Flashcards in Topic 2 - Behaviour and Evolution Deck (60):
What is behaviour
a responce to changes in the environment helping organisms survive. It is either inherited or learned but most behaviour is a mixture of both
What is innate behaviour?
inherited behaviour. Animals can respond right away to a stimulus even though they've never done it before. It can be a simple reflex or a complicated behaviour like a courtship ritual.
Give examples of reflex innate behaviour
earthworms show negative phototaxis which means they move away from light
sea anemones wave their tentacles more when stimulated by chemicals emitted by their pray
What is learned behaviour?
it lets animals respond to changing conditions. Animals can learn from previous experiences how to avoid predators and harmful food, and how to find food or a suitable mate.
What is habituation
if you keep giving an animal a stimulus that is neither harmful nor beneficial it quickly learns not to respond to it. By ignoring non-threatening and non-rewarding stimuli, animals can spend their time and energy more efficiently. This is an especially important learning process in young animals - they are born with an inherited tendency to be frightened of loud, bright, sudden stimuli and they must quickly learn which stimuli to ignore so they can concentrate on stimuli that are possibly dangerous.
What behaviour is a mixture of innate and learned?
Imprinting - when an animal learns to recognise its parents and instinctively follows them. it occurs in species which can move soon after they are born. New born animal has an instinct to follow the first moving object it sees (usually a parent, who provides shelter and food) but the animal has no innate instinct of what its parents look like
What are the two types of conditioning?
What is classical conditioning?
When an animal learns passively (without trying) to associate a 'neutral stimulus' with an important one.
Give an example of classical conditioning
He studied the behaviour of dogs and noticed they would salivate every time they saw of smelt food. he began to ring a bell just before they were given food. After a while the dogs salivated when the bell was rung even if they weren't given food
What is Operant conditioning?
"Trial and error"
where the animal actively learns to associate an action with a reward or a punishment. This happens in humans when children are rewarded or punished for specific behaviour.
Give an example of operant conditioning
Trained rats and pigeons to obtain a food reward using a small cage he invented. The animal had a choice of buttons to press. When one of the buttons was pressed it was rewarded with food.
He noticed that pigeons and rats used a system of trial and error to learn which button to get the reward
How do we use conditioning?
We use both types to train animals but mainly operant. It can be a reward such as food for doing what you want or punishment for doing something wrong. Punishment is no longer recommended for animals.
Give examples of how we use operant conditioning to train animals
Guide dogs to stop at a roadside and wait for a command
Police sniffer dogs to retrieve drugs
Police horses to only respond to commands from their rider
How do we use a mixture of both types of conditioning
Used when reward can't be given at the exact tome the act is carried out.
For example a dolphin can't always be rewarded with a fish at the exact moment it does a jump. The trainer gets the dolphin to learn to associate a whistle with getting fish then whistles when the animal does the jump. The whistle is the reward as it tells the dolphin it will be getting a fish
Why do animals need to communicate
it can help keep the group together
can warn others of predator
communication of mood can avoid unnecessary fighting
baby animals can communicate their needs to their parents
allows predators hunting in a pack to coordinate their attack.
What different ways do animals communicate
How is sound used for communication
Whales and dolphins use low frequency sound to communicate over long distances
birds' calls are used to declare their territory, attract a mate, or warn of predators
How are chemicals used for communication
Chemicals called pheromones can be released by an animal to tell others where it is or where it has been.
Many animals use chemical 'scents' to mark the boundaries of their territory
Other chemicals can act as sexual attractants. e.g in some moths the male can detect the females pheromone even if he is several km away
How are visual signals used for communication
Some animals use specific visual signals to communicate
honey bees move in a certain way called a 'wiggle dance' when they return to the hive to tell others they found food
Most mammals can communicate certain intentions through their body posture and gestures.
many use behaviours to threaten others to avoid a fight - chimps do this by staring or raising an arm
also used to admit defeat - dog rolling on its back is showing submission
facial expressions. they are different to different species.
What is an ethologist?
they study Animal behaviour
What did Tinbergen study.
Innate behaviour in herring gulls.
Newly hatched gull chicks know how to peck their parents beaks to ask for food. Adult gulls have a red spot on their beak and Tinbergen wanted to know if it was the red spot that made chicks want to peck.
He showed newly hatched chicks cardboard gull heads with different coloured spots on the beak. He counted the number of times the chicks pecked different spots at a given time,.
the chicks pecked at the beaks with red spots most often. Tinbergen concluded that the chicks are born with an instinct to peck at the red spot
What did Lorenz study
He studied how baby bird like ducklings and goose chicks recognise their mother and learn to follow her around.
