Lectures M1-M2 Flashcards
(232 cards)
Hamilton relatedness
rB > C
relatedness, benefit, cost
Naked mole rats relatedness and eusociality
- Queen female gives birth to all
- Only mammal that shows eusociality
- Communal care of young
- Reproductive division of labour
- Overlapping generations
Why?
High genetic relatedness
0.81 relatedness
More than any other non-inbred species
Should one kill its sibling - sibling-offspring conflict
Look at rb>c
r=1 for itself, r=0.5 for its sibling (if same father)
- So yes they should fight to survive and kill if need be
- Might also kill them bc it would allow them a better chance of making it to a high weight
How much should a parent invest in their offspring = parent-offspring conflict
- depends on life time cost and benefit
- Consider effect on future offspring and future ability to reproduce
- Offspring may seek more than parents should provide (need to save energy for next offspring) → conflict
Phylogeny
- All living species are a product of descent with modifications from common ancestors
- More related if branch at the same place (same common ancestor)
- More recently related if branched later (closer to the branch tips)
Primates groups (phylogeny)
Primates
- Tarsii
Strepsirrhini
- Platyrrhini
- Catarrhini
Catarrhini
- Cercopithecidae
- Hylobatidae
- Hominidae
Hominidae
- Pongo
- Gorilla
- Pan
- Ardipithecus
- Australopithecus
- Homo
Origins of agriculture - humans
+ definition
Agriculture = planting of certain cultivars in particular substrates
- 10 000 ya in humans
- Cultivation aimed at improving crop growth for food
Insect agriculture
- 50/66 million + years ago in ants and beetles
- involves growing fungi on gardening substrate (e.g. plant material) and protecting their crop from undesired species (weeds and pests)
- use pesticides
- Nine independent origins of insect agriculture, all involving fungal crop
- No reversal to non-agriculture life
1 origin in ants, 2 in termites
Giant asteroid 66 mya
- Caused global mass extinctions and shut down photosynthesis for several months
- Fungi proliferated as they feed on decaying organic matter
- Underground species survived better
- Opportunity for mammals to evolve
Microns and more (measurements)
+ what can we see
1 mm = 10^-3 m
1 micron = 10^-6 m
1 nm = 10^-9 m
- with the naked eye can see down to 0.1 mm
- bacteria and cells 1-30 microns
- viruses 20-100 nm
Learning
- Learning is the ability to acquire a neuronal representation of new information
- An individual may use that information to determine subsequent behaviour
Chemotaxis
- The ability of organisms and cells to move up or down chemical gradients
- Bacteria flows from high to low concentration areas
Chemotaxis in bacteria
- Even organisms with no nervous system modify their behaviour based on experience
- Successive comparison, (better or the same) which requires a minimum of one-step ‘memory’
- Bacteria can only keep the same direction or tumble to randomly change direction
- Simultaneous comparison is impossible because the chemical gradient across the body is too small
Humans chemotaxis gradient
- Do use simultaneous comparison for hearing and seeing, done by nervous system
Simultaneous comparison in humans
Do use simultaneous comparison for hearing and seeing, done by nervous system
Chemotaxis in E. coli
- Detection by receptors
- Conduction by messenger
- Processing based on messenger concentration (‘polling’)
- Transmission of decision
- Response
- flagella direct movement
NOT learning but similar
Sydney Brenner - C. elegans
- A small soil worm (1 mm) that feeds on bacteria, with ~959 cells and 302 neurons, with all synapses mapped & entirely sequenced genome
- Researchers can turn off individual neurons by laser ablation & record from individual neurons
Biomimicry
Copying successful mechanisms of animal behaviour into new gadgets
Innate behaviour
A behavioral pattern that appears in fully functional form from the first time it is performed
(the animal may have not had prior experience with the cues that elicit that behaviour)
- Similar terms: instinct, fixed action pattern, motor program
Example: fly courtship, nest building, blinking
Innate behaviour - advantages
- Saving time when responding to stimuli
- Proper response the first time = making less mistakes
Ex. Village weaverbird
Male chooses a forked branch and builds nest around itself in a specific shape
Goose video
Innate eggs
- All round shaped things=eggs
- Ensures no real eggs are left behind
- Roll any thing near nest and slightly egg like (don’t have to be the right size or shape though)
- Instinct to recover eggs rolled from nest
- Greater benefit to saving all potential eggs than cost of caring for one extra egg
Damselfly experiment
Question: Can damselfly larvae show anti-predatory behaviour to an unknown predator?
- Use damselflies never before exposed to pike (predatory fish), evolved in a habitat with no pike and are inexperienced with pike in the laboratory.
- Let 3 groups of pikes feed on minnows (small fish), damselflies (of the same species) or mealworms (beetle larvae)
Note: minnows co-occur in nature with the damselflies but beetles do not - Move the pikes to different tanks with fresh water and keep them there for 3 days
Damselfly experiment - results
- Damselflies more scared behaviour in tanks with potential predators (reduced activity)
- When they smelled pike + dead damselflies
- Or pike + dead minnows
- NOT pike + mealworms (not familiar with either)
Avoid smell of dead FAMILIAR animals
No innate fear response to unfamiliar ones
NO innate antipredatory response to pike
YES innate antipredatory response to unknown fish that has preyed on damselflies or minnows
NO innate response to unknown fish preying on unknown prey
Insects and blood preferences - background
how many ppl does it infect
- subspecies Ae aegypti that is brown and gets meals from humans = domestic species
- infects 400 million ppl / year
- spreads dengue fever, etc.
- accidentally introduced into Kenya in 1950s
- they would lay eggs in water containers