How do Scientific Theories
Change Over Time?
Science Objectives
By the end of the lesson you will be able to…
…describe three theories that come before evolution.
…describe how Scientific theories change over time.
Skills Objectives
By the end of the lesson you will have demonstrated that
you can work effectively in a team so you all achieve the
content objectives.
Disproved theories match-up: match the theory to how it
was disproved.
Martian Canals: A network of canals on
Mars thought to be a sophisticated
irrigation system developed by an
unknown intelligent species.
Pasteur showed thatr maggots would not
appear on meat kept in a sealed
container. The microscope helped to
show the existence of micro-organisms.
Spontaneous generation:
More powerful telescopes showed that
the canals were streaks for dust blown by
Life arises from inanimate matter like
heavy winds.
slime, mud and earth. Aristotle ‘proved’
this by observing maggots being
‘generated’ by dead bodies and barnacles
forming on the hull of a boat.
A static universe: The universe is the
same size as it always has been and is
not getting any bigger. Einstein
calculated this into his theory of relativity.
Edwin Hubble discovered ‘Red Shift’,
which is how the colour of heavenly
bodies change as they move away from
us.
Team Roles
• Checker; check for understanding and agreement.
• Praiser/encourager; praise effort and ideas.
• Recorder; record ideas and decisions.
• Taskmaster; bring your team back to the task.
• Gatekeeper; make sure all participate (no bully, no loafer)
• Reporter; Share with other teams, the class, the teacher.
• Researcher; Sorts and identifies important information for the team.
Match up the theories to the person who thought of it and when they did it.
Theory
Time
Person
Theory of Spontaneous Generation: living
things can come from non-living matter.
The idea came from the observation that
384-322BC
Aristotle
1809-1882
1744-1829
Jean-Baptiste Lamarck
1809-1882
Charles Darwin
maggots come from dead bodies.
Inheritance of Acquired Characteristics:
Animals develop parts of their bodies to
help them survive. This change is passed
on to their offspring. For example giraffes
stretch to reach leaves high on trees and
this is passed on to their offspring.
Theory of Evolution – animals that have
useful characteristics survive better than
those that don’t so the useful
characteristics are passed on to their
offspring.
Your research task
Find the answers to:
• What was the evidence for the theory?
• Why did people believe it?
• What didn’t make sense about the theory?
• How was the theory disproved?
• Why was this?
Make sure you stay in the role on your role card.
Envoy
• One person from your group will visit another group.
They will take their expertise in your theory with them.
• The ‘envoy’ will teach the new group all about their
theory.
• The group being visited will then share their information
about their theory.
• Then all of the new group will decide:
– Which theory came first?
– Which theory is more accurate?
– Are there any links between the two theories?
Create a Timeline
• Back to your old group.
• Create a timeline of all theories.
• Your teacher will question the timeline to
see how well you understand how theories
change over time.
In a lift…
• You are in a lift that goes to the top of the
Beetham Tower.
• It takes 90 seconds to get to the top.
• Pupil 1 has 30 seconds to say what they
learned.
• Pupil two has 30 seconds to say how they
learned it.
• Pupil 3 has 30 seconds to say why the
learning is important.