Lecture 13 Animal form + Function

What does the word anatomy mean?

Structure of a organism. (Shape and size.)

What does the word physiology mean?

Function. How the anatomy works to support life.

What does the word interconnected mean in biology?

Evolve together. Changes in structure influences function.

What is a trade off?

Gaining an advantage in one area leads to disadvantage in another.

Why do trade offs occur?

• Limited energy

• Balance growth + survival

What are the key areas of energy allocation (spending energy)?

• Growth (developing size)

• reproduction (producing offspring)

• Immune function (fighting off illness)

• survival (movement)

How do adaptations arise?

• climate pressures, predators, food sources.

Adaptation vs Acclimatization

Adapt: Long term, driven by natural selection, genetic.

Accli: Short term, reversible, response to environmental conditions, non genetic.

Types of constraints in adaptation:

• genetic

• developmental

• historical

Large Vs small animals

L: Low metabolic rate, stores heat, Lower SA:V, overheating

S: High metabolic rate, loses heat fast, Higher SA:V, more food + water to survive.

SA:V what is the point:

affects essential functions such as heat loss and gas exchange.

How to beat diffusion limits?

• Flattened structures (flatworms absorb oxygen through skin)

• Hollow body plans (Jelly fish reduce volume)

• specialized organs (Gills + Lungs increase sa)

Bergmans rule:

Larger animals are found in colder climates bc they have lower SA:V helping to retain more heat.

Allens rules:

Animals in hot climates tend to have longer limbs which increases sa and helps to dissipate heat.

Why cant we have giant insects?

Because diffusion become insufficient and they would struggle to get enough oxygen to support their larger bodies.

What is homeostasis?

Process of maintaining stable internal environment despite changes in external.

components of negative feedback in homeostasis

• sensor: detects changes in internal conditions (temp in body and brain)

• Integrator: compares detected value to set point

• Effector: acts to correct deviation from set point.

Endotherms:

• Mammals and birds

• regulate body temp inernally

Ectotherms:

• depend of external sources for heat

• reptiles amphibians

Trade offs of ecto and endo

ENDO advantage constant activity regardless of conditions cons demands high metabolic rate

ECTO: saves energy by not needing to generate heat internally, cost slow/inactive in cold conditions

Heat transfer how animals stay cool or warm:

Conduction: heat transfers when 2 objects are near eachother heat moves from warmer to cooler areas. Lizard basking on a rock rock warms its body.

Convection: heat transfered via movement of fluids aka air and water.

evaporation: cooling down by sweating