1. Evolution Recap

2. What is it? Species – can reproduce to produce new generations
Population – number of a species in an area
Trait – distinguishing feature of an animal
Variation – differences in a trait between individuals from:
Mutation
Sex – brothers and sisters rather than clones
Selection
Reproduction
Selection of a variation of a trait that is passed onto the next generation of a species
Variation + Selection + Reproduction = Evolution
Isolated populations + Selection = New Species

3. History of the Idea
Old idea from ancient times animals change over time
Grandfather Darwin – All creatures have one Great Great…. Great Grandmother – little evidence and no reason why – not a scientific theory
Darwin – Natural Selection - Children are variation of parents then Survivors reproduce – But Darwin was upper class, and Evolution supporters were being laughed at by upper class for lack of evidence and reason why – Darwin built his case for 20 years
Wallace – Struggle for Existence – Working class selling stuffed animals to Upper class. Ship got burnt, then in fever of Malaria worked it out. Wrote to Darwin and they “Co-published”
Lamark – Had a wrong reason why – stretching your neck makes it longer, then have sex and your baby will have a longer neck.

4. Evidence Similarities of existing animals – slugs and snails
Fossils (1970 – good, 2009 – excellent)
Feature evolved to do different jobs – hands and wings
Different features evolved to do the same job – jaws and ears
Vestigial Organs – appendix,
Embryos all look the same – we have a tail and gills at 20 days.
DNA – work out who are you parents, then grandparents then their grandparents ….. Traced to an Adam, then back to chimpanzee ancestor, female line tracked back to bacteria. David A – says proven.
8 Years read Human DNA is 2003 – now species are sequenced every few hours to build the complete evolutionary map
Evolution is diseases of Flu and HIV – now accepted
Evolution now in Computer games, and modern products.

6. History of Life 4.5 Ga– earth made 3 Ga – single cell
2.3 Ga – Snowball 1 Oxygen!
0.65 Snowball – multicell
0.53 Eyes – Sex – Cambrian explosion
0.38 Ga land animals
0.23 – 0.06 Ga Dinosaurs

7. How old is that rock? Layer of rock, dated by fossils.
Old ones are at the bottoms
50% Element A decays to element B over 1 G years, and rock has no B then
100 % A – 0% B = 0 yr.
50 % A – 50 % B = 1 Gyr
25 % A - 75% B = 2 Gyr
6.25 % A – 93.75% = 4 Gyr

9. video