Transcript 1.8_Evolution

What was the principle behind Darwin's theory
of evolution?
Explain Lamarck’s theory of
evolution.
What sort of time period does evolution
normally happen over?
What can cause it to happen more quickly
when there is a change in the environment?
Give three reasons why Darwin's
theory of evolution was only gradually
accepted:
Outline the key principles of natural
selection,
Use the evolutionary tree diagram on
the right to answer the following
questions:
Which group of organisms are most
closely related to Birds?
Fill in the gaps in the table below.
Are fish or mammals more closely
related to dinosaurs?
Explain how a mutant gene that allows
a group of people who live in the
Philippines to develop gills could result
in all humans being able to breathe
under water in 100 years time.
Fish
Body
covering
Where it lives
Reptiles
Birds
Mammals
Moist skin
Lays eggs
with leathery
shell
How offspring
are produced
How it
breathes
Warm or cold
blooded
Amphibians
Lungs
cold
cold
Land
Land
What was the principle behind Darwin's theory
of evolution?
All species evolved from simpler life forms
that first developed more than 3 billion years
ago
Give three reasons why Darwin's
theory of evolution was only gradually
accepted:
•Challenged religion – idea that god
made all living organisms
•Insufficient evidence at time
•Mechanism of inheritance not
discovered until 50 years later
Outline the key principles of natural
selection,
• Organisms within a species show
variation due to mutation causing
differences in their genes
• Some of these genes will give
characteristics that increase changes
of survival
• These organisms are then more likely to
breed and pass these genes on
Use the evolutionary tree diagram on
the right to answer the following
questions:
Which group of organisms are most
closely related to Birds? Dinosaurs
Fill in the gaps in the table below.
Are fish or mammals more closely
related to dinosaurs? Mammals
Explain how a mutant gene that allows
a group of people who live in the
Philippines to develop gills could result
in all humans being able to breathe
under water in 100 years time.
•Global warming causes flooding so less
land
•Mutant gene = can live in water so
more like to survive
•More likely to pass genes on
•Offspring more likely to survive
•Eventually everyone has gills
Explain Lamarck’s theory of
evolution.
• Variation between organisms
within a species is due to
changes acquired during their
lifetime
• These acquired characteristics
(not genes) are passed on.
What sort of time period does evolution
normally happen over?
Millions of years
What can cause it to happen more quickly
when there is a change in the environment?
Advantageous mutation
Fish
Amphibians
Reptiles
Birds
Mammals
Body
covering
Scales
Moist skin
Scales
Feathers
Fur
How offspring
are produced
Lays soft
eggs
Lays eggs in
jelly
Lays eggs
with leathery
shell
Lays eggs
with hard
shells
Gives birth to
live young
Gills
Lungs, gills,
skin
Lungs
Lungs
Lungs
cold
cold
cold
warm
Warm
Water
Lives part of its
life in water
Land
Land
Land
How it
breathes
Warm or cold
blooded
Where it lives