Midterm 2

Social dispersal reduces the occurrence of inbreeding; ex: Cheetahs and white-footed mice

In birds, it is typical for the males to remain in their natal territory and maintain a "territory" in which they will try to attract female mates via song. In mammals, it is typical for the females to remain in their native location so that they can take advantage of relatives as aids to help raise the offspring and to take advantage of known resources in the area. Male mammals typically disperse in an attempt to find mates.

There is a genetic component in butterflies that enables some to more easily disperse and be successful in some place other than their natal area. The butterflies that have the genetics that allow them to be more successful when dispersing are often more efficient at flying and reproduce quicker than butterflies that are philopatric.

Yes, biological clocks will run in the absence of environmental cues.

When the SCN region of the chipmunks' brains were ablated, the chipmunks lost their biological rhythms and were very susceptible to predation

Cranes learn their migration patterns by learning from their elder relatives. Because a monarch's lifespan is so short, it often takes up to three or four generations for a monarch to reach a season in which they migrate. This shows that a monarch's ability to know where they migrate has a genetic component

Biological clocks: Cycles continue in the absence of environmental cues such as light or darkness and temperature cycles; the biological clock must be reset in order to maintain synchrony

-Following food that is also migrating

They are important in hibernation, dispersal and migration. 

1. Chemical Olfaction; 2. Sound- Echolocation; 3. Electrical; 4. Visual cues; 5. Magnetic cues: (Ex. Iron containing structures in the beaks of homing pigeons help them find their way)

1. Frogs and lizards have long, sticky tongues

Leaf-cutter ants will gather leaves to grow fungus on to feed to their young; they cultivate the fungus much like farmers cultivating land

-Dolphins use sea sponges to protect their snouts when they forage among sharp sea grasses

-Whales create bubble nets in order to gather a concentration of krill to consume

Aggressive mimicry is when an animal mimics something in order to lure in potential prey.

By using a search image - the predator looks for characteristics to associate with their prey and scans for those when hunting.

Predator looks for characteristics to associate with their prey and scans for those when hunting. It is more efficient to form associations when hunting for prey vs. no search image.

Weighing costs and benefits of the foraging behavior. Ex. getting the most nutrients for the least amount of effort

-Food caloric value

-Oystercatchers will select a medium sized oysters rather than a large or small oyster. Larger oysters represent too much of a cost because of the energy spent to crack open the oyster is not balanced with the benefits

As predators develop adaptations to find or catch prey, the prey develop adaptations which allow them to survive from the predators. Predators that have characteristics which allow them to get around a prey's defense have a higher survival rate, and vice versa with prey-to-predator

Some newts are extremely toxic and produce a toxin which can poison predators willing to attack it. Garter snakes are able to consume the newts without feeling the effect of the toxin, due to adaptation. In turn, the newts are required to create a stronger toxin in order to maintain a high survival rate.

Ex. Wallabies need to be trained to detect odors of predators and be made aware of danger; humans have found that if they use operant conditioning to train the wallabies to avoid a certain smell, there is a greater chance of evading potential predators 

Ex. Jumper ants use their jaws to quickly flick themselves into the air to escape predators

A harmful species mimicking another harmful species

Harmless species mimicking a harmful species

Applying the scent of another animal to cover one's own scent

It breaks up the outline of an animal, making it difficult to distinguish

Alternating dark and light colors to effectively camouflage oneself visually

When the environment changes with the seasons, so do the colors displayed by animals

Leaf bugs and walking sticks; leafy sea dragons appear to resemble seaweed in the ocean; certain types of insects will look unattractive to predators by looking like bird droppings

Possessing a color scheme that warns animals that the species is harmful

-Lizards: tail autonomy

-Puffing out fur

Deer use antlers; other animals might use claws or fangs to defend themselves; Skunks produce an odor to ward off predators

Time and energy is saved by not having to find a mate

-No variation, so therefore no evolution

Variation, which leads to evolution and survival of a species over time

-Time and energy is exerted to find/impress a mate

1. Whiptail lizards (are all female)

Without two parents involved, there would only be one set of chromosomes that would be cloning itself (therefore no variation) -- Having chromosomes from two parents allows for variation with thus allows for evolution

Meiosis (sperm and egg)

It combines two sets of parents' chromosomes to make one set of chromosomes for their offspring (variation)

The asexual minnows were much more prone to parasites and black spot disease. The sexual minnows had lower incidence of disease due to variation. When a drought occurred, the population was so reduced in numbers that inbreeding occurred in the sexual minnows which reduced variation. This population became more disease infested

Unless a species continues to evolve and change throughout time, it will undoubtedly not survive

Males and females look different from one another - males usually are more ornate for mating purposes

1. Competition to secure mates

-Dominance contest (red deer)

-Mate guarding

Females choose males based on:

Females cannot reproduce as often as males and have a limited supply of eggs to fertilize into offspring. They desire stronger males who can in return provide greater success for their offspring.

Size, ornament, color, song repertoire, parental care behavior (courtship feeding), construction (bowerbirds)

Petrie's experiment with peacocks in which the males with more elaborate tails attract females and have less parasites and more viable offspring; zebra finches songs - the more complex the songs, the better learning skills they possess which are beneficial to raising offspring

If the tail is clean and well groomed, it advertises fitness to females. The number of eye spots also indicates the health of the peacock by indicating if the peacock possesses any diseases

A female will typically consume the male in order to provide sustenance for offspring shortly after birth

By eating the male the female is providing her eggs with lots of good nutrients ensuring her offspring a more successful life both in survival and reproductive success