Its tech only incest by def w/ in 3rd cousin range. Noah, and his family on the ark was not 4 people. It was thier extended family as best I recall. It'd be like you goin to a fam reunion and gettin all those pople together, some you dont even know. Back then, most people never left a 3-5 mile radius they were born in, so they knew thier relatives, and 3rd and 4th cousins were not as close as we make them out to be. They may be as we would refer to as distantly related now.