Behaviour And Evolution Flashcards
What is behaviour
How an organism responds to changes in the environment it can be inherited or learned both genes and environment decide the behaviours
What is innate behaviour
Inherited behaviour
Animals can respond in the correct way to a stimulus as soon as it’s born e.g.
Reflex actions like sneezing coughing and blinking
Earthworms have negative phototaxis Reflex so they move away from the light
Sea anemones wave their tentacles more when stimulated by chemicals emptied by their prey
What is learned behaviour
Animals respond to a changing condition
E.g. Leading from their previous experiences how to act
What is habituation
When you keep on giving an animal a stimulus that isn’t beneficial or harmless then after it happens lots of times they learn to no longer react to the stimulus
This allows animals to spend their time and energy more efficiently
What is imprinting
When an animal learns to recognise its parents an instinctively follows them
It’s a mixture of learned and innate behaviour
The baby animal will imprint to the first moving animal it sees
What is classical conditioning
When an animal changes its response to a stimulus it already recognises
E.g a dog salivates when it smells food but then Pavlov began to ring a bell before he got the food out and the dog began to salivate when it heard the bell instead of when it smelled the food
What is operant conditioning
When an animal by chance does a behaviour which gets it a reward or punishment it learns to associate that behaviour with a reward or punishment so either continues to do it lots to get a reward or stops to avoid the punishment
E.g. If by chance the dog sits then gets a treat then this keeps on happening it will soon learn that when it sits after being told to it gets a treat
How is conditioning used to train animals
Usually by operant conditioning
E.g. Training guide dogs to stop at a road or wait for a response
Training sniffer dogs to retrieve drugs
Training police horses to only respond to commands from its trainer
Why do animals need to communicate
It helps keep the group together
If one animal sees a predator it can warn others
Communication of mood can avoid fighting
Baby animals can communicate their moods to their parents
Communication can allow predators hunting in a pack to communicate with each other
How do animals communicate using sound
Whales and dolphins can communicate long distances using infra sound
Bird calls are used to declare their territory or attract a mate
How do animals communicate using chemicals
Chemicals called pheromones can be released from the animals to tell others where it is
Scents are used to mark out territory
Pheromones can be used to attract mates
How do animals communicate using visual signals
Honey bees do a wiggle dance to show the group where they’ve found food
Mammals mostly use body language and gestures
They can use this to threaten other animals or to admit defeat
Facial expressions
Courtship behaviour such as building nests or dancing
What did Tinbergen do
Studied innate behaviour in herring gulls
Gull chicks know to peck at their parents beak to ask for food
Adult gulls have a red spot on their beak
He showed newly hatched chicks different gull heads some made of cardboard and some more realistic and some with some without red dots
The chicks most often pecked at the heads with red spots which shows the chicks go for the red spot.
What did Lorenz do
He studied how geese chicks recognise their mothers and learn how to follow her around
He took 2 groups of chicks one with their mother one in an incubator the chicks with their mother saw their mother as the first moving
object the ones in group 2 saw Lorenz first
The chicks followed the first moving object they saw
What did Fossey and Goodall do
They studied apes
They found
They are both social animals and like to live in groups
They work together to find food so they can find more
They protect each other from attacks
The male have a social rank which prevents fights
They groomed each other to keep each other clean and reinforce social bonds
What are examples of how animals find mates
Lots of animals make calls or songs usually males
Pheromones are chemicals given off by the female to attract the male
Males can fight each other to get the female the could have physical fights or have competitions
What are courtship displays
The male displays a specific thing to impress the female
E.g. Posturing dancing or showing brightly coloured parts of themselves
Females want the best mate so they can get the best offspring after they out lots of effort into raising them
How do mating patterns vary between species
In most species males take no part in raising the child so he’ll go off and mate with other females
In some species the male mates with the same female for one season
In some mammals a male may have group of females he stays with forever but mates with all of them
Few birds and mammals stay with the same partner
How do animals protect their young
One parent may stay with them to keep them together and fend off predators
They can build nests or homes for the young to live in
How do animals feed their young
If they have to go and find food then both parents will raise the young so that one parent can stay whilst one gets the food
How do animals teach their young skills
Babies watch the parents then imitate their actions
Why do animals look after their young
Increases the proportion of young that survive
Looking after the young is less risky for the mother than being pregnant so if they care for the young they can give birth earlier
It is important for the babies to pass on their genes to the next generation
What are the risks from animals of caring for their young
Food has to be shared
Time has to be spent with the young
They decrease their own chances of surviving from a predator
Why do plants send out chemical signals
Attract pollinators
When the insect comes for the scent of the flower some of the pollen gets stuck to the insect then they pass it onto other plants
Attract insect predators
When being eaten by a Pest they release a chemical that attracts a predator insect to eat the insect but not the plant
How do plants warn other plants
Some plants have chemicals on their leaves that mean they release a signal if they’re being eaten
When another leaf on the plant detects the signal it makes a chemical that makes the plant harder to digest
Plants nearby then detect the signal and prepare themselves in the same way
How have plants and their insect pollinators coevolved
It’s an advantage for an insect to get nectar that no other insect can get
It’s also an advantage for the plant if only one type of insect can pollinate it then that insect is more likely to pollinate flowers of the same type
So some plants and insects have co evolved e.g.
