1. Introduction to Evolution – Chapter 15
Biology 1

2. Evolutionary Theory Timeline
1735- Carolus Linnaeus, classification
1785- James Hutton
1798-Thomas Malthus
1809- Jean Baptiste Lamarck
1831 to Voyage of the H.M.S. Beagle
1833- Charles Lyell
1858- Alfred Wallace
1859- Charles Darwin

3. James Hutton Geologist
Proposed that the Earth was millions (not thousands) of years old
Based on the processes of rock upheaval (uplift) and weathering

4. Thomas Malthus Economist
Proposed that humans would run out of resources like food and space if the human population numbers continue to grow
If food and space are scarce, there will be competition for them

5. Jean Baptiste Lamarck French naturalist
Proposed one of the first theories about how species change over a period of time (evolution)
In Lamarck’s theory, individuals evolved

6. Lamarck’s Theory Three Principles Tendency Towards Perfection
Innate tendency towards complexity and perfection
Use and Disuse
Organism develops new adaptation by using the structure more
Organism loses an adaption by not using the structure
Inheritance of Acquired Traits
Traits acquired by an organism can be passed on to the next generation

8. Charles Lyell Geologist Published “Principles of Geology”
Also proposed that the Earth is very old
Proposed the forces at work in geology today are the same forces that have shaped the structures throughout time on Earth
This had to take a long time

9. Alfred Wallace Naturalist Independently proposes theory of evolution
Writes Darwin about theory prompting him to publish his theory formed many years before

10. Charles Darwin Born the same day as Abraham Lincoln
Studied theology in college
Became the naturalist
aboard the H.M.S. Beagle
Proposed theory of evolution
based off of observation
from that trip
Published theory in On
the Origin of Species in 1859

11. Voyage of the H.M.S Beagle
Sailed from England
Traveled to
South America
Africa
Australia
New Zealand
Galapagos

13. Voyage of the Beagle (cont)
Darwin studied
Difference within and between species
Living specimens
Fossils
Geology

14. Galapagos Islands Group of islands off the coast of South America
Each island has a unique climate
Darwin observed
Marine iguanas
Tortoises
Finches

16. Darwin’s Theory of Evolution (Natural Selection)
Variation
Individuals naturally vary from each other
Heritability
Variations that are genetically based can be passed on from one generation to the next (although Darwin did not know how)

17. Darwin’s Theory of Evolution (Natural Selection)
Struggle for Existence
Most populations grow past their resources
Organisms within a population must compete for their share
Food
Space
Mates
Other necessities

18. Darwin’s Theory of Evolution (Natural Selection)
Reproductive Advantage
Organisms have adaptations (inherited variations or trait) that make them a good match to their environment (fitness)
Individuals with better fitness survive longer and reproduce more therefore passing on their genes
Future generation have more individuals with the well-fitted adaptation
It is about reproduction not survival!!!

19. Adaptations for Fitness
Survival
Camouflage
Bright coloration
Body Size
Heightened senses
Behavior
Reproduction
Strength
Costly structures

21. Darwin’s Theory of Evolution (Continued)
Artificial Selection
Most fit adaptations are based on human choices
Individuals are bred to pass on desired traits

22. Darwin’s Theory of Evolution (continued)
Descent with Modification
Individuals have
common descent
Evolution over a long
period of time diversifies
species
All species descend from
common ancestor
Cladograms- diagram
showing evolutionary relationships

23. Evidence for Evolution
Fossil Record
Darwin knew fossils represented dead organisms
Also knew that newer organisms were closer to the top
Record showed evidence of change over time

24. Evidence for Evolution (continued)
Geographical Distribution of Living Species (Living and Fossils)
Beaks of Galapagos Finches
Neck Length and Shell Shape for Tortoises
Various Variations for Marine Iguanas
Pattern of Organisms in Similar Environment

25. Evidence for Evolution (continued)
Anatomy: Homologous and Vestigial Body Structures
Homologous
Structures that develop from the same embryonic tissues
Mature forms often have similarities but may look different and have different functions
Vestigial
Structures that no longer have a function for an organism but are still present

26. Homologous Structures

27. Vestigial Structures

28. Evidence for Evolution (continued)
Embryology
Many embryos
look similar to
each other during
development and
develop in similar
ways