Brugklas Evolution - Vestigial organs and fossil record

• Biologie
• Middelbare school
• vwo
• Leerjaar 1

chapter 4: Evolution

What can looking at skeletons tell us?

Skeletons can tell us about the past

-Skeletons change over time

-how bones are shaped can tell us something about the past

Vestigial organs: 

Organs that an animal has but doesn't use anymore

Example:  Tail bone 

Example:
Pelvis/Femur in whale 

Vestigial organ with no function:

Leg bones in snakes -> Tickle females during mating

Vestigial organ with new function

Vestigial organs show that animals have changed over time

Fossils

Also show that animals and plants have changed over time

The organism is quickly covered with a layer of sand or mud

Why are there not so many early fossils?

1. Early forms of life were soft bodied organisms
2. No animals were living a long time ago
3. Bones of those animals were never found
4. What are fossils again?

Fossils and vestigial organs show us that organisms changed over time. What is the theory called that explains what makes animals change?

Charles Darwin

1809-1882

Species could change over time to become better adapted to their environment

This change is called evolution

What is natural selection?

1. organisms can change during their life
2. more organisms are born than there is room or food for.
3. predators only eat yellow colored insects
4. the organisms that are best adapted survive

Natural selection

Individuals that are best at surviving in their environment will produce more offspring 

https:

Evolution in Steps

1. More individuals will be born  that can survive 'struggle for existence'
   
2. Individuals with an advantage have a higher chance of surviving ' natural selection' 
   
3. The individuals that survive will have a higher chance to produce offspring 
   

Artificial selection

Not nature is selecting but humans

Humans select the individuals they like best 

Artificial selection

Not nature is selecting but humans

Humans select the individuals they like best 

sexual selection: female choice

What is different between artificial selection and natural selection

1. Nothing, its basically the same
2. Natural selection has to do with survival, artificial selection not always
3. artificial selection is dependent on nature alone, natural selection is not.
4. Natural selection is done by humans, artificial selection not

The dog breeds we have today were developed through:

1. natural selection
2. artificial selection (selective breeding)
3. sexual selection
4. acquired selection

Assignment

• Go to classroom and answer the questions in the ' Natural Selection'  worksheet
  
• Next Monday there will be a QUIZ about the glossary words
• Practice for the quiz using quizlet there is a link on classroom

Evolution

species change over time so they become better adapted to their environment

Struggle for survival: 

More organisms are born than can survive. They compete for food, space and mates.

Natural selection

Individuals that are best at surviving in their environment will produce more offspring