Along the Chiapas coast , charcoal levels increased after 3500 BCE .
Along the Chiapas coast , charcoal levels remained high until 2600 BCE when people began abandoning coastal sites , which has been connected with forest clearing through burning .
Along the Chiapas coast , charcoal levels increased after 3500 BCE and remained high until 2600 BCE when people began abandoning coastal sites , which has been connected with forest clearing through burning .