L12 - Proximate mechanisms Flashcards
What are proximate mechanisms?
Immediate causes or mechanisms that directly contribute to a particular behaviour or trait. It considers how an organism performs a certain behaviour or trait in terms of both physiological (internal) and immediate environmental (external) factors.
What are Ultimate mechanisms?
Explains or relates to the evolutionary forces that directly contribute to a behaviour or trait.
What is Fregata minor?
Great Frigate birds
What are proximate mechanism - hormones in mammals? Pineal gland?
Melatonin, many targets, bio clock.
What are proximate mechanism - hormones in mammals? Pituitary gland?
FSH, LH, ADH, Growth hormone, oxytocin, prolactin. Ovaries, kidneys, uterus, breast tissue, many others. Menstrual cycle, osmoregulation, growth & division, birth contractions, milk production.
What are proximate mechanism - hormones in mammals? Thyroid gland?
Thyroxin, liver, metabolic rate
What are proximate mechanism - hormones in mammals? Adrenal glands?
Adrenaline, cortisol, many targets, fight or flight, anti-stress.
What are proximate mechanism - hormones in mammals? Pancreas?
Insulin, glucagon, liver, blood sugar levels.
What are proximate mechanism - hormones in mammals? Ovaries?
Estrogen, progesterone, uterus, menstrual cycle.
What are proximate mechanism - hormones in mammals? Testes?
Testosterone, many targets, male characteristics
What are proximate mechanism - Aggressive interactions?
From fish to mammals, testerone levels correlate with aggression levels. Castration has been found to reduce aggression dramatically, while experimental reinstatement of testosterone restores aggression.
What can hormones act as?
Behavioural primers, testosterone - prime for aggressive encounters with competitive males. Behavioural feedback loop.
How are hormones primers in Baboons?
In chacma baboons in Botswana, Testosterone was predictive of a male’s future rank and predictive future, rather than current, mating activity.
How can proximate mechanisms hormones be measured in Chacma baboons?
Simultaneous investigation of urinary and faecal glucocorticoid metabolite concentrations reveals short-versus long-term drivers of HPA-axis activity in a wild primate (Papio ursinus). Low cost, non invasive. A seasonal decline in faecal GCs from winter to summer, linked to warmer Ts, lower rainfall, and increased day length.
What stimulates hormone release?
Brain is in control of hormone secretion, transport protein is in control of hormone transport. Target cell is in control of response to hormone
What can stimulate hormone release - example?
Temperature and day length
What hormone stimulates moulting in birds?
Moult is controlled by release gonadotropin and thyroxine. Thyroxine stimulates the feather follicle and growth of the feather. Oestrogen inhibit the moult, progesterone suppresses ovulation and induces a concurrent moult of the feathers.
What hormone are stimulated Red deer, Cervus elaphus?
November-August, small soft velvet antlers hierarchical groups. September-October, large antlers, M-M comp, harem formation. Increased androgens, changing enviro
How is perception of stimuli changed by hormones?
Sticklebacks attacked the sides of the aquarium when a red mail van passed beside the window of the aquarium. Tinbergen designed models of sticklebacks, painted them various colours, including red, and presented them to the male sticklebacks in the tank. Red coloured models always elicited more reaction from courting males, demonstrating that it was the colour red (rather than the shape/identity of the fish) that acted as the ‘releaser’ for a specific action from the male
What are sensory neurons?
Are the nerve cells that are activated by sensory input from the enviro. E.g. when you touch a hot surface with your fingertips, the sensory neurons will be the ones firing and sending off signals to the rest of the nervous system about the info they have received
What can the inputs that activate sensory neurons be?
Physical or chemical, corresponding to all five of our senses
Neurons - What are dendrites?
Part of the neuron which branch off. They are sticky looking things in where impulses are created.
Neurons - What are axon?
Once these impulses are created, they travel down the axon. The axon is the stem like part of a neuron in where the end is.
Neurons - What is a synapse?
A connection from one neuron to another.
Label a Neuron?
Telodendria, synaptic terminals, axon, axon hillock, cell body, golgi, nucleus, ER, mitochondrion, dendrite, dendritic branches.
How does info travel in neurotransmitters?
Info travels from sensory receptors to the brain or spinal cord via neurotransmitters (glutamate is the most common neurotransmitter). Approximately 10 million sensory neurons exist in the human body.
What are the chemical senses?
Taste and smell
What are the Mechanical senses?
Touch, pressure, vibration, sound
What are the electromagnetic senses?
Sight
Chemical senses detected - in insects?
Detect chemicals in water and food (gustation), the air (olfaction). In insects: neurons located on sensory hairs on proboscis, legs, feet and antenna
Chemical senses detected - in vertebrates?
Detect chemicals in water and food (gustation), the air (olfaction). Sensitivity in differs greatly (mammals>birds>reptiles>amphibians) and for olfactory receptors, humans ranging from 5 million but dogs have 220 million
What is the olfactory bulb used in?
chemical sense for geese and corvids
What is an example of mechanical sense - sound?
Jackdaws on singleton campus, bats and dolphins hear higher freq, dogs and elephants lower freq. Humans and cats middle
What is an example of mechanical sense - touch, pressure?
Star-nosed mole, Condylura cristata