He took two groups of goose eggs. Group 1 were hatched out by their own mother while group 2 were hatched in an incubator with no mother
the first moving object the chicks in group 1 saw was their mother, group 2 was Lorenz.
Group 2 treated lorenz the same as group 1 treated their mother - they followed him around
goose chicks had formed an attachment to the first moving object they saw
What did Fossey and Goodall study?
social behaviour in apes
Fossey studied mountain gorillas in Africa
Goodall studied chimpanzees in Tanzania.
they observed their behaviour in natural habitat to not disturb them and recorded what they saw.
Both apes are social animals - they live in groups and show social behaviour:
Apes worked together to search for food sources so they found more food
they protected each other from attacks
all males had a social rank which helped prevent fights because everyone knew their place.
Groomed each other which helped to keep them clean but also reinforced the social bonds within the group, helping to keep it together.
They also strengthen bonds by showing affection
What experiment can you do to investigate animal behaviour
Set up choice chamber with 4 sections, A, B, C, D.
Cover A and C with black paper
put damp paper in C and D
put 12 woodlice in the middle, put lid on and leave for 10 min
record the number of woodlice in each area
Make sure other conditions such as temp and size are the same
How do animals attract a mate
some animals make some sort of song or cals to attract mate. the male usually make the call to attract the females. e.g birds, whales, frogs
Some insects use pheromones as sexual attractants, usually the female. e.g moths
Some males fight each other and only the winners get to mate e.g deer. sometimes not real fights, as number in species would decrease, sometimes displays to indicate strength and give weaker male chance to back away.
courtship displays usually involve male doing special display to impress female. Involve things such as exaggerated posturing, dancing, showing brightly coloured parts of the anatomy. often species specific so female knows she is dating the same species. often link between impressiveness of display and fertility of male.
Why do females choose the male
males put in more effort to attract female but female must make sure so breeds with same species so fertile offspring is produced. has to choose male that is strong and fertile to ensure the next generation will have best possible chance of survival. males have to show they are worthy of selection
Describe some mating patterns
in most species the male takes no part in birth or care for young so no reason to stay, he will go and mate with other females during the same mating season
Some species (e.g some birds) mate with one female each season but not necessarily the same one each season
in some mammals the males will have a group of females which he stays with and mates with them all. The females are known as his harem.
Which animals are monogamous
birds - albatross, bald eagle, swan, mallard, penguin, parrots
mammals - gibbons, prairie dogs
What three ways do parents look after their young?
How do parents protect their children?
can involve just staying with young to keep them together and fend off predators. in some cases protection is helped by the construction of elaborate nest to enclose the young e.g the weaver bird
how do parents look after their young by feeding?
if a species both feeds and protects young then both parents are usually involved. one to get food whilst the other stays with young
How do parents look after young by teaching skills
young animals need to be taught certain behaviours to ensure survival that aren't innate. Parents must teach them how.
Oystercatchers get food by opening mussels so must be taught, takes young months to learn but adults can do it in less than a minute
human babies need to be taught a whole range of skills and often learn by imitating parents
How does looking after young but mothers at risk
food has to be shared and a lot of time has to be spent with the eggs and baby animals. If parents protect young from predators they decrease their own chance of escaping
How does looking after young increase the chances of survival?
Increases proportion of the young that survive. In birds that care for their eggs 25% of eggs will produce adult birds which is high compared to most animals.
Looking after young is less risky for the mother than being pregnant which puts strain on her body and makes it difficult to escape predators, so if animals care for young they can give birth to less developed young and so have shorter pregnancy (only applies to mammals)
Genes are passed on to next generation are important rather than survival of the animal itself. this may be why animal will risk death to protect offspring which contain its genes
Why do plants send out chemical signals to attract insects
attract pollinators - flowers release smelly chemicals to attract insects that pollinate the flower
Attract insect predators - some release chemicals into the air when insect pest is eating them, these chemicals attract a predator insect that feeds on the pest not the plant. predator gets food plant gets protection
Why do plants release chemicals to warn plants
some plants have leaves that release chemicals if they are being eaten by insects to warn other plants. The other plants then makes chemicals that make the leaf harder to digest.
