Darwin & Wallace Section
HMS Beagle
What observations did Darwin make on his voyage?
1) Variation in members of same species 2) Plants and animals different at each location 3) Most suited individuals survived
Theory Development
What did Darwin develop to explain his observations?
Theory of evolution by natural selection
Wallace's Work
What did Wallace study and discover?
Warning coloration in species (especially butterflies) and developed theory of speciation
Publication
When did Darwin and Wallace publish their papers together?
1858
Origin of Species
When was "On the Origin of Species" published?
1859
Evolution by Natural Selection
Definition
What is evolution?
The change in frequency of a phenotype in a population over many generations
Theory Components
What are the key points of Darwin's theory?
1) Species show variation 2) Individuals with best characteristics survive 3) These pass to offspring 4) Beneficial traits become more common
Acceptance Issues
Why wasn't evolution immediately accepted?
1) Controversial ideas 2) Challenged religious beliefs 3) Insufficient evidence 4) Mechanism of inheritance unknown
Antibiotic Resistance
Antibiotics
What are antibiotics?
Chemical substances made by fungi/bacteria that affect bacterial cell function/structure
Effectiveness
Why don't antibiotics affect viruses?
Viruses have no cell functions or structures that antibiotics can target
MRSA
What is MRSA?
Methicillin-resistant Staphylococcus aureus - bacteria resistant to methicillin antibiotics
Prevention
How can antibiotic resistance be prevented?
1) Only use when needed 2) Complete full course 3) Don't use for viral infections 4) Reduce use in farming
Evidence of Evolution
Ardi
What are key features of Ardipithecus ramidus (Ardi)?
4.4M years old, found in Ethiopia, climbed trees but walked upright, ape-like big toe
Lucy
What are key features of Australopithecus afarensis (Lucy)?
3.2M years old, arched feet for walking, no ape-like toe, more human-like than Ardi
Turkana Boy
What are key features of Homo erectus (Turkana Boy)?
1.6M years old, human-sized brain, body proportions closer to modern humans
Dating Methods
How are fossils dated?
1) Stratigraphy (rock layers) 2) Carbon-14 dating 3) Study of structural features
Pentadactyl Limb
Definition
What is a pentadactyl limb?
Limb with five digits (fingers or toes)
Distribution
Which groups have pentadactyl limbs?
Mammals, reptiles, and amphibians
Evolution Evidence
Why is the pentadactyl limb evidence for evolution?
Similar bone structure in different species suggests common ancestor
The Three Domains
Traditional Classification
What was Linnaeus' classification system?
Kingdom → Phylum → Class → Order → Family → Genus → Species
Modern System
What are the three domains?
Archaea, Bacteria, Eukaryota
Archaea
What are Archaea?
Primitive bacteria living in extreme environments (hot springs, salt lakes)
Development
Who developed the three-domain system and when?
Carl Woese in 1990
Modern Methods
How are organisms classified today?
Using genetic analysis (DNA/RNA sequences) to determine relationships