Evolution 1

Question 1

Types of lifestyles:

Answer 1

1. Cursorial
2. Aerial
3. Arboreal
4. Saltorial
5. Fossorial
6. Aquatic locomotion

Question 2

Cursorial

Answer 2

• limbs adapted for running
  1. Bones from carpals/ tarsals often fused —> run into toes to reduce contact with ground and friction
  2. Tibia/ fibula and ulna/ radius = long —> lever to increase efficiency of motion

Question 3

Aerial

Answer 3

• limbs adapted for flight
  1. Forelimb modified into wings
• BIRDS: carpals and metacarpals fused
• BATS: rather than digits lost—> lengthened with flap of skin in between

Question 4

Arboreal

Answer 4

• adapted for life in the trees
  1. Digits adapted for grasping so animal can swing through the trees
  2. Wrist and ankle s have little fusion to increase flexibility

Question 5

Saltorial

Answer 5

• limbs adapted to jumping
  1. Hind limbs = lengthened —> act as over during jumping, and muscular —> for thrust
  2. Digits of hind limb (toes) = linger for stability and balance
  3. Forelimbs = smaller —> used for landing and/or feeding

Question 6

Foot posture:

Answer 6

1. Plantigrade
2. Digitigrade
3. Unguligrade

Question 7

Plantigrade

Answer 7

Squirrel

Question 8

Digitigrade

Answer 8

Dog

Question 9

Unguligrade

Answer 9

Deer

Question 10

Tetrapod

Answer 10

Four limbs

Question 11

Fossorial

Answer 11

• adapted for burrowing or digging
  1. Humerus = strong and solid —> acts as shock absorber
• attachment to collar bone and scapula modified to allow animal to push soil from the front to the sides allowing forward motion
  2. Digits = thickened and strengthened —> acts as paddles for moving through soil
  3. Often plantigrade —> wall flat-footed
  4. Live predominantly underground

Question 12

Aquatic

Answer 12

• adapted for life in water
• limbs adapted for swimming
  1. Forelimb - modified to flippers —> act as paddles to propel
  2. Flipper = flattened —> reduces friction —> allows for galloping motion rather than sinusoid all as in fish
  3. Hind limb normally lost