What is co-evolution
where two organisms evolve in response to each other
why is co-evolution between plant and their insect pollinators good for each organism
its an advantage for an insect if it can reach the nectar in a particular type of flower that other insects can't reach.
advantage for the plant if only one type of insect can get nectar as that insect is more likely to visit the same type of flower and pollinate it.
e.g orchids have really deep nectar stores and are pollinated by a type of moth that has evolved a really long mouth part to reach its nectar
Give an example of co-evolution between plants and insects that eat them
its an advantage if a plant can produce nasty chemicals so most insects don't eat it
its an advantage for an insect if it can eat a plant that other insects can't
some insects evolved to eat poisonous plants e.g caterpillars of the cinnabar moth eat ragwort which is poisonous to other animals
What is our closest living relative?
What does evidence from fossils tell us about our ancestors
chimpanzees and humans evolved from a common ancestor that existed 6 million years ago.
What are human beings and their ancestors known as
What is 'Ardi'
A Fossil Hominid 4.4 million years old from the species Ardopithecus ramidus.
has mixture of features found in humans and apes:
structure of feet suggests she climbed trees - ape like toe to grasp branches
had long arms and short legs - more like ape than human
Brain size was the same as chimp
Structure of legs suggests she walked upright like human. structure of hand bones suggests she didn't use hands to help her walk like apes
What is 'Lucy'
Fossil Hominid 3.2 million years old from the species Australopithecus afarensis.
mixture of both features but more human than Ardi:
Arched feet more adapted for walking than climbing. no ape big toe
Size of arms was between what you would expect on apes and humans
Brain was slightly larger than Ardi's but still similar to chimps
Structure of leg bones and feet suggest walked upright but more efficiently than Ardi
What did Leaky discover
found many important fossils of different Australopithecus and Homo species on an expedition in Kenya.
One of their finds was Turkana Boy - fossil skeleton of Homo erectus and is about 1.6 million years old.
Mixture of human and apes features but more human than lucy
Short arms and longs legs like humans
brain size much larger than lucy's - more human than ape
structure of legs and feet suggest better adapted to walking than lucy
What other evidence is there for human evolution
development of stone tools
How do stone tools provide evidence for evolution
they began to get more complex so their brains must have been getting larger
How did Homo habilis use stone tools
made simple stone tools called pebble tools by hitting rocks together to make sharp flakes. they could scrape meat from bones or crack bones open
How did Homo erectus use stone tools
sculpted rocks into shapes to produce more complex tools like simple hand axes which could be used to hunt, dig, chop, and scrape meat from bones
How did Homo neaderthalis use stone tools
more complex tools. evidence of flint tools, pointed tools and wooden spears
How do Homo sapiens use stone tools
flint tools widely used. pointed tools including arrowheads, fish hooks, buttons, and needles appeared around 50,000 years ago
How can we work out how old a stone tool is found
stratigraphy - study of rock layers. older rocks are usually found below younger later so tools in deeper layers are older
dating fossils found with stone tools
using carbon-14 dating to date any material found with it that is made from carbon e.g wood handle
How is mitochondrial DNA used to provide evidence for evolution
Mitochondria have small piece of DNA inside them. it is inherited from the mother so is not mixed with DNA from father
the more different two mitochondrial DNA samples are the further back they shared a common ancestor.
everyone on planet has similar mitochondrial DNA showing everyone is descended from one woman called 'Mitochondrial Eve' by scientists.
some bits of mitochondrial DNA do vary due to mutations which occur often as mitochondrial DNA has high mutation rate
Mitochondrial Eve is an African woman who lived 200,000 years ago ('African Eve')
What does the discovery of Mitochondrial Eve show
Homo sapiens must have evolved in Africa then spread from there across the world
Why is nuclear DNA less useful
it can be used to study human evolution and migration but mitochondrial DNA is more useful because:
Lots of mitochondria in a cell so there are lots of copies of mitochondrial DNA
Less likely to degrade over time
How has migration caused change in human behaviour
As humans moved out of Africa they came into contact with new environments, and they gradually changed their behaviour to survive.
they first moved to coastal areas of the Near East and Asia, then on to the hotter lands that would become Australia and finally to Europe with its cold climate
How did Humans change in the coast of the Near East and Asia
Changed their diet - started to eat shellfish and other seafood. Also meant that they had to invent new stone tools to get the shellfish out of the shells
How did Humans change in Australia
Rainforest settlers started to eat the fruit that grew in trees. this meant new tools to reach it
How did Humans change in Europe
Changed diet to include the new plants and animals they found
many animal species they found were large animals so had to devise new methods of hunting so that they could hunt in groups. also meant making new tools like knives and saws.
climate was colder so they had to build shelters
humans settling in these cold areas been to use animal skins to make themselves warm clothes