Lecture 10 Flashcards
T-shirt test: MHC and attraction
Men wore clean t-shirts for 2 nights. Intensity, pleasantness, and sexiness were rated. Women picked shirts from males with dissimilar MHC complex. Female is able to decipher from pheromones males that shared genes - not as attractive compared to males that had genes that were more different - more
attractive.
Major Histocompatibility Complex (MHC)
Most gene dense area of our genome, highly polymorphic, highly variable that presents your immune system response
Animal example of social pheromones
Maternal mouse pheromone - keeps pups close to their mother so they don’t wander away, close to mom and her milk supply
Social pheromones
Chemical signal that provides information - may or may not elicit a behavioral response
Animal example of primer pheromones
Bruce effect - when a pheromone in the urine of a male mouse who is new to the area may cause a pregnant mouse to abort or reabsorb her young
Primer pheromones
Influence an animal’s physiology once the pheromone has been received - may have a long term effect - chemical
Animal example of sexual pheromones
Boars have a pheromone in their breath that is attractive to females. If a female takes in this pheromone and is ready to mate, the female will go into “lordosis” and allow the mate to mount her.
Sexual pheromones
Deal with sexual attraction and elicits a response - ex: readiness to mate - chemical
VNO
Vomeronasal organ - receptors of pheromones
-found in reptiles, fish, rodents - area of sensitivity in upper palate, when pheronomes come in, those molecules hit the VNO and it is sensitive and connected to brain, and then identifies that pheromones are important. Olfactory sensitive area that many different animals have and used most often to secure mates - primarily
Role of exocrine glands
Pheromones are produced within the body from these glands through ducts (and communicate information between conspecifics, often go airborne or rest on substrate.
Pheromones
Substances that are endogenous (produced within the body from exocrine glands through ducts) and communicate information between conspecifics, often go airborne or rest on substrate. Taken in by an animal’s olfactory system.
Glucocordicoids
Allow animal to get body ready for challenge, stress response - more sugar in
blood - burst, muscles are moving (before you), appetite is suppressed, allow you
to meet challenge that is stressful, adaptive because it allows you to maneuver to
meet challenges to get what you need. Elk - get more food. At a high level, can hurt
your health - mice where high levels can kill them.
Relationship between prolactin and parental care
High prolactin levels reduces aggression - males are therefore hormonally primed to nurture - high prolactin = low testosterone (antagonists)
- T - sex hormone, prolactin is not. Found in both males and females. Males - an
antagonist - when male has surges of prolactin because partner is pregnant,
prolactin climbs to make him better caretaker, and testosterone goes down, so he
will not be a bully and be more careful.
Relationship between testosterone and parental care
Tradeoff where high T gets more copulations, but high T individuals are not as involved in parental care of offspring
Challenge hypothesis & testosterone
Theory that first came about studying birds, who are seasonal breeders -
testosterone is high in the spring and meet challenges, outside of the breeding
season they are less likely to challenge. Primates - chimps are vigilant with
high T all year, ready to go with aggression at any time.
