Overview
This lecture explains why cheetahs are fast, explores the concept of natural selection, and discusses antibiotic resistance as an example of adaptation.
Cheetah Adaptations and Survival
- Cheetahs are the fastest land mammals, reaching acceleration speeds faster than a Ferrari.
- Their speed is crucial for both catching prey and escaping predators like lions and hyenas in Africa.
- Physical adaptations such as a flexible spine and long legs enable their high speed.
- Variation exists among cheetahs, making some faster than others, influencing survival and food acquisition.
Natural Selection
- All organisms compete for resources to survive, leading to competition within and between species.
- Natural selection is the process where individuals best adapted to their environment survive and reproduce.
- Charles Darwin proposed the theory of natural selection in 1859’s "On the Origin of Species."
- Over time, favorable traits become more common in a population, while less adapted traits are phased out.
- Natural selection leads to gradual changes in species and the emergence of new ones.
Genetic Inheritance and Variation
- Traits are passed from one generation to the next through genes.
- Variations within a population give some individuals a survival advantage.
- Scientists now explain natural selection as the selection of favorable genes.
Antibiotic Resistance: An Example of Adaptation
- The discovery of penicillin revolutionized medicine, but some bacteria quickly developed resistance.
- Bacteria with resistance genes survived and reproduced, leading to populations resistant to antibiotics.
- Modern medicine uses antibiotics more cautiously and seeks alternative treatments due to resistance.
Key Terms & Definitions
- Natural Selection — the process where organisms better adapted to the environment survive, reproduce, and pass on their traits.
- Variation — differences between individuals within a species.
- Genes — units of heredity that determine inherited characteristics.
- Antibiotic Resistance — the ability of bacteria to survive and proliferate despite the presence of antibiotics.
- Adaptation — a trait that increases an organism’s chance of survival and reproduction.
Action Items / Next Steps
- Consider ways scientists can develop new treatments for antibiotic-resistant infections.
- Review the example of cheetahs when studying natural selection and adaptation for exams.