Animal Cognition Lecture Notes PDF

Animal cognition Claes Strannegård 20 January, 2025 Topics Origin of life Evolution Nervous systems Innate behavior Memory Origin of life https://www.youtube.com/watch?v=yTxZXkp-6sI Biosphere A 20 km thin layer near the surface of the Earth Living organisms...

Animal cognition Claes Strannegård 20 January, 2025 Topics Origin of life Evolution Nervous systems Innate behavior Memory Origin of life https://www.youtube.com/watch?v=yTxZXkp-6sI Biosphere A 20 km thin layer near the surface of the Earth Living organisms Organisms (animals, plants, funghi, bacteria, etc.) are able to reproduce (make more organisms of the same type) use building blocks from the environment The Hadean The Hadean is a geologic eon of Earth history preceding the Archean. It began with the formation of the Earth about 4.6 billion years ago and ended 4 billion years ago Early environments on Earth Temp variations due to night-and-day, season, location (e.g. water near hydrothermal vents) RNA world hypothesis https://www.youtube.com/watch?v=K1xnYFCZ9Yg Nucleotides in RNA Adenine Cytosine Uracil Guanine  Ribonucleic acid (RNA) is a molecule that is present in the majority of living organisms and viruses. RNA Strong backbone connections between any pair of nucleotides Unlike DNA, RNA is a single-stranded molecule Base pairing  In cold water with high concentration of nucleotides… Reproduction start  This happens Reproduction  Then, if the water is heated this happens… Reproduction  and then this Reproduction  If it is cooled again this happens… Reproduction  And when the water gets warm again… Reproduction end “Extraterrestrial life might be common” https://youtu.be/7yOiZLHDV3U?si=yZQbG83-ZEkhCFXR DNA DNA Deoxyribonucleic acid (DNA) is a macro molecule in the shape of a double helix, whose strands are united by pairs of nucleotides The star qualities of DNA It can reproduce (like RNA) It is a blueprint of proteins, which are the building blocks of life as we know it! It is a key ingredient needed for producing organisms What DNA looks like Sugar and phosphates at strands How DNA reproduces 1. Split a DNA molecule M into two halves 2. Add nucleotides 3. Two copies of M are produced! What genes are Genes are small parts of a DNA molecule (that encode a protein) Chromosomes A chromosome is a long DNA molecule with part of or all the genetic material of an organism. Where genes are located In humans the nuclei contain almost all genes (99.9%). The mitochondria contain the rest. Mitochondria generate ATP—the cell's main source of energy—via aerobic respiration, and as a result, they are known as the "power plants" of the cell. How proteins are produced in the body Explained in this 3-minute video or this video AI for protein structure prediction A distance matrix predicting AlphaFold predicts the 3D structure of proteins: the protein’s 3D shape A sequence of amino acids Transformer  For designing drugs, vaccines, sensors AI for protein design The input to Rosetta is a wish list on the desired 3D structure of a protein. The output is an amino acid sequence that folds into such a protein! Evolution https://www.youtube.com/watch?v=GhHOjC4oxh8 https://www.youtube.com/watch?v=0SCjhI86grU Origin of animal behavior: evolution Peppered moth Lived in London in early 1800s Blended in with tree bark and lichens Hard for birds to see Peppered moth Then came the industrial revolution Soot made the trees black Birds could see and eat them Peppered moths Exist in a black variety too About 2% of all peppered moths before the ind rev of this kind About 95% in 1895 The Galapagos finches A dozen of different finch populations (species) live here. All similar to a mainland variety. Different food is available on different islands… The Galapagos finches Lots of fruit here Lots of insects here Lots of seeds here The Galapagos finches Thick beaks for hard seeds Skinny and pointed beaks for insects Sharp beaks for puncturing fruits Properties of Properties of my genes myself Directional selection Directional selection is a type of natural selection in which one extreme phenotype is favored over both the other extreme and moderate phenotypes. Sexual selection Evolutionary theory Life on Earth is based on DNA Life evolves through selection, reproduction, mutation and death The selection factors determine which DNA is reproduced Darwin’s theory is supported by modern genetics Phylogenetic Tree of Life Why is it a tree?  Only those individual organisms that manage to reproduce in their environment pass their genes to the next generation (and are selected in the evolutionary process). To be able to reproduce they must survive at least up to the moment when they have reproduced. Thus, they need to have a combination of body and behavior that enable Animal behavior them to: Find, eat, and digest food (so that they can grow to maturity) Avoid dangers (so that they won’t die from For some species: find mate, be sexually selected, and raise young Evolutionary selection criteria on behavior: survival and reproduction Collaborate Handle competition Find mate Escape predators Help offspring Find food Break Nervous systems Model of a neuron Benefits of a nervous system Neurons form nervous systems Almost all animals have them Enable efficient Perception Locomotion Signal transmission Computation How neurons work Input signals in the form of positive and negative ions (Na+, K+, Ca2+, Cl– ) are