Starter

1) Pick up 1 worksheet and 1 information sheet

2) Glue it into your books3) Answer the questions

4) You have 11 minutes =)

What is evolution?

Evolution has the answer(Glue the 2 sheets into your books and copy down the objectives)

Objectives:•describe how the effects of mutations, natural selection, isolation and environmental change can cause new species to evolve

•explain how scientists can make predictions about what might fill ‘gaps’ in the fossil record

What do all of these have in common?

• They share a common ancestor.• Humans have not evolved from monkeys.• Humans began to evolve separately from monkeys about

30 million years ago, but one did not evolve from the other

Task 1

Answers:a) genes; b) offspring; c) more often than

other genes; d) very long periods

of time; e) fertile offspring; f) species

Common ancestors

Common ancestors• Explain why

humans and gorillas are not the same species.

• Which two species are the most closely related to humans? Why?

• What features do all of these have in common?

Evidence of evolution

• How do we know about previous species?

• Define what the ‘fossil record’ is.

• information gathered from all the known and recorded fossils in the world

• How do scientists make predictions about what an organism in the fossil record might look like?

Example

Lizard bird

• Scientists predicted that a group of reptiles evolved into birds; what intermediate fossils might they have predicted they would find?

• In what conditions is a mutation that gave a lizard rudimentary wings (remember, the wings are formed from the front legs) might have been useful.

• For example, for a tree-dwelling reptile escaping from a predator even a rudimentary pair of wings might have given some advantage in jumping further from tree to tree or gliding a little way.

• Even a slight improvement in the chances of having offspring will mean that the mutated gene will become more frequent in the next generation.

• If the change became so dramatic that the original reptiles and those with wings were unable to produce fertile offspring together, a new species would have been formed.

Skull reconstructions of 3 human species: Homo erectus, Homo neanderthalensis and Homo sapiens

• Human evolutution - Part 1• http://www.youtube.com/watch?v=r_bBEYK_6wE

Task 2• Match the

numbered boxes to the letters in the table.

• A−4; • B−1; • C−2; • D−3

Plenary Q’s

1. Why do some traits caused by mutations get passed on?

2. Why does isolation lead to more species being formed?

3. What happens if the environment changes too quickly for species to adapt?

4. Did humans evolve from monkeys?5. What is the ‘tree of life’?

Answers1. Why do some traits caused by mutations get passed on?

(The organisms with traits that are useful are more likely to reproduce)

2. Why does isolation lead to more species being formed?(Natural selection acts on each group of organisms separately)

3. What happens if the environment changes too quickly for species to adapt? (The species will become extinct)

4. Did humans evolve from monkeys?(No; they had a common ancestor about 30 million years ago)

5. What is the ‘tree of life’?(Diagram showing the evolutionary relationships between species)

Tree of life

Task 3 - answers

• Q1 About 3500 million years ago. • Q2 There is such a vast range of habitats

available on Earth.• Q3 Scientists have been able to pinpoint using

DNA the points at which organisms shared a common ancestor.

• Q4 It is shaped like a tree, with branching paths; at each node of the path, organisms on the following branches share a common ancestor.

The story of human evolution

• Part 2 - http://www.youtube.com/watch?v=KRCkl2GhT0E

• Part 3 – http://www.youtube.com/watch?v=T94ypasgNQI