Nat Geo has a dope article this month.
The idea is that when a group of individuals decides to leave a place and settle a new one, there are certain characteristics of said individuals that will have incentive to proliferate through the population at it expands and especially on the outer reaches of the population’s advancing front.
The article chronicles the settlers of Quebec’s Saugenay valley and river system who created farms and small communities farther and farther along the northward pointing river. And those that had the wanton to settle farther and newer fields, begot offspring with the same characteristics. Not only this, but they also had incentive to have families earlier in life which begot them more children and more descendants, again increasing the likelihood their wild, adventuresome genes went on.
In Australia this idea crops up in the length of cane toad’s legs which are advancing across the continent as an invasive species at a whopping 30 miles per year. The average leg length at the advancing front is 10% greater than those of the rest of the population. Pretty wild.
Are you a settler’s descendant, yearning for something wild? Doooo it. Haha.