2. 5.1.U3 Selective breeding of domesticated animals shows that artificial selection can cause evolution.
Selective breeding (also called artificial selection) is the process by which humans breed animals and plants for particular traits
Examples:
Breeding dogs for herding, e.g. sheepdogs or racing, e.g. greyhounds
Cows are bred for milk yield or meat
Crops have been bred for increased yield and/or disease resistance

3. 5.1.U3 Selective breeding of domesticated animals shows that artificial selection can cause evolution.
Selective breeding (also called artificial selection) is the process by which humans breed animals and plants for particular traits
Domestic breeds show great variation compared to wild populations populations subject to only natural variation.
Populations show variation in traits
Individuals which do not show the desired traits are not allowed to breed.
Individuals which show the most desirable traits are chosen to breed together.
The process is repeated for many generations until the entire population shows the desired trait
The next generation will have an increased frequency of the desired trait.

4. 5.1.U4 Evolution of homologous structures by adaptive radiation explains similarities in structure when there are differences in function.
comparative anatomy of groups of animals or plants shows certain structural features are basically similar. Structures or anatomical features having similar basic structure as in other species said to be homologous.
The tale of the limb
homologous structures are those that are similar in shape in different types of organisms
The structural similarities imply a common ancestry
This illustrates adaptive radiation since the basic structure adapted to different niches
homologous structures used in different ways in different species
The more exclusive the shared homologies the closer two organisms are related.

5. 5.1.A2 Comparison of the pentadactyl limb of mammals, birds, amphibians and reptiles with different methods of locomotion.
The pentadactyl limb in vertebrates is an example of a homologous structure

6. 5.1.A2 Comparison of the pentadactyl limb of mammals, birds, amphibians and reptiles with different methods of locomotion.
The pentadactyl limb in vertebrates is an example of a homologous structure
It is adapted to different mode of locomotion in particular environment.
dolphin fin for swimming
bat wing for flying
monkey hand for grasping
horse hoof for galloping

7. 5.1.A2 Comparison of the pentadactyl limb of mammals, birds, amphibians and reptiles with different methods of locomotion.
The pentadactyl limb in vertebrates is an example of a homologous structure
NoS: Despite the obvious differences all the organisms share the same bones. For example the bones may vary in size and shape, but all vertebrates have five fingered ‘hands’ at the end of each limb.

8. Mating rituals are different
5.1.U5 Populations of a species can gradually diverge into separate species by evolution. 1
If populations, e.g. fruit flies, become separated (e.g. a population is blown by a storm to a distant island). Then it is very likely the population will experience different ecological conditions. 2
Over many generations the shape of the flies, food preference, mating rituals etc. will likely diverge as the result of natural selection. 3
If the island fruit flies migrate back to the mainland they will not easily mate with the mainland flies as:
Mating rituals are different
Because of genetic differences the resulting offspring are infertile 4
Because genes cannot flow between the populations the island fruit flies are said to have evolved into separate species (this process is called speciation).
n.b. islands often have many endemic (unique to that island) species due to the fact that island environments can easily cause species to become separated.

9. 5.1.U5 Populations of a species can gradually diverge into separate species by evolution.
There are many examples of speciation. Darwin famously used the example of the finches on the Galapagos islands.

10. 5.1.U6 Continuous variation across the geographical range of related populations matches the concept of gradual divergence.
Q - which of these birds are the same species and which are different species?

11. Willow Ptarmigan (female) Willow Ptarmigan (male)
5.1.U6 Continuous variation across the geographical range of related populations matches the concept of gradual divergence.
Willow Ptarmigan
(female)
Willow Ptarmigan
(male)
Q - which of these birds are the same species and which are different species?
Red grouse
(female)
Red grouse
(male)

12. 5.1.U6 Continuous variation across the geographical range of related populations matches the concept of gradual divergence.
The Red Grouse and the Willow Ptarmigan where at one time classified as two separate species. The current scientific consensus is that they are both members of the same species (Lagopus lagopus)
It is a common problem in classification to determine when two populations of one species to have sufficiently diverged to become two separate species.
Populations will gradually diverge over time and it is natural to see continuous variation across a geographical range.
The greater the geographical separation and the longer the populations have been separated the greater the divergence.

13. 5.1.A1 Development of melanistic insects in polluted areas.
Variation: Peppered moths (Biston betularia) moths are found in two forms:
The dark form (carbonaria) is normally very rare.
Use the animation to find out about evolution in Peppered moths
Normal environment: In unpolluted areas tree branches are covered in pale coloured
lichens camouflage for the paler form (insularia).
Environmental change: sulphur dioxide pollution kills the lichens and soot (from coal burning) blackens the tree branches.
The moths fly at night to try to find a mate, but, during the day they rest on the branches of trees.
Result: the dark moths are well camouflaged from birds against dark tree branches are many survive to reproduce, but light coloured moths are easily found and predated by birds, few survive to reproduce.
Selective pressure: Predation from birds (and other animals) whilst resting
Evolution: over a number of generations the dark (carbonaria) form of the peppered moth has increased with frequency - the heritable characteristics of the population have changed.

14. 5.1.A1 Development of melanistic insects in polluted areas.
Variation: Peppered moths (Biston betularia) moths are found in two forms:
The dark form (carbonaria) is normally very rare.
Normal environment: In unpolluted areas tree branches are covered in pale coloured
lichens camouflage for the paler form (insularia).
Environmental change: sulphur dioxide pollution kills the lichens and soot (from coal burning) blackens the tree branches.
The moths fly at night to try to find a mate, but, during the day they rest on the branches of trees.
Result: the dark moths are well camouflaged from birds against dark tree branches are many survive to reproduce, but light coloured moths are easily found and predated by birds, few survive to reproduce.
Selective pressure: Predation from birds (and other animals) whilst resting
Evolution: over a number of generations the dark (carbonaria) form of the peppered moth has increased with frequency - the heritable characteristics of the population have changed.

15. 5.1.A1 Development of melanistic insects in polluted areas.
Variation: Peppered moths (Biston betularia) moths are found in two forms:
The dark form (carbonaria) is normally very rare.
Normal environment: In unpolluted areas tree branches are covered in pale coloured
lichens camouflage for the paler form (insularia).
n.b. Environmental policies in Europe have reduced air pollution and evolution of the peppered moth is now reversing.
Environmental change: sulphur dioxide pollution kills the lichens and soot (from coal burning) blackens the tree branches.
The moths fly at night to try to find a mate, but, during the day they rest on the branches of trees.
Result: the dark moths are well camouflaged from birds against dark tree branches are many survive to reproduce, but light coloured moths are easily found and predated by birds, few survive to reproduce.
Selective pressure: Predation from birds (and other animals) whilst resting
Evolution: over a number of generations the dark (carbonaria) form of the peppered moth has increased with frequency - the heritable characteristics of the population have changed.

16. How does this cartoon fit in with this topic?
What ideas and key terms are related to this image?

17. Bibliography / Acknowledgments
Jason de Nys