It is a vegetation map. The dark green is conifer forest, the light green is deciduous forest. You can read the article here: http://www.esd.ornl.gov/projects/qen/nercEUROPE.html John O'Grady ---------------------------------------- > From: [email protected] > To: [email protected] > Date: Sun, 5 Jan 2014 19:51:44 -0700 > Subject: Re: [yDNAhgI] 3 ancestral populations for present-day Europeans > > Interesting feature on that map is that swath of darker color that isolates > present-day Poland from Germany. What does the darker color mean? A > different kind of vegetation or soil type? > > > > Kenneth Nordtvedt