Evolution

On multicellularity and slime molds

Human beings are great big conglomerates of millions upon millions of cells. In this respect, we are very similar to other animals, as well as land plants, algae and filamentous fungi — we are multicellular. Multicellularity is thought to have evolved independently several times throughout history. Traditional thinking was that the ancestors of land plants evolved … Continue reading

Evolution

Reproductive quirks (part 2): Why did menstruation evolve?

As I’ve noted previously, humans are strange beasts and our reproductive biology illustrates this well. Menstruation and menopause are both rare in the animal kingdom. Of all mammals, only us, our primate relatives and elephant shrews menstruate. Menopause is even harder to come by — killer whales are our only sisters in hot-flushes, apparently. This … Continue reading

Evolution

The prisoner’s dilemma — how cooperation leads to “survival of the fastest”

You’ve committed a crime. You and your co-conspirator have been nabbed, but fortunately, there’s not enough evidence to put you both away for the time you deserve. You’ll be sentenced to just one year in prison. Unless, that is, you turn on your criminal associate, who will take the fall for a three-year sentence, while … Continue reading