populations.step

forest http://s0.geograph.org.uk/geophotos/01/98/32/1983266_886d80da.jpg

mangroves http://upload.wikimedia.org/wikipedia/commons/thumb/b/b1/Pichavaram_Mangrove.jpg/512px-Pichavaram_Mangrove.jpg

cool_moth http://upload.wikimedia.org/wikipedia/commons/thumb/d/dd/Brahmaea_wallichii_insulata_%28Brahmeid_Moth%29_wb_edit.jpg/512px-Brahmaea_wallichii_insulata_%28Brahmeid_Moth%29_wb_edit.jpg

violet_bacteria http://upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Bacteria_photomicrograph.jpg/512px-Bacteria_photomicrograph.jpg

chemostats http://upload.wikimedia.org/wikipedia/commons/thumb/3/37/Two_chemostats.png/451px-Two_chemostats.png

gm_caterpillar http://upload.wikimedia.org/wikipedia/commons/1/16/Gypsy_moth_caterpillar.JPG

asian_gm http://upload.wikimedia.org/wikipedia/commons/a/a5/Lymantria_dispar_asiatica_male.jpg

gm_defoliation http://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Gypsy_Moth_Defoliation_Snow_Shoe_PA.jpg/512px-Gypsy_Moth_Defoliation_Snow_Shoe_PA.jpg

cod http://upload.wikimedia.org/wikipedia/commons/1/19/Portrait_of_Cod.jpg

us_malaria_1935 http://upload.wikimedia.org/wikipedia/commons/b/b3/MalariaMap.jpg

red_squirrel http://upload.wikimedia.org/wikipedia/commons/e/e1/Red_Squirrel_-_Lazienki.JPG

grey_squirrel http://upload.wikimedia.org/wikipedia/commons/7/7c/Eastern_Grey_Squirrel_in_St_James's_Park,_London_-_Nov_2006_edit.jpg