
Fossil bones and footsteps and ruined homes are the solid facts of history, but the surest hints, the most enduring signs, lie in those miniscule genes. For a moment we protect them with our lives, then like relay runners with a baton, we pass them on to be carried by our descendents. There is a poetry in genetics…
Identifying genetic variants influencing human brain structures may reveal new biological mechanisms underlying cognition and neuropsychiatric illness. The volume of the hippocampus is a biomarker of incipient Alzheimer's disease1, 2and is reduced in schizophrenia3, major depression4 and mesial temporal lobe…
In a very real sense human beings are machines constructed by the nucleic acids to arrange for the efficient replication of more nucleic acids. In a sense our strongest urges, noblest enterprises, most compelling necessities, and apparent free wills are all an expression of the information coded in the genetic…
Vestigial genes can go hand in hand with vestigial structures. We mammals evolved from reptilian ancestors that laid eggs. With the exceptions of the “monotremes” (the order of mammals that includes the Australian spiny anteater and duck-billed platypus), mammals have dispensed with egg-laying, and mothers nourish…
Another curious tale of dead genes involves our sense of smell, or rather our poor sense of smell, for humans are truly bad sniffers among land mammals. Nevertheless, we can still recognize over 10,000 different odors. How can we accomplish such a feat? Until recently, this was a completely mystery. The answer lies in…
And the evolutionary prediction that we’ll find pseudogenes has been fulfilled—amply. Virtually every species harbors dead genes, many of them still active in its relatives. This implies that those genes were also active in a common ancestor, and were killed off in some descendants but not in others. Out of about…
The software, the program. is responsible for organizing hardware, the organism. Yet throughout the process, it is the organism in its various stages of development that has to run the program. In other words, the hardware runs the software, whilst at the same time the software is generating the hardware.
Every animal and plant genome is subject to a constant bombardment of deleterious mutations: a hailstorm of attrition. It is a bit like the moon's surface, which becomes increasingly pitted with craters due to the steady bombardment of meteorites. With rare exceptions, every time a gene concerned with an eye, for…
A Mendelian gene is an all-or-nothing entity. When you were conceived, what you received from your father was not a substance, to be mixed with what you received from your mother as if mixing blue paint and red paint to make purple. If this were really how heredity worked (as people vaguely thought in Darwin's time)…
Let us suppose that women who have many chidren are far too busy to have much social life, and spend most of their time with their partners and family. The few other people they do see are likely to be other mothers with young children who already share at least some of their child-rearing memes. The more children…