Mystery of Brownian Motion Through History

Number of words: 340 Centuries ago, the Scottish botanist Robert Brown became fascinated by the zigzag motion of fragments within pollen grains. In his pioneering observations, made with a primitive microscope, Brown had spotted this random jittery motion as early as 1827. What puzzled him was that this incessant movement did not arise from currents … Read more

Cultural Adaptation in the Pacific

Number of words: 284 Natural selection can act on human culture as well as on genes. Some scholars have scoffed that a scientific theory of cultural evolution that aims to ape Darwinian evolution is impossible because human beliefs and behaviors are so unpredictable and subject to historical contingencies as well as sudden breakthroughs, discoveries, and … Read more

The Interplay of Cooperation and Community Development

Number of words: 222 The very fact that people decide to live in the same patch, rather than dotted around at random, has to do with cooperation. Why? Some believe, for example, that the first communities evolved as a result of success in agriculture: surplus food from farming enabled people to settle down and specialize, … Read more

Public Acts in Indirect Reciprocity

Number of words: 251 Karl also had plenty of anecdotes to underline why indirect reciprocity is just as relevant to everyday life as the direct version of reciprocity. He pointed out that the Rothschild family had protected the investments of their English clients during the Napoleonic Wars. They were under intense pressure to give them … Read more

The Power of Reputation in Indirect Reciprocity Dynamics

Number of words: 625 Exploring the indirect form of reciprocity is important because it is critical for society. Direct reciprocity—“I’ll scratch your back and you scratch mine”— operates well within small groups of people, or in villages where there is at ightknit community where it would be hard to get away with cheating one another. … Read more

The Rise and Fall of Strategies in Evolutionary Tournaments

Number of words: 691 Now Karl and I could sit back and watch the strategies slug it out in our creation over thousands and thousands of generations. Our fervent hope was that one strategy would emerge victorious. Even though no evolutionary trajectory ever quite repeated itself, there were overall patterns and consistency in what we … Read more

Intriguing Relationship Between Cleaners and Clients

Number of words: 324 The bats are one often cited example of direct reciprocity in nature. Another can be found on coral reefs, where fish of all kinds visit “cleaning stations” where they are scrubbed of parasites by smaller varieties of fish and by shrimps: the former get cleaned of pesky parasites and the latter … Read more