Human Arm
Bird Wing
Biological Diversity— “Biodiversity”:
Biodiversity describes all of the different forms of life on Earth as well as all the natural
processes. As you can see, birds have many different colors, shapes, weights, wingspans and
diets. Ecosystems need a lot of biodiversity to be strong, or resilient. What might happen if
we lost one species, such as the Kirtland’s warbler?
Adaptation:
Adaptations are special body parts or behaviors that help an animal survive. Human
bipedalism, or standing upright, is an adaptation. The flight of birds is also an adaptation,
made possible by their feathers and light skeleton. Can you think of any other bird
adaptations?
Homology:
Two structures are considered homologous if they are similar in structure because of shared
ancestry. Vertebrate ‘arms’ are all very similar, consider the bones in a bird’s wing and the
bones in your own arm. Can you find the radius in both diagrams—human and bird?