BIOD43H3 Lecture Notes - Lecture 16: Terrestrial Locomotion, Phosphate, Quadrupedalism
Lecture 16: Evolution of Flight Notes
• Vampire bats behave much more like four-legged terrestrial mammals, in that they like
to walk around on the ground; other bat species fumble helplessly when left to walk
- Ex. The Insect Bat can walk but when it does it looks lame.
• Therefore, Vampire bats mainly have highly specialized terrestrial locomotion to get
around. They approach prey that is on the ground.
• When walking the vampire bat lift their hind limbs (back legs) off the ground first
- swinging with their front limbs on the ground; like walking with crutches
• Bounding Gait! a form of legged locomotion generally observed when a quadruped
animal is running at the highest speed. Here both legs are off ground
Evolution of Flight
• Trees Down Hypothesis
-There are flying snakes, lizards and squirrels that have adapted a strategy of gliding in
the air as a way of locomotion
-Proto birds, bird-like dinosaurs that once existed
-True birds (today’s birds) and protobirds co-existed
-Flying/ gliding may have resulted from ‘Directed Aerial Descent’ (DAD), where falling
animal finds a way to enhance their surface area by spreading out arms and legs and
angling toward surface appropriate for landing.
• Ants have adapted DAD
• However, before gliding from trees and other high levels, there must be adaptations for
climbing .
• Climbing is a prerequisite for arboreal gliding.
• Non-avian birds cluster near other animals that run around the ground, not with animals
that climb trees
• Ground Up Hypothesis
-Juvenile Chukar birds get increasing better at generating thrust and lift as they age
• It is not clear which hypothesis is true; however, both are one of the same. You can not
have one without having the other (if one is true so is the other).
Measuring Metabolic Rate:
1) 31P‐NMR Spectroscopy
- Measures ATP TURNOVER (detects shift between ATO and inorganic phosphate)
- Measures cellular energy currency, and is accurate for short time (measuring a single
muscle contraction)
- However, is logically difficult and subject must be restrained
2) Direct Calorimetry:
-Measurement of heat from chemical/physiological process
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Vampire bats behave much more like four-legged terrestrial mammals, in that they like to walk around on the ground; other bat species fumble helplessly when left to walk. The insect bat can walk but when it does it looks lame: therefore, vampire bats mainly have highly specialized terrestrial locomotion to get around. They approach prey that is on the ground: when walking the vampire bat lift their hind limbs (back legs) off the ground first. Swinging with their front limbs on the ground; like walking with crutches: bounding gait! a form of legged locomotion generally observed when a quadruped animal is running at the highest speed. There are flying snakes, lizards and squirrels that have adapted a strategy of gliding in the air as a way of locomotion. Juvenile chukar birds get increasing better at generating thrust and lift as they age. It is not clear which hypothesis is true; however, both are one of the same.
