How was roman slaves bought and sold? ?

answer:   migrations were important in the neolithic period. "two major migrations passing through southeastern europe were confirmed by the means of archaeo-genetic studies."

the first migration was the early neolithic period -- 6,000 before common era (bce) -- when the first farmers, from anatolia -- asia minor -- spread through europe. the second migration occurred during the early bronze age (3,000-2,500 bce) when the so-called "steppe population," from the eurasian steppe, replaced much of northern europe's previous population.

the first farmers of northern and western europe passed through southeastern europe with limited hunter-gatherer genetic admixture, which occurs when two or more previously isolated populations begin interbreeding. however, some groups that remained mixed extensively -- without the male-biased, hunter-gatherer admixture that prevailed later in the north and west, according to latest discoveries. southeastern europe continued to be a nexus between east and west, with intermittent genetic contact with the steppe people up to 2,000 years before the migrations that replaced much of northern europe's population.

"in some places, hunter-gatherers and incoming farmers seem to have mixed very quickly," says iain mathieson, a geneticist at the university of pennsylvania, who was first author of the paper. "but, mostly, the two groups remained isolated, at least for the first few hundred years. these hunter-gatherers had been living there for thousands of years, and it must have been quite a shock to have these new people show up -- with a completely different lifestyle and appearance."

the vast majority of ballots have been counted nearly two weeks after one of the biggest political upsets in modern u.s. history catapulted donald trump to the presidency.

estimates show more than 58 percent of eligible voters went to the polls during the 2016 election, nearly breaking even with the turnout rate set during the last presidential election in 2012, even as the final tallies in states like california continue to be calculated, according to statistics collected by the u.s. elections project.

but among those figures were stark contrasts in key states that swing the election to trump — in ohio, wisconsin, iowa, michigan and elsewhere — indicating the president-elect’s leap from long-shot candidate to the most powerful political position in the world may have happened in part because of apathy toward hillary clinton’s candidacy, especially among the democratic base, several political scientists and organizations monitoring voter turnout told the pbs newshour.

while clinton is leading the popular vote by more than 1.5 million over trump as of sunday, she trails president obama’s 2012 totals by more than 2 million ballots — a chasm that may have cost her the election, said david becker, co-founder of the center for election and innovation and research.

“several million voters didn’t come out to vote,” becker said. “which is telling me that this idea of the trump wave, a huge number of voters shifting over to trump, is certainly not the story.”