A living being like you or me usually has two elements: a set of instructions that tell the system how to keep going and how to reproduce itself, and a mechanism to carry out the instructions. In biology, these two parts are called genes and metabolism. But it is worth emphasising that there need be nothing biological…
Of the 20,000 to 30,000 genes now thought to be in the human genome, most cells express only a very small part - which makes sense, a liver cell has little need for the DNA code that makes neurons. But as almost all cells carry around a full copy ('distribution') of the genome, a system is needed to #ifdef out stuff…
When genes are activated, the instructions encoded within their DNA are first transcribed into a related molecule called RNA. Shepherd’s colleague Elissa Pastuzyn showed that the Arc shells can enclose RNA and move it from one neuron to another. And that’s basically what retroviruses do—they use protein shells to…
Having turned my back on propositions, I thought, what am I going to do about this? The area where it really comes up is when you start looking at the contents of consciousness, which is my number one topic. I like to quote Maynard Keynes on this. He was once asked, “Do you think in words or pictures?” to which he…
Take those born with genes that make them a bit taller and quicker than average. When they start school, they are likely to be a bit better at basketball. The advantage may be modest but then reciprocal causation between the talent advantage and environment kicks in. Because you are better at basketball, you are…
For the last decade, the science of aging has increasingly focused on sirtuins, a group of genes that are believed to protect many organisms, including mammals, against diseases of aging. Mounting evidence has demonstrated that resveratrol, a compound found in the skin of grapes as well as in peanuts and berries…
For mankind as a whole, a possession infinitely more valuable than individual life is our genetic heritage, our link with past and future. Shaped through long aeons of evolution, oru genes not only make us what we are, but hold in their minute beings the future – be it one of promise or threat. Yet generic…
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…
Things happen because the laws of nature say they will—because they are the consequences of the state of the universe and the path of its evolution. Life on Earth doesn’t arise in fulfillment of a grand scheme but as a by-product of the increase of entropy in an environment very far from equilibrium. Our impressive…
The in-group-vs.-out-group double standard, which had and has such catastrophic consequences, could in theory be eliminated if everyone alive were considered to be in everyone else’s in-group. This utopian prospect is remote, but an expansion of the conceptual in-group would expand the range of friendly, supportive…
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…
We have altered the environment in a vast number of ways, both small and large. And when animals try to read the cues from our human environment, they can get tricked. They can end up doing something that kills them, loses them the opportunity to reproduce, or simply wastes their time. Scientists call these situations…
What I expect to happen is that my body will fail, my mind will cease to function and that will be that. My genes will not live on, because I have had no children. I am comforted by Richard Dawkins’ theory of memes. Those are mental units: thoughts, ideas, gestures, notions, songs, beliefs, rhymes, ideals, teachings…
The secular philosophies of death that I’ve been writing and reading about and contemplating for years have been a tremendous comfort. For instance: The idea that we didn’t exist for billions of years before we were born—that nonexistence wasn’t painful or bad, and death won’t be either. The idea that our genes and…
Parasites are not only incredibly diverse; they are also incredibly successful. There are parasitic stretches of DNA in your own genes, some of which are called retrotransposons. Many of the parasitic stretches were originally viruses that entered our DNA. Most of them don't do us any harm. They just copy and insert…
Genetics is to biology what atomic theory is to physics. Its principle is clear: that inheritance is based on particles and not on fluids. Instead of the essence of each parent mixing, with each child the blend of those who made him, information is passed on as a series of units. The bodies of successive generations…
No hypothesis concerning the nature of this 'something' shall be advanced thereby or based thereon. Therefore it appears as most simple to use the last syllable 'gen' taken from Darwin's well-known word pangene since it alone is of interest to use, in order thereby to replace the poor, more ambiguous word, 'Anlage'…
The genome is not a blueprint for constructing a body; it is a recipe for baking a body. As the hox story illustrates, DNA promoters express themselves in the fourth dimension; their timing is all. A chimp has a different head from a human being not because it has a different blueprint for the head, but because it…
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…