Animal Form and Function

Question 1

Limits and tradeoffs

Plasticity within certain limits

Answer 1

the ability for a trait to change based on environmental conditions

Question 2

Plasticity

Frog Example

Answer 2

• Amphibians grow throughout their entire lives
• the rate at which they grow is dependent on multiple factors such as resource availability and space
• but
• even with infinite resources and time, there is a limit to how big they can grow due to a genetically pre-determined limit of supportive structures in their body plan

Question 3

Selective pressure compromise

Answer 3

• there is never only one pressure at a time.
• In order to adapt to one, you often must sacrifice ability to adapt to another

Question 4

selective pressure compromise

Giraffe example

Answer 4

• Giraffes adapted to have long necks to reach previously unaccessable food, avoid predation, and for males to fight over females
• comes with a tradeoff
• specialized vein systems necessary to keep them alive when they drink
• extremely vulnerable when drinking, making them more susceptable to predation

Question 5

Environmental Variability

Answer 5

• different environments demand different loadouts of adaptations
• Ex: animal can’t master terrestrial life without compromising aquatic life
• Hippo cannot swim as well as a whale, but has much more versatility on land

Question 6

Becoming larger

Answer 6

• to escape predation or increase competitive edge against other species
• requires multicellularity, cell specialization, organ systems for transporting nutrients, water, energy sources, and waste products between outer and inner environments of the organism

Question 7

Obtaining Energy

Generalist

Answer 7

• Jack of all trades, master of none
• Corvid Example
• opportunistic omnivores, can eat fruits, insects, human garbage
• because of this, they can be found in most habitats around the world except south america
• however, in constant competition with other animals, who are usually better adapted at getting the specific food item than they are
• able to survive due to abundance of options

Question 8

Obtaining Energy

Specialist

Answer 8

• well suited for one strategy only
• hummingbird example
• live in very few, specific habitats
• have unique feature that gives them decisive advantage at one specific thing
• specific bill that mirrors the shape of specific flower, allowing them to not have to compete with other animals for access to that resource

Question 9

Energy source variability

Answer 9

• different energy sources require different adaptations to access them
• Ex: plants adapted chloroplasts to gain access to solar energy, whereas animals have adapted to eat other organisms. no animal can photosynthesize, and no plant can eat other organisms
• lions cant digest grass, cows cant digest meat
• carnivores, herbivores, omnivores

digestive systems of carnivores are simpler than those of herbivores

Question 10

Energy Storage

Dromedary Camels

Answer 10

• large animals in environment where energy is scarce
• adapted humps to store fat
• thick piss to not waste water

Question 11

Storing Energy

Endothermy

Answer 11

• Warm blood
• higher energy lifestyle
• even those who hibernate must awaken to dump waste (lol) and restock energy supplies
• more complex lungs for greater oxygen use
• more complex cardiovascular system

Question 12

Storing Energy

Ectothermy

Answer 12

• Cold blood
• low energy lifestyle
• less complex respiratory system
• less complex cardiovascular system

Question 13

Respiratory System

Answer 13

Brings in Oxygen, releases carbon dioxide

Question 14

Cardiovascular system

Answer 14

transports nutrients, wastes, and gases throughout the body

Question 15

Energy Use

Answer 15

• Once energy is stored, organisms must decide how, when, and why to use it
• Examples:
• some animals travel a lot, some barely move
• some put lots of energy into getting large, some barely grow
• some create expensive ornaments for sexual selection, some stay plain

Question 16

energy use

Octopus Example

high energy use

Answer 16

• live fast die young bad girls do it well
• longest lived octopus is giant pacific octopus with a lifespan of only 3-5 years
• in that time, they can reach up to 33 pounds and develop inteligence and problem solving skills on par with primates
• can also use chromatophores in skin to completely control physical appearance to master camouflage and attract mates
• breed once only before dying
• all these things are energy intensive and must be done in a short time, so they are using energy constantly

Question 17

energy use

Tortoise Example

low energy use

Answer 17

• among longest living species on the planet, regularly reaching over 100 years old
• takes 40 to 50 years to reach full size
• spend most energy on growing super thick shell

