Zusammenfassung der Ressource
Natural Selection
- Darwin's Theory
- Different organisms in a species have genetic variation
- Individuals best adapted to the
environment are more likely to survive
- Surviving individuals are more likely to breed
- Creating offspring with best adaptations
- The best characteristics are passed on to the next generation
- Controversy
- Inconclusive evidence
- Challenged religious belief of God's creation
- Idea of genes had not been discovered
- Alfred Russel Wallace
- Had similar ideas to Darwin
- Both spent time on islands
- Both produced joint writings
- Modern Biology
- Discovery of genes
- How traits are inherited
- Evolutionary biology
- How organisms have adapted over time
- Evidence
- Fosslis
- Show gradual change in organisms over time
- Can show how species are related
- Pentadactyl Limbs
- Five digits/fingers
- Found in many species
- Formation:
- Casts around soft materials
- Preservation
- In conditions where
decay is not possible
- Glaciers
- Extreme, low temperatures
- Peat bogs
- Extreme acidity
- Mineral Replacement
- Hard parts of organisms
replaced by minerals
- Leave behind rock-like substance after decay
- Examples
- Ardi
- Oldest human fossilised remains
- 4.4 million years old
- Ardipithecus ramidus
- Lucy
- 3.2 million years old
- Australopithecus afarensis
- Leakey
- Most recent discoveries
- 1.6 million years old
- Stone Tools
- More complex tools = bigger human brains
- Basic tools - 2.6 million years ago
- Complex tools - 1.6 million years ago
- Carbon Dating
- Shows when the stone was formed
- Not when the tool was built
- Determine how deep it was buried
- Deeper = older
- Use known dates of other items/fossils from that level
- Compare design to other already dated stone tools
- Incomplete record
- Earlier species were soft-bodied
- Geological activity destroyed some evidence
- Antibiotics
- Antibiotic Resistance
- Bacteria reproduce rapidly
- Mutations arise during reproduction
- Some mutations may be
antibiotic resistance
- This will represent a new resistant strain
- If treated with antibiotics, the
bacteria will survive and reproduce
- No treatment, and no human immunity
- Development is slow and costly
- Must only be prescribed for serious infections
- Patients must complete the full course
- Classification
- 3 domain system
- Proposed by Carl Woese
- Based on chemical analysis
- Archaea - primitive bacteria
- Mostly extremophiles
- Bacteria - true bacteria
- Eukaryota - organisms with complex sub-cellular structures
- Linnaean classification system
- Devised by Carl Linnaeus
- Based on structure and characteristics
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species