While students were quietly taking a quiz, I worked on some numbers. Here are travel times to Proxima Centauri (closest star system; no planets known there as yet) and Gilese 667Cc, where yesterday it was announced there is a planet potentially habitable for us primates. I highlight the rows for traveling at .03 the speed of light because between 1869 and 1969 we increased human travel speed by a thousandfold, from a locomotive's 30mph to Apollo X's c.30,000mph. If we can do the same in the next century, these travel times become comprehensible. 'Generations' indicates simply 30-year human generations. For Prox Cent, it's only 5 generations = about from you to the Civil War. For Gilese 667Cc it's from today to, say, the time of Medieval Europe, Ankor Wat, or the Maya world.
Based on what we know of human biocultural evolution to date, for the longer trip, 700+ years, we can expect (or we might say 'should not be surprised by') some grammatical change in language, perhaps leading to a new language(s); significant changes to human physiology and genetic regulation schedules (though not necessarily very visible physical changes); significant cultural change (new priorities, on the level of religious beliefs and essential philosophies; Rappoport's term 'Ultimate Sacred postulates' is useful here); and tremendous technological advance -- I imagine growing technology--harnessing the replication fidelity of DNA--rather than building it.
