1. Charles Darwin

2. Darwin’s home at Down, near London
Lifeline
Born 1809
Study (Edinburgh and Cambridge)
Voyage of the Beagle
Retired to Down 1842
The Origin of Species 1859
Died 1882
Darwin’s home at Down, near London

3. Darwin’s achievements
Transformed biological science
Both style and content
Still the cornerstone of biology
Now the cutting edge of psychology
Transformed attitudes of humanity to our place in the universe

4. Not just an evolutionist
Not even a biologist to start with
Collected beetles for fun
Studied geology more seriously
Considered himself a geologist throughout the Beagle voyage and for some time after
Famous for working out how coral atolls are formed

5. Natural selection Developed theory in complete isolation
In face of religious opposition
With no knowledge of genetics
With no knowledge of DNA
With no knowledge of plate tectonics
With no observations of natural selection actually occurring

6. Joining the Beagle Voyage
Not paid for 5 years on Beagle.
Actually, he had to pay!
Was lucky to get on
his father opposed him going
Mainly asked because of his class, to keep Captain Fitzroy company
It was the making of him

7. CHARLES DARWIN Video: Who Was Charles Darwin?

8. Galapagos, 1835 Portrayed as a “Eureka” experience.
Actually, was hugely homesick
Did not recognise significance until back in England, 1837.
Worked out theory much later.
First inkling of natural selection in 1838.
Turtles & finches were key evidence
On boat home, ate turtles, dumped shells
Thought finches different species; didn’t even label them properly

12. The Big Idea: Natural Selection
Darwin’s sand walk at Down: a daily thoughtful stroll
He knew about fossils
Collected many for extinct animals
Knew about Lyell’s theory of “evolution” of geology (uniformitarianism)
Read Malthus (an economist) on population and competition for resources.
His ideas developed steadily over 20 years

13. Alfred Russel Wallace Thought of natural selection independently
Wrote to Darwin
Darwin had been working on book
Published a “letter” jointly
It was Darwin who put in the hard years collecting and documenting evidence to support theory

14. Natural Selection
Process of change in populations over many generations
Populations have genetic diversity
Environment exerts ‘selective pressure’ (food, climate, predators, etc.)
Individuals with certain traits survive local environmental conditions
Pass on favourable alleles to offspring

15. Assumptions of Natural Selection
Variation
-All members of a species display a variety of characteristics in their appearance and behavior.
-Variation among individuals is (at least in part) heritable.

16. Assumptions of Natural Selection
2. Competition
number of offspring produced by individuals in a species exceeds the number of offspring that will survive to adulthood

17. Competition

18. Assumptions of Natural Selection
3. Fitness
Some offspring, because of their differences, are better able to adapt to the conditions of the environment than others and be more successful at surviving and reproducing.

21. Assumptions of Natural Selection
4. Adaptation
Individuals with most favourable variations (those who are better at surviving and reproducing) are naturally selected.

25. “Descent with Modification”
Darwin never used the word ‘evolution’ in his book On the Origin of Species
Used the term ‘descent with modification’ instead

26. Natural Selection

27. Artificial Selection
Selective pressure exerted by humans on populations
Improve or modify particular desirable traits
Eg. Selective breeding in farm animals

28. Artificial Selection In food crops
Wheat, corn, rice and veggies have all been selectively bred
Wild mustard plant has been modified to produce broccoli, Brussels sprouts, cabbage and cauliflower
Breed for nutritional value, as well as harvest yield and pest resistance

29. Artificial Selection In food crops:
Wheat, corn, rice and veggies have all been selectively bred
Wild mustard plant has been modified to produce broccoli, Brussels sprouts, cabbage and cauliflower
Breed for nutritional value, as well as harvest yield and pest resistance

30. Designer Dogs How many breeds of dogs are there now? Examples:
What do you get when you cross a Yorkie and a Poodle?
Yorkie-poo

31. Designer Dogs What about a Pug and a Beagle?
Puggle
Or a Siberian Husky and German Sheppard?
Gerberian Shepsky

32. Yorkshire Terrier and Maltese?
Morkie!
Mr. Alex Ander Dickie

33. Consequences of Artificial Selection
In dogs: respiratory problems (bulldogs) and hip dysplasia (labs)
In crops: reduces genetic variation (monoculture)