By Maddie Rosen

Source: http://tiktaalik.uchicago.edu/book-tools.html

Hands, Hands Everywhere!27 bones34 muscles48 nerves

Source: http://www.presentationgroup.com/medicallibrary/

Manufacturing LimbsRecipe for a limb:

One Bone upperTwo Bones lowerNine bone wristFive finger rods

Exceptional Similarities

Source: http://tiktaalik.uchicago.edu/book-tools.html

Origin of LimbsLepidosiren

paradoxaEusthenopteronIchthyostegaAcanthostega

gunnari

Source: http://tiktaalik.uchicago.edu/book-tools.html

TiktaalikFin with Owen’s

patternEnvironment

Source: http://tiktaalik.uchicago.edu/book-tools.html

DiscussionWhy do you think a limb is set up the way it is? If

you were to create a limb would you use more or less bones? Which areas of the arm would you change?

What do you think Tiktaalik used its advanced arms for? Do you think it was mostly a mud-dwelling or water-dwelling animal? Why?

What do you think lead to the change in lifestyle from fish to Tiktaalik?

Why do you think we evolved to be land dwelling creatures and not an intermediate like Tiktaalik?