B3 Topic 2

Monogamous - just have one mate for life. e.g. swans, puffins, coyotes and jackals.

Polygamous - have more than one mate in their lifetime. 

E.g.

Lions - one male (alpha male). He mates with all females, so all cubs in his 'pride' are his.

Sealions - same way as lions, alpha male mates with all the females in his 'harem'.

• When an animal is ready to reproduce, they often do courtship behaviour. Males usually do some sort of display to attract a female. E.g. male birds strut around showing off colourful feathers.
• Female birds tend to have dull feathers, to be camouflaged when caring for their young in the nest.
• Females are attracted to males' colourful feathers.

• Incubation - sitting on eggs, keeping them warm until they hatch.
• Feeding - one or both parents leave the nest whilst getting food. they bring it back to feed their chicks.
• General protection - building nes, eggs are camouflaged, attack/ distract predators.

• Gestation/ Pregnancy - provides unborns with protection - greater chance of survival.
• Breast feeding - provides nutrients needed, protects from some diseases, provides a constant and safe place to feed.
• General protection - protect from predators, young gradually learn how to look after themselves.
• Instinctive/ innate behaviours - animals born being able to do them.

• Animal Behaviour - how an animal responds to a stimulus.
• Instincts are inherited from parents, and are not affected by the environment. E.g. suckling by a newborn mammal.
• Some behaviours have to be learned through conditioning. Conditioning can be either operant or classical.

Parental care in animals has evolved to increase chances of offspring carrying on parents' genes.

E.g. killdeer bird - pretends to have an injured wing in order to direct predators away from its nest.

Operant conditioning - animals learn to do things by being rewarded or punished. People condition animals to do things such as:

• train guide dogs for the blind
• dolphins/ sealions to jump through hoops
• sniffer dogs - search for people/ illegal drugs
• train police horses to remain calm in large crowds or loud situations.

• Classical conditioning - animal learns without actually trying, e.g. rattling a dog's lead before a walk.
• Ivan Pavlov - russian scientist. Dogs salivate when shown food. Bell rang each time dogs were shown food. Eventually, dogs salivate when the bell is rung.

• Simplest way of learning.
• Animals stop responding to a stimulus (ignore it) when they realise it has no effect on them.
• E.g. cat ignores the bell on its collar.

Imprinting - behaviour seen in young animals - copying parents.

E.g. young birds follow their parents as they walk. If newly hatched birds first see another animal, or even an object, they can imprint on them instead.

Animals use communication to :

• warn each other of danger
• work together when hunting
• attract a mate

Ways of communicating:

• making sounds
• producing chemicals (often smells)
• giving signals or displays
• body language and facial expressions.

• Small box separated into different areas. Small animals placed into box to examine their preferences.
• Commonly woodlice:
• Dark/ light
• Moist/ dry.

Most animals communiacte by making sounds. For example:

• some snakes hiss to signal the presence of a predator
• a big cat will produce a low growling sound to let others know they are not welcome on its territory.

Pheromones - chemicals some animals release into their environment. Used to attract mates, scare off competitors, mark territory, or make others aware of their presence.

E.g.

• female dogs, recently given birth, produce pheromones that provide a feeling of comfort, safety and reassurance to their young.
• female moths release pheromones that attract male moths. Males use their antennae to detect sex pheromonres of females.

Signals and displays are used to attract a mate, show submission or present a threat, e.g. rabbits thump hind legs as a warning signal, male birds do displays to attract females.

Body language - communicating intentions through body posture, used to communicate a wide range of feelings and emotions. 

Body language and facial expressions are species-specific.

• Have brightly coloured and strongly scented flowers to attract insects for pollination.
• When attacked by insects, some plants release volatile chemicals (oils) to warn nearby plants.
• Some plants release chemicals that attract the predators of those insects that are attacking them.

Co-evolution - two or more species evolve together to better chances of survival. E.g.

• Hummingbirds and flowers. Hummingbird gets food, flower gets pollinated. Flower colour appeals to birds. Birds' beak is shaped to reach plant's nectar.
• Snapdragon flowers and bees. Flower evolved to snap open for bees.

Some plants have evolved to have markings only seen by bees and some insects. These can only be seen under ultraviolet light.

Old World Swallowtail Butterfly caterpillar - resistant to oils of the Rue plant, that it produces to defend itself. Caterpillars live on the Rue plants.

Nickolaas Tinbergen - dutch ethologist - won Nobel Prize. Most well known for work on innate behaviour in gulls. Chicks instinctively peck at red spots on parents' beaks for food.

Konrad Lorenz - german ethologist - shared Nobel Prize with Tinbergen. Best known for work on imprinting - chicks followed him when they hatched and saw him first.

Dian Fossey - american ethologist - studied mountain gorillas in Africa, they had to become habituated to her. First recorded person to peacefully touch a gorilla. Fould males killed others' young so females mate with them. Spent many years trying to prevent poaching.

Jane Goodall - british ethologist - studies chimpanzees in Africa, first person to observe they have distinct personalities. Observed intimate behaviours such as tickling and hugging. Famously recorded chimpanzees using tools for the first time.

Ardi - female human like fossil skeleton found in Africa, 1992. Dates from 4.4 million years ago. Most complete early human like skeleton found. Analysis of bone structure shows humans and chimpanzees evolved seperately.

Lucy - similar to Ardi, found in Africa. Dates from 3.2 million years ago. Analysis of fossil shows it was likely to have walked upright, like humans, but had a small skull, like apes.

British/ Kenyan archaeologists. In Kenya, Mary found the first fossil skull of a primitive ape. Went on to finds two skulls from extinct species, closely related to man. Their son, Richard, continues their work in this area.

• Man first used tools in Palaeolithic (or old stone) age. These were simple tools, e.g. flint hand axes.
• Remains of more complicated tools found from mesolithic (middle stone) age include arrowheads and spear throwers.

• In ice ages, man changed behaviour to suit conditions, e.g. hunt larger animals in groups, live in communities, didn't travel as far from homes.
• At the end of the last ice age, man migrated across Europe. It is believed that man colonised the Americas by the Bering Straight Bridge, a stretch of land from Alaska to Siberia about 20000 years ago.

• Mitochondrial DNA - DNA present in the mitochondria of animal and plant cells.
• Scientists date fossils by molecular dating, using mDNA.
• By looking at changes in mDNA over time, scientists can construct a 'DNA family tree', with which we can predict when an organism was alive, and its relationship to other organisms.
• mDNA is passed from mother, but mot father.
• Scientists traced back mDNA bto a common female ancestor, African Eve.
• African Eve lived 200, 000 years ago.
• Why use mDNA to track evolution?
  • high mutation rates
  • lack of degradation over time
  • volume in cells
  • inherited down the female line.

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