received at the dendrites. Together the ions sum up to an action potential in the soma (cell body). If the action potential exceeds a threshold, the neuron fires and sends an electrical signal (spike) through the axon. The signal is transmitted to synapses that in turn send input signals to dendrites of other neurons, e.g. motor neurons. Nervous systems The 1 mm nematode C. elegans has 302 neurons Nervous systems Number of neurons: sponges: 0; bee: 1 million; zebrafish 10 million; raven: 1 billion; gorilla: 33 billion; human: 86 billion; elephant: 257 billion. Nervous systems Number of neurons in the brain: gorilla: 9 billion; human: 16 billion; long-finned pilot whale: 32 billion. Innate behavior Innate or learned behavior Some behaviors are innate (congenital), some are learned Innate behavior Two types of innate behaviors Reflexes Instincts Reflexes Reflexes are a motor or neural reaction to a specific stimulus in the environment. Examples the knee-jerk reflex the contraction of the pupil in bright light the grasp reflex the diving reflex goose bumps dogs shake water off wet fur Instincts Instincts are innate behaviors that involve locomotion of the whole organism. They could be triggered by aging and seasons. Examples Birds build nests Birds migrate as winter approaches Salmon swim upstream to spawn Spiders spin webs Instincts Newly hatched sea turtles will instinctively move toward the ocean Marsupials climb into their mother's pouch upon being born Honeybees communicate by dancing in the direction of a food source  Instincts An instinct to roll eggs triggered by a billiard ball Tinbergen noticed that gulls turn egg shells https://youtu.be/7PcteKRA3zs over so that the speckled side (not the white inside) faces up. Human instincts Fear of snakes and spiders was found in six-month-old babies Infant cry is a manifestation of instinct The herd instinct is found in human children and chimpanzee cubs Testosterone (main male sex hormone) primes several instincts, especially sexuality; also dominance, manifest in self-affirmation, the urge to win over rivals, to dominate a hierarchy, and to respond to violent signals in men, with weakening of empathy. Disgust is an instinct developed during evolution to protect the body and avoid infection by various diseases Taxis A taxis is the movement of an organism in response to a stimulus such as light (phototaxis) or the presence of food (chemotaxis). Taxes are innate behavioural responses. If the organism moves towards the stimulus the taxis is positive, while if it moves away the taxis is negative. Taxis is very common: "Virtually, every motile organism exhibits some type of chemotaxis." Examples are positive phototaxis in moths and negative phototaxis in silverfish and copepods. Phototaxis Positive and negative phototaxis in insects and in Braitenberg vehicles Chemotaxis Consider a bacterium with a head and a tail a smell sensor for sugar a smell memory reaching one step back Loop if smell got stronger: swim forward otherwise: make a random turn https://www.youtube.com/watch?v=yLAwDEfzqRw Kinesis Kinesis is the undirected movement in response to a stimulus, which can include orthokinesis (related to speed) or klinokinesis (related to turning). The purpose is to evade predators or quickly find more favorable conditions Decision-making Decision loop Repeat until you die Sense the environment Sense yourself Decide what to do Carry out the action Find food 4 actions Avoid predators Handle competition Survival game Pac-Man Survival game Minecraft (survival mode) Survival game Path-finding Find fastest route to peak Path-finding Find fastest route to peak Memory Memory Memory is today defined in psychology as the faculty of encoding, storing, and retrieving information (Squire, 2009). When memories are formed, the brain changes physically The brain has structural plasticity Emotional memories last longer Good memories: first kiss Bad memories: when someone died What is the point of remembering things? Memories of the past help us predict the future Things tend to be the same, event sequences tend to repeat If the world were random, memories would be useless The future resembles the past “The supposition that the future resembles the past, is not founded on arguments of any kind, but is derived entirely from habit.” — David Hume The sun goes up every morning habit = experience Winters are cold Wolves eat sheep Ice is slippery Brains are prediction machines If we can predict well, we can make better decisions https://neurosciencenews.com/prediction-brain-21183 The point of long-term memory I predict that there will be fish here (because I remember they were there in the past) I predict that there might be predators there (because I remember they were there in the past) I predict that this berry is good to eat (because I remember such berries were good to eat in the past) I predict that this berry is bad to eat (because I remember such berries were bad to eat in the past) The point of short-term memory Can determine if smells, sounds, etc. increase or decrease Can remember where you have been To get back to a place (with food and without dangers) To avoid getting back to a place (with no food or with dangers)  Memory can make a difference between life and death The point of memory formation These Weddell seals need to remember the location of the breathing hole when they hunt for fish under the ice