These penguins are all members of the species Aptenodytes patagonicus. A very large group of penguins of the species Aptenodytes patagonicus is seen standing on land. What is the difference between a species and a population? A species includes only one type of organism, while a population includes many types of different organisms. A species includes only organisms that can reproduce together, while a population includes groups of organisms that cannot all reproduce together. Organisms of the same species must live in similar climates, while organisms of the same population can live in different ecosystems with different climates. Organisms of the same species can live in different areas, while organisms of the same population live in only one area.