genome the autobiography of a species in 23 chapters - matt ridley

[...]... of the genetic code are the same in every creature CGA means arginine and GCG means alanine — in bats, in beetles, in beech trees, in bacteria They even mean the same in the misleadingly named archaebacteria living at boiling temperatures in sulphurous springs thousands of feet beneath the surface of the Atlantic ocean or in those microscopic capsules of deviousness called viruses Wherever you go in. .. Mediterranean basin by a gigantic marine cataract at Gibraltar, a cataract one thousand times the volume of Niagara, suddenly isolated a small population of missing links on some large Mediterranean island, where they took to a life of wading in the water after fish and shellfish This ‘aquatic hypothesis’ has all sorts of dungs going for it except hard evidence Whatever the mechanism, we can guess that... set, tat, tea and tee Now eliminate those that can be misread as another word if you start in the wrong place For example, the phrase ateateat can be misread as a tea tea t’ or as ‘at eat eat’ or as ‘ate ate at’ Only one of these three words can survive in the code Crick did the same with A, C, G and T He eliminated AAA, CCC, GGG and TTT for a start He 6 then grouped the remaining sixty words into... look in the cell, the most primitive and basic functions require the presence of RNA It is an RNA-dependent enzyme l8 GENOME that takes the message, made of RNA, from the gene It is an RN A- containing machine, the ribosome, that translates that message, and it is a litde RNA molecule that fetches and carries the amino acids for the translation of the gene’s message But above all, RNA - unlike DNA - can... our ancestor, an ape At that point, ten million years before the present, there probably lived at least two species of ape in Africa, though there may have been more One was the ancestor of the gorilla, the other the common ancestor of the chimpanzee and the human being The gorilla’s ancestor had probably taken to the montane forests of a string of central African volcanoes, cutting itself off from the. .. can act as a catalyst, breaking up and joining other molecules including RNAs themselves It can cut them up, join the ends together, make some of its own building blocks, and elongate a chain of RNA It can even operate on itself, cutting out a chunk of text and splicing the free ends together again The discovery of these remarkable properties of RNA in the early 1980s, made by Thomas Cech and Sidney Altaian,... such a thing to take is a digital message - a number, a script or a word In New Jersey in 1943, a quiet, reclusive scholar named Claude Shannon is ruminating about an idea he had first had at Princeton a few years earlier Shannon’s idea is that information and entropy are opposite faces of the same coin and that both have an intimate link with energy The less entropy a system has, the more information... one; seaweed is your distant cousin and anthrax one of your advanced relatives The unity of life is an empirical fact Erasmus Darwin was outrageously close to the mark: ‘One and the same kind of living filaments has been the cause of all organic life.’ In this way simple truths can be read from the book that is the genome: the unity of all life, the primacy of RNA, the chemistry of the very earliest... terrain; the knuckle-walking of other apes is better suited to shorter distances over rougher terrain The skin has changed, too It is becoming less hairy and, unusually for an ape, it sweats profusely in the heat These features, together with a mat of hair to shade the head and a radiator-shunt of veins in the scalp, suggest that our ancestors were no longer in a cloudy and shaded forest; they were walking... skull, there was no cranial space for the brain Without the slow development, there was no time for learning to maximise the advantages of big brains Driving the whole process, perhaps, was sexual selection Besides the changes to brains, another remarkable change was going on Females were getting big relative to males Whereas in modern chimpanzees and australopithecines and the earliest ape-men fossils, . molecule that fetches and carries the amino acids for the translation of the gene’s message. But above all, RNA - unlike DNA - can act as a catalyst, breaking up and joining other molecules including. proteins. And it is proteins that enable DNA to replicate. To paraphrase Samuel Buder, a protein is just a gene’s way of making another gene; and a gene is just a protein’s way of making another. bacteria. They even mean the same in the misleadingly named archaebacteria living at boiling temperatures in sulphurous springs thousands of feet beneath the surface of the Atlantic ocean or in those