1. Descent with modification
Evolution
Descent with modification

3. I. Biological Evolution = observable fact
A. Change in species over time
B. On-going Process of change

4. II. One Mechanism for evolution
(One way evolution happens)
A. Natural Selection – Requires
1. Genetic diversity-not all clones
2. some genes better than others
3. better genes more common in next generation

5. III. Pre-Darwin Ideas A. Carolus Linnaeus (1707-1778)
1. Binomial Nomenclature Genus species
2. grouped organisms
3. K P C O F G S
4. Kingdom, phylum, class, order, family, genus, species
5. now we have added Domains

6. B. Stratification –
1. rock made in layers
2. oldest at bottom
3. so oldest fossils at bottom
4. fossils change over time so they…
evolved
5. species appear and disappear

7. C. Lamarck ( )
1. first to connect evolution to environment
2. species change due to effort or
- use and disuse
3. can pass on traits gained by effort
….he was wrong….
………………………………he needed to meet Mendel

9. III. Darwin’s Contemporaries
A. Charles Lyell ( 1797 – 1875)
1. Geologist
2. Theory of Uniformity
3. Natural processes we see today …
worked the same way in the past
4. The rate of stays the same
5. contradicted young earth theory….
said Earth is more than 7,000 years old

10. C. Alfred Wallace ( )
1. first to publish Natural Selection as a mechanism for evolution
2. ideas nearly identical to Darwin’s
D. Charles Darwin ( 1809 – 1882)
1. Origin of Species
2. extensive evidence of
natural selection
3. Lylle, Darwin & Wallace
convinced most scientists with in 10 years

11. IV. Darwin’s main observations/Inferences
Observations in blue
Followed by associated Inference
Inferences in yellow

12. A. Artificial selection: selective breeding
can produce visible change over a life-time
A. If artificial selection can make change….
then natural selection could make major change given enough time
* Lyell suggested a time line of millions of years

13. B. Organisms produce more offspring than can survive
B. Survival is not random, some better than others

14. C. members of a population have different genetic traits
those with best traits are more likely to survive
So good genes build up in population…
Genetic make-up of population ∆ over time =
Evolution!

16. VI. Natural Selection Vocab.
A. Fitness:
ability to pass on its genes
1. survive
2. mate
3. fertile offspring live to reproduce
B. Adaptation: inherited traits that improve fitness in a given environment
1. individuals can NOT adapt its genetic!!
2. only populations adapt over generations

17. VIII. Main Branches of Evidence
A. Direct observation – species change over time
1. Bacteria develop antibiotic resistance

19. 2. Weeds develop resistance to roundup
Figure 1. Number of weed species with glyphosate resistant populations and number of states with glyphosate-resistant weed populations.
Source: Heap, 2009.

21. 3. Grant’s finch research
a. recorded beak depth of all finches on an island over 30 years

22. B. Homology: similarities resulting from
common ancestor
1. Homologous Structures
a. anatomical features
b. same underlying structure
c. may have adapted to different function

23. d. embryo homology may be lost in adult
1. pharyngeal arches – all chordates
2. post anal tail – all chordates

24. e. Chordate limbs : same bones just different shape due to different function of appendage

25. F. Neck bones Mammal neck bones =7 Bird neck bones 13-25
Giraffe neck vertebrae are each elongated…
No new bones added
Birds with short neck have curve in neck vertebrae…
not fewer vertebrae

28. 2. Vestigial Structures : inherited from ancestor but no longer used
a. explains presence of useless structures
b. pelvic girdle & femur in whale & snake

29. 3. molecular homologies: same DNA/ protein
a. all organisms homologous DNA structure
b. Many homologous DNA genes
1. some have developed a new function
2. some still same function
a. genes for ribosome subunits homologous between humans and bacteria
3. some genes vestigial

30. C. Fossil Record
A. document formation of new species by sequential fossils

31. VII. Theory of Evolution
A. speciation – one species branches into 2 new species (ancestral species gone)
B. Adaptive radiation –1 species gives rise to many species (common after mass extinctions)
1. individuals disperse to new environments
2. adapting to new environment causes them to change

32. C. Universal Common Ancestor – all started from some single celled organisms
1. ‘the unity of life’
2. universal genetic code DNA, RNA
3. shared genes (homeotic genes)
4. Semiconservative replication
5. transcription/translation (Met)
6. shared proteins(DNA and RNA polymerase)