(The Moving Animal) Evolution And The Adaptation In Understanding "animal Design"

Front 1

What is adaptation?

Back 1

A trait that enhances fitness and that arose historically as a result of natural selection for its current biological role.

Requires;

- Feature

- More offspring reproducing

- Favoured by natural selection

- Appeared in conjunction with its current function in its environment (was not previously used for another function)

Front 2

How do we apply evolutionary methods to test for adaptations?

Back 2

- phylogenetic comparative methods

Front 3

What are non-adaptive explanations for animal design?

Back 3

- Phylogenetic constraint or "baggage"

- Design constraints prevent the optimal

- Sexual selection

- Neutral features ("spandrels")

- Co-variation with other traits

- Exaptation

- Random genetic drift

Front 4

What are some examples of important evolutionary novelties and constraints in vertebrate locomotor design?

Back 4

Earliest vertebrates:

- Body segments organized into myomeres with blocks of muscle separated by myosepta

- Contracted in waves to propel the body forward

- Pectoral, then pelvic fins evolved to supplement role of axial column in generating thrust and lift

- Both fins gained bony supports that expanded distally in fish closely related to tetrapods

Front 5

What are adaptive features for economy and speed?

Back 5

For economy and speed;

- Continuum of limb posture (Planti/Digiti/Unguligrade)

- Elongation of distal limb for speed

- Lightening of the distal limb to minimise cost of leg swing

- Reduction in number of bones

- Muscle replaced by energy- efficient tendons that act as pulleys and springs

- Motion restricted to sagittal plane

Front 6

What are adaptive features for economy?

Back 6

- High 'aerobic scope' (10-50X in athletic animals (about 5 in lizards))

Temperature regulation; evaporation (sweating, panting), brain temperature regulation (carotid rete)

- Mitochondrial density in muscle

- Red blood cell volume A}

Front 7

What is 'Parasite power'?

Back 7

- The power required to overcome drag on body

Front 8

What is the formulae for parasite power?

Back 8

Front 9

What is 'Profile power'?

Back 9

- The power required to overcome drag on wings

Front 10

What is the formulae for profile power?

Back 10

Front 11

What is 'Induced power'?

Back 11

-The power required due to accelerating air down to support body weight

Front 12

What is the formulae for induced power?

Back 12

Front 13

What is the formulae for aspect ratio?

Back 13

Front 14

What is the orthodox way in which wings generate lift?

Back 14

- All wings generate lift by accelerating air over the upper surface and creating a bound vortex - the result of a sharp trailing edge.

Front 15

What is the unorthodox way in which wings generate lift?

Back 15

- Some wings have sharp leading edges too, which promotes flow separation and high forces at the expense of 'fuel economy'.

Front 16

What defines the way in which a wing is shaped?

Back 16

- Wings are shaped by the ecological pressures imposed upon them, affecting aspect ratio, camber, planform, wing tip design, surface properties, shape changing devices, and more.

Front 17

How do frogs maximise their jump distance?

Back 17

Jump force = mass * acceleration

Takeoff speed = acceleration * duration

So...

Producing more force = faster acceleration

mass * increased acceleration = more force

- Fusion of lower limb bones achieves this

Accelerating for longer = higher takeoff speed

acceleration * increased duration = higher speed

- Elongation of legs due to evolution achieves this

Front 18

What is convergent evolution?

Back 18

- In evolutionary biology, convergent evolution is the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches.

Front 19

Why do frogs have a modified pelvic bones and musculature?

Back 19

- Allow increased spinal flexibility to control takeoff angle

- Enhance force produced against the ground

Front 20

Why do frogs have long, stretchy tendons?

Back 20

- Allow catapult-like jumping; increased power for jumping

Front 21

What structural modifications to meet the functional demand of avoiding crash landing is there?

Back 21

- Absorbing the energy of impact

- Preparing for impact

- Postural ‘reset’ - Getting ready for the next jump

Front 22

How is evolution of animal locomotion constrained?

Back 22

- Animals don’t always move in the most ‘efficient’ or ‘effective’ way because they must maintain the ability to do multiple things.