Chapter 6 Flashcards
Honeybees
- Bees need to build a huge population, build comb, collect nectar.
- Scout bees find rich sources of nectar and pollen and communicate where this is through the waggle dance.
- Communicate exact distance and direction, amount of food and quality of food.
What is the algorithm?
Waggle dance
Body movements give a signal of where the other bees should head out towards the food source
Vervet Monkeys
Lots of predators in the air, ground, eye level and below line of sight.
Robert Seyfarth (Psychology Professor):
Can monkeys talk?
We thought vocalizations were involuntary sounds.
Vervets live in groups of 20s and were thought of given predator alarm calls to other monkeys.
Different alarm calls for different predators that elicited different responses.
Is this language?
Alarm calls are generalized alerting devices.
Leopard call = climb up in tree
Snake call = stand on hind legs
First evidence of how you might have language (or kinda like a word) in a non human animal.
→ Have a very developed cerebral cortex, as they got more complex, the signaling sequences change. Become short and specific auditory sequences → specific sounds for the predator
Koko the Gorilla
Koko the gorilla could learn human sign language to communicate;
Once you have complexity of different parts of the brain that understands symbols.
Cortex of the brain allows for complex cognitions - understanding of words or phrases that are unfamiliar to us.
Monkeys are the use of words to communicate communication, but when you have more complex brain structures you can have sign language.
Short sentences
Sensory receptors
Nerve endings that respond to an internal or external environmental stimulus
Chemoreceptors
Detect chemical stimuli
- ->Gustation: Detection of dissolved chemicals through taste
- ->Olfaction: Sense of smell
Pheromones
Volatile (gaseous) compounds that are species-specific and affect the behaviour of another individual of the same species
Volatile means that it can be airborne or gas borne.
Released from one organism and has an impact on another impact of the same species since they share the same receptors.
Pheromones are volatile AND nonvolatile substances
Are pheromones (chemicals) only airborne? NO → it is volatile and nonvolatile compounds that can have an effect on the recipient
The Bruce Effect
Disruption in implantation due to presence of a novel male.
There is a pheromonal communication that leads to disruption in pregnancy in females
The novel male will kill any of the newborn in the territory that he wants because it is a waste for him to raise the other young. This makes the female become available to be mated with
Observed in mice and rats → simply the presence of a novel male in the environment of a recently pregnant female will lead to terminated. Does Not have to do with physical contact, he thought it must be pheromonal
Disrupts the early part of pregnancy → implantation
Vandenbergh Effect
Decrease in time to sexual maturity due to presence of a novel male.
If a novel male is around, it will influence the females to become sexual maturity quicker. Does not need direct contact, therefore must be pheromones
The Bruce Effect Continued- Hormones involved
What exactly is the male releasing? What are these chemical
Both males and females produce hormones (both produces estrogen and testosterone)
Pheromones can be any chemical as long as it has an effect on the recipient
Pregnancy hormones are very important, can have a physiological impact on the maintenance of pregnancy
Test the urine of male (males spray urine towards the female he is interested in)
Two important hormones in male urine: 17β-estradiol (estrogen) & testosterone in male urine (Muir et al., 2001)
During pregnancy there is estrogen and testosterone made in a female, but the balance of this is extremely important
Castrated males (remove testes where sperm is produced) lose ability to disrupt pregnancy, unless given 17β-estradiol (deCatanzaro et al., 1995)
Castrated males can no longer induce the bruce effect
If you give the castrated male injections of estrogen, it restores his ability to disrupt implantation
Females given 17β-estradiol antibodies retain their pregnancy (deCatanzaro et al., 1994)
Antibody has the capability to bind to estrogen and keep it from having an effect
This causes the Bruce effect to not work
Males are increasing the estrogen by peeing on her, its absorbed via skin. When the exogenous estrogen increases, it impacts her ability to maintain the pregnancy.
When aromatase inhibitor is administered to an intact male, lose ability to disrupt pregnancy (Beaton & deCatanzaro, 2005)
Aromatase is the enzyme responsible for producing estrogen in the system
The medication inhibits aromatase which inhibits the production of estrogen and this causes the male to lose his ability to disrupt pregnancy
Hormones are behaving like pheromones.
The hormones are carried in a vector because they are not volatile, they use the urine as a vector
What happens if you give females aromatase inhibitors?
GRAPH
Does giving females aromatase inhibitors cause her to lose her pregnancy?
They were given exogenous estrogen intra-nasally
Take micrograms of estrogen and expose them to the recently pregnant females and observer who is giving birth. At .29 microgram, you start to eliminate pregnancy
At 0.8, you are eliminating a lot of pregnancies
Indirect Exposure Paradigm
GRAPH
How to you expose males to a developing females without contact.
Cage double decker and at the top the makes were houses with a female at the bottom.
Males have a brown coat is researchers used a strain that has a bunch of different genetic heritability.
Taking males and females from a lot of different personalities types. This leads to variability which leads to a hardy animal, genetic expression is really varied. You can see this by looking at the fur coat
Brown coat is very interested in females and interested in mating (stud)
Not a lot of genetic variability in the white female
Used 2 males to increase urine exposure to females
What happens if you have hardy male (with lots of genetic variability) exposed to a female vs. if he is just sitting alone, does the steroid output change.
On average the amount of estrogen released when males are exposed to developing females is higher than the males that were seperated.
Overall clear difference between males that are near the developing females vs. those in isolation
Ovaries and Uterus change size
GRAPH
The uterus and ovaries increase in mass when females reach sexual maturity, so does the female’s body mass
The uterus and ovarian and body mass is much less than those exposed to males
Ovaries may not be the best indicator because they change size during your period cycle
Uterus is a good indicator
Shows that pheromones do not have to be volatile
This also showed that the pheromone is actually a hormone, when it is released, it acts like a pheromone because it is impacting others
CSF1 and HS can be ignored it is just the strain
Signals can Accurately indicate Signaller Phenotype and Environmental Conditions
- an honest signal is….
- Fitness interests of signaler and receiver are similar
- Signals will be accurate when they cannot be faked
- Signals will be accurate indicators when they are costly to produce or maintain
1.Fitness interests of signaler and receiver are similar. Fitness of the predator and the prey are similar
Coral snake, frog, caterpillar → poisonous
Bright colour indicates that I am poisonous, stay away from me
Tells their pray to be sacred, tells other predators that i am poisonous
Aposematic Colouration: the bright colouration is a signal to toxicity
Fitness interest of the signaller and receiver are similar, it is survivorship → don’t eat me or you will die, increases survivorship of predator and prey
- Signals will be accurate when they cannot be faked
Only LARGE animals produce LOW volatilization
Clear signal and it can be used as a way to asses
The frequency of the sound is dependant on the size of the male
The auditory signals allows other rivals males to make an estimate of the other males in the environment
