Evolution: Charles Darwin

Evolution: Charles Darwin

1. Darwin made 4 observations

   • Living organisms produce far more offspring than can possible survive to adulthood
     • The offspring have variations in their characteristics that are different to the parents
       • Some variations will lead to greater survival advantages than others
         • Those individuals with the better variations will generally tend to survive & produce more successful offspring

2. Deductions from his observations

   • There is competition for survival
     • Individuals with chareristics that best adapt them for their environment are most lily to survive and reproduce
       • If these characteristics can be inherited then the organism will pass the characteristics on to their offspring
         • Gradually the species would become increasingly better adapted to its environment

3. Natural Selection

   • The sorting of "good" from "not good" individuals by their environment is what DArwin termed natural selection
   • Individuals show variation in their characteristics due to difference in their alleles
   • There is constant struggle for survival due to disease, competition and predators
   • Individuals with better adaptions will pass on the alleles that pass on the adaptations

4. Reactions to Darwin's Theory

   • Face high controversy when first release and was the centre of international debate
   • There was opposition because it conflicted with religious beliefs of how life began
   • Was accepted over time as there was more evidence to support his theory and very little to disprove it
   • More scientists proved Darwin to be right thus more accepted his theory as a scientific explanation.