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Margulis believes that mitochondria were originally parasites (or predators - the distinction is not important at this level) which attacked the larger bacteria that were destined to provide the shell of the eucaryotic cell. There are still some bacterial parasites that do a similar trick, burrowing through the prey's…
Imagine a spaceship full of sleeping explorers, deep-frozen would-be colonists of some distant world. Perhaps the ship is on a forlorn mission to save the species before an unstoppable comet, like the one that killed the dinosaurs, hits the home planet. The voyagers go into the deep-freeze soberly reckoning the odds…
[Motoo Kimura] has been the chief advocate of the neutral theory of evolution. The neutral theory says that, through the history of life from beginning to end, random statistical fluctuations have been more important than Darwinian selection in causing species to evolve. Evolution by random statistical fluctuation is…
It is logically possible to postulate organisms composed of pure hardware, capable of metabolism but incapable of replication. It is possible to postulate organisms composed of pure software, capable of replication but incapable of metabolism. And if the functions of life are separated in this fashion, it is to be…
The day will come, says Spencer, when altruistic inclination will be so well embodied in our organism itself that people will compete for opportunities of self-sacrifice and immolation. When altruistic inclinations are implanted in everyone, how will opportunities arise to apply them? Either such a state presupposes…
To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree. When…
Nye did not win, because he was fighting the wrong war. Nye argued like a scientist. He presented the evidence, gave logical explanations, and generally relied on demonstrable facts. He did a flawless job, but changed absolutely no-one's mind, because anyone who cares about science, reason and evidence already accepts…
"The project was cancelled," said Nessus. "We found that the Man-Kzin wars put sufficient restriction on kzinti expansion, made you less dangerous. We continued to watch. "Six times over several centuries, you attacked the worlds of men. Six times you were defeated, having lost approximately two-thirds of your male…
Control of fire and the capacity for cooking led to major anatomical and residential changes for early humans, starting more than a million years ago. However, little is known about what transpired when the day was extended by firelight. Data from the Ju/’hoan hunter-gatherers of southern Africa show major differences…
The metabolic costs of brain development are thought to explain the evolution of humans’ exceptionally slow and protracted childhood growth; however, the costs of the human brain during development are unknown. We used existing PET and MRI data to calculate brain glucose use from birth to adulthood. We find that the…
In most mammals, the mother’s blood supply remains safely isolated from the foetus. It passes its nutrients to the foetus through a filter, which the mother controls. The mother is a despot: she provides only what she chooses, which makes her largely invulnerable to paternal manipulation during pregnancy. In primates…
In proportion as physical characteristics become of less importance, mental and moral qualities will have an increasing importance to the well-being of the race. Capacity for acting in concert, for protection of food and shelter; sympathy, which leads all in turn to assist each other; the sense of right, which checks…
As a species, humans manifest a quality called neoteny, the retention of juvenile characteristics into adulthood. Neoteny has physical ramifications—scarce body hair and a flat face are two examples—but it also has neurological ones. Namely, we have an extraordinary capacity to continue learning throughout life. If…
The ancestors of modern North American bears evolved in Asia during the Pleistocene, wandering over to Alaska during several appearances of the Bering land bridge, between the Bering and Kamchatka Peninsulas. Advancing and receding glaciers, fueled by evaporating sea water, caused ocean levels to alternately drop and…
Each year around Christmas time, green turtles (Chelonia mydas) leave their shallow feeding grounds along the coast of Brazil and embark upon a 2000 km journey to their nesting grounds, the beaches of Ascension Island, in the mid-Atlantic. The journey takes a little more than 2 months in both directions, and is a…
We know, historically, that the "walled garden" approach can have benefits during the early adopter phase. AOL's walled garden provided parental controls, security and organization of online content that was useful to introduce the Internet to mass adoption. But, as we know from IBM, AOL, Microsoft, Apple, etc…
Just as Darwin discovered the law of evolution in organic nature, so Marx discovered the law of evolution in human history; he discovered the simple fact, hitherto concealed by an overgrowth of ideology, that mankind must first of all eat and drink, have shelter and clothing, before it can pursue politics, science…
There was once a brainy baboon, Who always breathed down a bassoon, For he said, 'It appears That in billions of years I shall certainly hit on a tune'.
If we lapse into thinking of the prebiotic, pre-reproductive world as a sort of featureless chaos of chemicals (like the scattered parts of the notorious jetliner assembled by a windstorm), the problem does look daunting and worse, but if we remind ourselves that the key process in evolution is cyclical repetition (of…
Every vitamin is made by living cells — either our own, or in other species. Vitamin D is produced in our skin, for example, when sunlight strikes a precursor of cholesterol. A lemon tree makes vitamin C out of glucose. Making a vitamin is often an enormously baroque process. In some species, it takes 22 different…