Transcript Darwin’s old study at Down House

Unit 3
Designer Animals
Artificial and natural selection - Darwin’s pigeons: Unit 3
What type of animal are they?
• Similarities
• Differences
Artificial and natural selection - Darwin’s pigeons: Unit 3
Pigeons!
Artificial and natural selection - Darwin’s pigeons: Unit 3
Pigeon feather colour
Artificial andDarwin’s
natural selection
ways of working:
- Darwin’s
Unit
pigeons:
1
Unit 3
Pigeon beaks
Artificial andDarwin’s
natural selection
ways of working:
- Darwin’s
Unit
pigeons:
1
Unit 3
Pigeon crops
Pigeon’s
crop
Artificial andDarwin’s
natural selection
ways of working:
- Darwin’s
Unit
pigeons:
1
Unit 3
Charles Darwin
1809 -1882
Artificial and natural selection - Darwin’s pigeons: Unit 3
Charles Darwin the pigeon breeder
Artificial and natural selection - Darwin’s pigeons: Unit 3
“…I do not believe that any
ornithologist would place the
English carrier, the short-faced
tumbler, the runt, the barb, pouter,
and fantail in the same genus…”
Darwin knew they were all
the same species but they
look so different that they
could be mistaken for totally
unrelated birds.
Artificial and natural selection - Darwin’s pigeons: Unit 3
Wild pigeon (rock dove) to fantail
Artificial and natural selection - Darwin’s pigeons: Unit 3
Breeding cycles
!
Mr Jones breeds pigeons.
One day a pair are mated…
And lay eggs.
Mr Jones notices that one baby
pigeon has extra tail feathers.
Many, many years pass ….
He would like more pigeons with extra tail feathers so he decides to breed
from this unusual pigeon. He does this many times, breeding more and
more birds with extra tail feathers, always choosing those with the most
feathers to breed again.
He gives some of these birds to other breeders who
breed them in the same way. After a very long time the
magnificent fantail pigeon is produced.
Table 1
Offspring - Number of tail feathers
Mother
Father
A
A
13
Total
offspring
14
D
8
2
3
E
9
2
0
F
10
0
0
D
12
0
0
E
13
0
0
F
9
0
0
D
11
1
2
E
14
2
1
F
12
0
0
E
A
A
F
A
B
12
B
D
E
B
B
B
F
B
D
C
C
E
C
C
F
C
A
13
B
Total offspring with
more than 12 tail
feathers
5
Table 2
Pigeon
Number of offspring with
more than 12 tail feathers
A
B
C
D
E
F
7
‘Although man does not cause variability
and cannot even prevent it, he can select,
preserve, and accumulate the variations
given to him by the hand of nature in any
way which he chooses; and thus he can
certainly produce a great result.’
Charles Darwin
Referring to your learning
today re-write this quote in
your own words.
Artificial and natural selection - Darwin’s pigeons: Unit 3