diff --git a/src/Stats/FossilRecord.js b/src/Stats/FossilRecord.js
index 16e58dd..c33b822 100644
--- a/src/Stats/FossilRecord.js
+++ b/src/Stats/FossilRecord.js
@@ -41,7 +41,9 @@ const FossilRecord = {
                 if (species.cumulative_pop < this.min_pop) {
                     return false;
                 }
-                this.extinct_species.push(s);
+                // disabled for now, causes memory problems on long runs
+                // this.extinct_species.push(s);
+                
                 // console.log("Extant species:", this.extant_species.length)
                 // console.log("Extinct species:", this.extinct_species.length)
                 return true;
diff --git a/src/Stats/Species.js b/src/Stats/Species.js
index 37daadd..f251844 100644
--- a/src/Stats/Species.js
+++ b/src/Stats/Species.js
@@ -3,17 +3,11 @@ const CellStates = require("../Organism/Cell/CellStates");
 class Species {
     constructor(anatomy, ancestor, start_tick) {
         this.anatomy = anatomy;
-        this.ancestor = ancestor;
+        // this.ancestor = ancestor; // garbage collect ancestors to avoid memory problems
         this.population = 1;
         this.cumulative_pop = 1;
         this.start_tick = start_tick;
         this.end_tick = -1;
-        this.color = Math.floor(Math.random()*16777215).toString(16);
-        if (ancestor != null) {
-            // needs to be reworked, maybe removed
-            var mutator = Math.floor(Math.random()*16777215)-8000000;
-            this.color = (mutator + parseInt(ancestor.color, 16)).toString(16);
-        }
         this.name = '_' + Math.random().toString(36).substr(2, 9);
         this.extinct = false;
         this.calcAnatomyDetails();