Orchids have really long nectar stores this are only reached by a particular type of moth
How have plants and insects that eat them co evolved
It’s an advantage if plants can produce Nast chemicals that mean most insects can’t sat it
It’s an advantage for the insect if it can eat a plant that other insects can’t
So some insects have evolved to eat poisonous plants e.g. Caterpillars eat ragwort which is poisonous to lots of other animals
How do fossils give us clues about what human ancestors were like
Chimpanzees are our closest living relatives evidence from fossils suggest that humans and chimpanzees evolved from a common ancestor
By looking at humanoid fossils we can be how humans have evolved
Describe arid fossil
4.4 million years old
Ardipithicus ramidus
Feet suggests she climbed trees like an ape
Long arms and short legs like an ape
Brain size same as chimpanzee
Her leg structure and hand structure suggest she walked upright like humans
Describe Lucy fossil
Australopithecus afarensis
3.2 million years old
More human like than Ardi
Arched feet more adapted to walking
Arm and leg size was between ape and human
Brain slightly larger than Ardis but Stil chimpanzee size
Leg bones suggest she walked upright more efficiently than ardi
What did Leakey and his team do
Organised an expedition to Kenya to look for humanoid fossils
He found a fossil from 1.6 million years ago
Short arms and long legs like a human
Brain size similar to human
Leg structure suggests he was more adapted to walking than Lucy
How does stone tools help us date fossils
By studying rock layers so tools in deeper layers are older
We can date fossils found with tools
We can use carbon 14 to date any material found with the tool that is made from carbon
The more complex the stone the younger the fossil because simpler tools are older and as brains developed more we learned how to make more complex tools
How does mitochondrial DNA provide evidence for human evolution
It only comes from the mother
The more different two mitochondrial DNA are the further back their common ancestor was
It proves everyone decided from one woman ‘mitochondrial eve’
Mitochondrial DNA can have mutations but scientists have studied the mutations to finde that eve was an african woman 200 000 years ago
This means Homo sapiens must have evolved in Africa then spread across the world
Why is mitochondrial DNA more useful than nuclear DNA
There’s lots of mitochondria in a cell so lots of copies
Mitochondrial DNA is less likely to degrade over time
How did migration cause changes in human behaviour
As humans migrated out of Africa they encounter lots of new environments and gradually changed their behaviour so they could survive
How did humans change when migrating to the coast of the near east and Asia
They changed their diet and began to eat shellfish and seafood
They had to invent new stone tools to get shellfish out of their shells
How did migration to Australia change human behaviour
People in rainforests started to eat fruit that grew in trees
They had to get new tools to be able to reach the fruit
How did migration to Europe change human behaviour
They changed their diets to include the plants and animals they found
They had to develop new methods of hunting so they could hunt in groups
They built more shelters because the climate was colder
They used animal skins to make themselves cold
How did humans change their behaviour to survive the ice age
They built more shelters or seemed shelter in caves
Used fire to heat the shelters
Wore warm clothes made of fur and animal skin
Hunting for food increased
They made more use of tools
Cooperation and coordination increased because they had to work in groups to survive
