AJD C 00285296 3724 424a 9bf7 b924255524c2 doc 18 08 09 Name Evolution “ Da r ts” S hee t How did we get here Scientists have a theory based on “Evolut by coryelJudie

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									AJD C:\..\00285296-3724-424a-9bf7-b924255524c2.doc 18/08/09
                                                       Name________________________________

                         Evolution                              “ Da r ts” S hee t
  How did we get here? Scientists have a theory based on “Evolution by Natural Selection”, first
                             proposed by Charles Darwin in 1859.

Animals inherit their characteristics from their ________. The male and the female
each supply ______ of the genetic information. But sometimes this goes wrong, and
we get a random ___________, which produces different characteristics in the baby.

Here are two examples :-
 1. We think that giraffes used to have much shorter necks. But imagine that food
    was scarce – any _____ necked mutations would still be able to feed, as they
    could reach high _________.
    So they would live long enough to _______, and the others wouldn’t.
    Eventually all __________ would be descendants of the long _________ ones.

 2. Some rabbits can run faster than others. The ones that can run _____ are more
    likely to be able to escape from ____________, and so will live long enough to
    have babies. Their babies will also be able to ____ fast.
    The slower rabbits won’t live as long, and so won’t live long enough to ______.
    So after a while, _____ running will become more common in rabbits, as the
    ______ ones die out.


    So any random mutations which have a high survival value tend to do well,
         whilst others tend to die out. This is called “Natural Selection”.

Humans can cause this to happen much quicker, by Selective Breeding. We have
mated certain _______ to produce the fastest runners for racing. Cows have been
bred to produce more ______. Broccoli, _____________ and curly kale all started
as the same type of plant.
We have mated different types of dog to produce the many different breeds we see
today, but the trouble is that although humans like them, some of theses breeds have
_________ such as weak legs or breathing difficulties.

Words you will need :-

milk                          necked                          half              faster
predators                     run                             breed             fast
parents                       long                            breed             slow
horses                        mutation                        branches          giraffes
                              problems                        cauliflower
AJD C:\..\00285296-3724-424a-9bf7-b924255524c2.doc 18/08/09
                                                       Name________________________________

        Evolution                              “ Da r ts” S hee t           ANSWERS
  How did we get here? Scientists have a theory based on “Evolution by Natural Selection”, first
                             proposed by Charles Darwin in 1859.

Animals inherit their characteristics from their _parents. The male and the female
each supply _half_ of the genetic information. But sometimes this goes wrong, and
we get a random _mutation__, which produces different characteristics in the baby.

Here are two examples :-
 2. We think that giraffes used to have much shorter necks. But imagine that food
    was scarce – any _long necked mutations would still be able to feed, as they
    could reach high _branches.
    So they would live long enough to _breed_, and the others wouldn’t.
    Eventually all _giraffes_ would be descendants of the long _necked__ ones.

 2. Some rabbits can run faster than others. The ones that can run _faster are more
    likely to be able to escape from _predators__, and so will live long enough to
    have babies. Their babies will also be able to _run fast.
    The slower rabbits won’t live as long, and so won’t live long enough to breed_.
    So after a while, _fast running will become more common in rabbits, as the
    _slow_ ones die out.


    So any random mutations which have a high survival value tend to do well,
         whilst others tend to die out. This is called “Natural Selection”.

Humans can cause this to happen much quicker, by Selective Breeding. We have
mated certain _horses to produce the fastest runners for racing. Cows have been
bred to produce more _milk_. Broccoli, _cauliflower__ and curly kale all started
as the same type of plant.
We have mated different types of dog to produce the many different breeds we see
today, but the trouble is that although humans like them, some of theses breeds have
_problems such as weak legs or breathing difficulties.

Words you will need :-

milk                          necked                          half            faster
predators                     run                             breed           fast
parents                       long                            breed           slow
horses                        mutation                        branches        giraffes
                              problems                        cauliflower

								
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