This lesson contains 24 slides, with interactive quizzes, text slides and 2 videos.
Lesson duration is: 30 min
Items in this lesson
Upcoming lessons
- BS 5.4 en 5.5 Evolution
- BS 6.1 to 6.3 Ecology
Slide 1 - Slide
Unit 5 BS 4 the theory of evolution
Slide 2 - Slide
Evolution
The development of life on Earth:
species appearing, changing and/or disappearing
Slide 3 - Slide
Charles Darwin (1809-1882)
Neodarwinistic evolution theory =
The process by which hereditary traits within a population of organisms change over the generations as a result of genetic variation, reproduction and natural selection.
Slide 4 - Slide
Slide 5 - Video
genetic variation
Slide 6 - Slide
reproduction
Slide 7 - Slide
natural selection
Slide 8 - Slide
What is natural selection?
A
organisms can change during their life
B
more organisms are born than there is room or food for.
C
predators only eat yellow colored insects
D
the organisms that are best adapted survive
Slide 9 - Quiz
Natural selection
Individuals that are best at surviving in their environment will produce more offspring = they are the fittest
Slide 10 - Slide
Evolution in Steps
More individuals will be born that can survive 'struggle for existence'
Individuals with an advantage have a higher chance of surviving ' natural selection'
The individuals that survive will have a higher chance to produce offspring
Slide 11 - Slide
Sexual selection: female choice
Slide 12 - Slide
Arguments for the existence of evolution
- Fossils
- Vestigial organs
- DNA
- Analog and homolog organs
Slide 13 - Slide
Fossils
Also show that animals and plants have changed over time
The organism is quickly covered with a layer of sand or mud
Slide 14 - Slide
Slide 15 - Slide
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
Slide 16 - Slide
Example: Tail bone
Example: Pelvis/Femur in whale
Vestigial organ with no function:
Slide 17 - Slide
Leg bones in snakes -> Tickle females during mating
Vestigial organ with new function
Vestigial organs show that animals have changed over time
Slide 18 - Slide
Slide 19 - Video
homolog organs
analog organs
Slide 20 - Slide
Why are there not so many early fossils?
A
Early forms of life were soft bodied organisms
B
No animals were living a long time ago
C
Bones of those animals were never found
D
What are fossils again?
Slide 21 - Quiz
Fossils and vestigial organs show us that organisms changed over time. What is the theory called that explains what makes animals change?