Segment 10 Illustrative Examples Part 3

3.E.1 Individuals can act on information and communicate it to others c. Responses to information and communication of information are vital to natural selection and evolution. 1. Natural selection favors innate and learned behaviors that increase survival and reproductive fitness. Illustrative example: • Parent and offspring interactions (834) • Migration patterns (825) • Courtship and mating behaviors (831-833) • Foraging in bees and other animals (830- 831) • Avoidance behavior to electric fences, poisons, or traps 2. Cooperative behavior tends to increase the fitness of the individual and the survival of the population. • Pack behavior in animals (833) • Herd, flock, and schooling behavior in animals (834) • Predator warning (828) • Colony and swarming behavior in insects (833)  

Migration Patterns (P. 825) Migration requires Orientation: ability to travel in a particular direction (ex: birds use the sun or stars to orient themselves) Experienced birds can Navigate: ability to change direction in response to environmental clues (these clues come from the Earth's magnetic field) Migration continues although it's dangerous due to the benefits exceeding the cost  Reaching the more favorable environment for survival and reproduction is worth the dangers of travel

Timing of Courtship Egg production is controlled by hormones and creates cyclical estrous cycles When a female has an egg available to be fertilized she is in “estrus” There are different lengths of estrus cycles: dogs (twice a year), bears (once a year), rabbits (always) Humans and apes have a hormonal menstrual cycle in place of an estrous cycle Their eggs are still controlled by hormones Key difference is if there is no fertilization they shed their uterine lining involuntarily instead of like other placental mammals that reabsorb it Many other animals like fish reproduce based on the timing of their environments like the temperature of the water

Hormones Most animals are signaled to sexually reproduce through hormones When females ovulate, the sex glands release the hormone estrogen into the blood stream Pheromones are chemicals secreted by species to communicate to others of the same species These are especially important in lower animals like cockroaches In mammals, it’s also important to attract a mate from long distances like a deer rubbing its leg against a tree or a female dog urinating Certain studies with mice have found that females stop having regular sex cycles when there are no male odors present. Once there are, their cycles synch up again.

Frequency Semelparity is when species only reproduce once in their lifetime and then die since all of their energy goes towards making gametes Iteroparity is when species reproduce more than once in their lifetime Species can be monogamous and only have one mate in their lifetime or one mate in their breeding season Polygamous species have more than one mate

Courtship Rituals Sexual dimorphisms are the differences between males and females that evolved because of the differences between the two in courtship Giraffes lower their necks (rare) to sniff other giraffe’s urine to see if it is in estrus Intersexual selection is when the decision to reproduce is based on the interactions between males and females The females are usually the one with the power of choice since their gametes are limited and take a lot of energy Peahens chose peacocks with elaborate feathers Some birds collect seashells to build nests Intrasexual selection is when members of the same sex battle for rights over the entire group Males will fight other males and the winner gets to reproduce with the whole group Elephant seals due this and get rights to the whole beach of female elephant seals