Question 18

Seasonal Environments

how different animals adapt to the same problem of winter

Answer 18

• 3 different species deal with winter differently
• Woodchucks dig burrows and hibernate, allowing their body temperature to decrease drastically so they dont have to forage for food
• Arctic Terns spend half year in arctic north pole, half in antarctic south pole, they migrate to wherever it isnt winter
• Coyotes grow extra thick fur, and prey on small mammals and birds who are struggling through the cold

Question 19

Surface Area to Volume Ratio

Answer 19

• As organisms get larger, the proportion of surface area to their internal volume gets smaller
• can evolve to be flat (like amoebas and flatworms) but comes at the cost of increased distance between organs causing resource distribution issues
• changes caused by this
• heat loss rate decreases
• dehydration rate decreses
• number of predators decreases
• number of shelter options decreses, but need for shelter decreases
• absolute amount of food and water needed increases (greater surface area means more heat energy and moisture lost, so must consumer more energy)\
• with ectotherms, problem is mainly smaller organisms (young) have very high surface area to volume ratio and dry out quickly

Question 20

Predator Avoidance

Answer 20

1. being unappealing to predators
2. being hard to find
3. running away

Question 21

predator avoidance

being unappealing to predators

Answer 21

1. being larger means there are a smaller number of other animals that can kill you (may also be acomplished by being armored)
2. Unpalatable: unpleasant taste, nausea inducing, or poisonous. Often have Aposematic bright coloration to indicate this to predators, and some use Mullerian mimicry (resemble other unpalatable species to reinforce indicator)
3. Species that are not unpalatable can use Batesian mimicry (mimicing an unpalatable organism) to decieve predators into thinking theyre unpalatable when theyre actually just normal

Question 22

predator avoidance

Being Hard to Find

Answer 22

1. becoming Cryptic (Camouflaged) reducing their chances of detection
2. being quiet (ex. when toadfish hear dolphins foraging noises, they reduce their call rate by 50% for about 5 minutes)

Question 23

predator avoidance

Running Away

Answer 23

• Flight initiation distance: how close a predator can approach before prey flees
• effected by the following factors
• Prey condition: body size, reproductive state, sex, age, temperature, group size, crypsis, hunger, morphological defenses
• Predator condition: speed, size, directness of attack, predator type, starting distance, number of predators, predator intent
• Refuge: distance to refuge, light, time of day, habitat type, patch quality

Question 24

Reproduction

Answer 24

Finding a mate tends to require a form of signaling, which in addition to indicating an animals availability, may also indicate their quality as a mate

Question 25

reproduction

visual signaling

Answer 25

male bowerbirds build a structure to attract females, decorated with sticks and bright color objects. objects sometimes have a theme such as a single color

Question 26

reproduction

auditory signaling

Answer 26

birdsongs, male songbirds often have many differnt songs, and the amount of songs they can sing is correlated with mating success

Question 27

reproduction

chemical signaling

Answer 27

pheromones are released into the environment. ex: silk moths can detect pheromones with their antennae and use them to find females

Question 28

reproduction

tactile signaling

Answer 28

water striders produce ripples on the surface of the water in different paterns, specific signals for calling mates, courtship, copulation, and postcopulation

Question 29

reproduction

mating systems

Answer 29

• Monogomous: one male one female, in species where finding mate is very difficult
• polygamous: one male multiple females
• polyandrous: one female multiple males

Question 30

reproduction

Maximizing reproductive success

Answer 30

• animals are evolved to maximize reproductive success
• tradeoff of quantity vs quality
• organisms that devote a great deal of energy to producing large quantities of offspring have less energy available to dedicate to each individual offspring and to their own survival (ex. immuine system, growth)

Question 31

maxing reproductive success

Red-Tailed Hawk example

Answer 31

• Red tailed hawks lay two eggs but at different times, resulting in one being born before the other and therefore being larger
• when food is low, the larger offspring will claim it all and leave the smaller one to die
• when food is plentiful, there will be enough for both to survive
• allows for the potential to have two offspring rather than just one depending on variability of food abundance, even though it wastes some resoures producing the second egg
• imperfect, but advantageous