- Evolution: Evolving Species
- Answer the following question:
- How does changes in the environment affect organisms?
- Homework Check
- Fossils: Clues To The Unknown Past.
- Reconstructing a Fossil Pterosaur.
- Answering the Question of the Day:
- Before answering the question, stop and list elements in the environment
that can be easily measured.
- Next ask how changes of each element in the environment affects organisms.
- Every living organisms has a narrow range of temperature, humidity,
pH, salinity, etc. where they thrive. The farther the environment
moves from that range puts stress on the organism, and can result
in their deaths.
- Fossils: Clues To The Unknown Past
- Fossils are usually the remains of hard body parts, such as shells
- Fossilization can happen in several ways, such as carbonization,
- All of the above make direct
evidence for the fossil record.
- Indirect evidence of the fossil record also provides good information.
- Three types or indirect evidence are molds,
casts, and trace
- Trace fossils tells us about what the organisms did through things
like animal tracks, burrows, and borings.
- Reconstructing a Fossil Pterosaur
- Before reassembling the bones of the Pterosaur, write down your basic
assumptions. This is a skeleton, like ours or bird's skeletons, so there
are some very common characteristics of skeletons.
- There is a skull.
- There is a vertebrae.
- There are limbs, or appendages.
- The upper arm and thigh have only one bone, the humerus and femur
- The forearm and lower leg have two bones, the ulna and radius,
and the tibia and fibula respectively.
- The hands and feet have about 20 bones each, three phlanges and
one carpal or tarsal.
- The hands are attached to the arm bones.
- The feet are attached to the leg bones.
- The arms are attached to the pectoral girdle.
- The legs are attached to the pelvic girdle.
- Now remember that evolution if very conservative. New parts will not
appear. Parts will simple be restructured, such as longer fingers, and
- Now lets check your Pterosaur.