Download suited to the environment

STEP 4
Warm-up/ speaking brainstorming ( what did Darwin find on the islands?, were
there any birds? If so, which ones do you remember?)
Now look at the bird . Think about the function of …….
The wings (es, it can fly…)
The eyes
The legs
The claws
Write the right title before each paragraph: NATURAL SELECTION –
DARWIN’S FINCHES – DARWIN’S THEORY OF EVOLUTION (pair work)
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Darwin studied the wildlife on the Galápagos Islands. He noticed that the finches - songbirds - on
the different islands were fundamentally similar to each other, but showed wide variations in their
size, beaks and claws from island to island. For example, their beaks were different depending on
the local food source. Darwin concluded that, because the islands are so distant from the
mainland, the finches that had arrived there in the past had changed over time.
Consistent environmental differences in different habitats on different islands in the Galapagos, as
well as the availability of different foods sources, have produced more than a dozen distinct
species of finches, all unique to the archipelago (ADAPTATION).
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Darwin started to think about the meaning of all he had seen on his journey as soon as he
returned to England. He became certain that all creatures had developed, or evolved, slowly over
time to adapt to different situations. This was not a completely new idea, but Darwin took it
further than anyone else. He realised that:
1. plants and animals were divided into separate species, or groups which had similar
features.
2. members of each species, or group, could only mate with each other to produce fertile
offspring.
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Darwin observed that successful species can produce more offspring in each generation than are
needed to replace the adults which die.
Darwin decided that some creatures or plants struggle to survive. Many things affect an
individual's chances of survival, including its ability to get enough food and to escape being killed
by others. He also realised that individuals in a particular group or species are not identical.
Sometimes there are differences which may make it easier for that individual to survive long
enough to produce more offspring. For example, some may have different coloured fur or skin so
that they are less easily seen. If these individuals mate with each other, they are likely to pass on
the advantage to their offspring. Gradually more and more of that species would have the
different coloured fur. The species would have changed, or evolved. Darwin called this process
'natural selection', and it was one of his most important ideas.
He explained in the book called 'On the Origin of Species' which was published in 1859.
Darwin
developed his own ideas on natural selection. He later used these ideas to explain how humans
had evolved from earlier ancestors. His book 'The Descent of Man' was published in 1871.
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The basic idea behind the theory of evolution is that all the different species have evolved from
simple life forms. These simple life forms first developed more than three billion years ago - the
Earth is about 4.5 billion years old.
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The timeline below shows some of the key events in the evolution of life
forms on Earth, from the first bacteria to the first modern humans.
The theory of evolution states that evolution happens by natural
selection. Here are the key points:
Individuals in a species show a wide range of variation.
This variation is because of differences in genes.
Individuals with characteristics most suited to the
environment are more likely to survive and reproduce.
The genes that allowed the individuals to be successful are
passed to the offspring in the next generation.
Individuals that are poorly adapted to their environment are less likely to
survive and reproduce. This means that their genes are less likely to be
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passed to the next generation. Given enough time, a species will gradually
evolve.
TURE OR FALSE? CORRECT THE FALSE STATEMENTS (group work)
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2.
3.
4.
5.
6.
7.
8.
9.
The finches were all identical
They came from the same mainland finch
There were only two distinct species of finches on the Galapagos
The finches had arrived there many years before Darwin’s arrival
The finches were different because they had adapted to the
different situations (e.g. food, environment,…)
Darwin studied only birds
He published only one book
Adaptation and natural selection are the two most important
principles of his theory
All the different species have evolved from very complex life forms
GROUP WORK
IN YOUR OWN WORDS EXPLAIN THE FOLLOWING CONCEPTS:
 ADAPTATION
 NATURAL SELECTION
LOOK AT THE CHARTS ON THE FINCHES. WHAT DO THEY SUGGEST?
LOOK AT THE PHOTOS SHOWING DIFFERENT FINCHES. Classify
them.
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LOOK AT THIS PICTURE. DESCRIBE IT .
WHAT DOES IT SUGGEST?
FOR THE NEXT LESSON EACH GROUP HAS TO PREPARE A POWER POINT
PRESENTATION (NO LONGER THAN 5 MINUTES/MAX 10 SLIDES) TO SUM
UP THE CONTENT OF THE CLIL ACTIVITIES ON CHARLES DARWIN.
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