...Now, chemical analysis has revealed that the men were far from home when they were killed, up to several days’ journey from where they were born and raised. The discovery is only the most recent example of violence among prehistoric hunter-gatherers in the region, anthropologists say. But it bears important lessons about the nature of conflict and warfare in pre-contact California... The grave was unearthed in 2012 during the construction of a shopping center in the town of Pleasanton, in the Amador Valley just east of Oakland... One of the men suffered a severe blow above the left eye, causing...