1. Funky Pigeons Revealing the biology of
inheritance and
selection
Lesson 1
Artificial Selection and Genetics
Picture courtesy John Ross: darwinspigeons.com

2. Charles Darwin ( )
“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
The variation of animals and plants
under domestication, 1868

3. Amassing evidence of variation from a common ancestor
The Rock Dove
English Fantail
African Owl
English Carrier
English Barb
English Pouter

4. The power of selection: change is possible
5000 yrs
© Mair Shepherd
Picture courtesy John Ross: darwinspigeons.com

5. Amassing evidence of variation from a common ancestor

6. Natural versus Artificial Selection
Natural Selection
Artificial Selection
Environment
Humans
Cause
Slow
Fast
Speed of change
The selected trait improves
the organism’s chances of
surviving and reproducing
The trait is desirable to
human breeders
Reason for selection
occurring
Improves fitness (although
only for the circumstances
in which it is selected. If
conditions change, the
selected trait may no
longer be advantageous)
Often causes decrease in
fitness
Effect on fitness

7. The wild pigeon
Picture by Christine Matthews (commons.wikimedia.org)

8. Allele for pigeon colour
The allele - Black S, Blue s+
Black is dominant
SS or S s+
Blue is recessive
s+s+

9. Darwin on genetics
“...but it will now be seen that when two birds belonging to distinct races are crossed, neither of which have, nor probably have had during many generations, a trace of blue in their plumage...they very frequently produce mongrel offspring of a blue colour...”
Charles Darwin The variation of animals and plants under domestication, 1868

10. Pigeon feather colour

11. Pigeon colour/pattern phenotypes
Solid black
Chequered
Barred
Barless
© Genetics Society of America. From Genetics September 1, 1922 vol. 7 no. 5  STUDIES ON INHERITANCE IN PIGEONS. IV. CHECKS AND BARS AND OTHER MODIFICATIONS OF BLACK by Sarah Van Hoosen Jones.

12. Epistasis Dominant alleles mask the action of recessive alleles
Epistasis is an interaction between genes: the action of one gene masks the action of another
The epistatic gene masks the action of the hypostatic gene