1. Notes: Constraints (pg 14)

2. Notes: Constraints (pg 14)
• Why aren’t airplanes made entirely of “black
box” material?

3. Cost constraints
• In Biology, “cost” means energy cost
• Example: cardiac muscle can contract forever
without getting tired. Why aren’t all our
muscles made of cardiac muscle?

4. Cost constraints
• In Biology, cost means energy cost
• Example: cardiac muscle can contract forever
without getting tired. Why aren’t all our
muscles made of cardiac muscle?
Regular muscle doesn’t NEED to contract all
the time, the heart does
Cardiac muscle contains lots of mitochondria
and uses a huge amount of glucose.

5. Evolutionary constraints
• Evolution works by modifying existing forms,
not designing new organisms (like remodeling
a house instead of building a new one)

6. Evolutionary constraints
• Evolution works by modifying existing forms,
not designing new organisms (like remodeling
a house instead of building a new one)
• Example: Ancestors: 4 legs Humans: 2 legs.
Spine and pelvis were modified.
As a result, humans have back problems and
difficult childbirth