Evolution

Evolution

1. Variation

   • Intraspecific variation is variation within a species. Interspecific variation is variation between species.
   • Continuous variation: Mass, height, length
     • Discontinuous variation: Sex, blood group, colour, shape
   • Genetic factors
     • Different species have different genes
       • Same species, same genes but different version
     • Inherit gene from parents, variation caused by genetic factor is inherited
   • Environmental
     • Differences in the environment: climate, food, lifestyle
     • Accents, piercings
   • Both (genetic and environmental)
     • Height: diet and nutrition contribute as well as inheritance
     • Flagellum: grow in certain environments, if metal ions are present

2. Adaptions

   • Increases the organisms chances of survival and reproduction and also the chances of its offspring reproducing successfully.
     • Adaptation develop because of natural selection
     • Best adapted individuals are more likely to survive and reproduce, passing adaptations to their offspring.
   • Behavioural
     • Ways an organism acts that increase its chance of survival.
   • Physiological
     • Processes inside an organism's body that increase its chance of survival
   • Anatomical
     • Structural features of an organism's body that increases its chance of survival

3. Theory of evolution

   • Darwins theory
     • Individuals within a population show variation in their phenotypes.
     • Predation, disease and competition create a struggle for survival
     • Individuals with better adaption survive longer
     • Number of individuals with the advantageous adaption increases
     • Over generation it leads to evolution
   • Speciation
     • When populations of the same species evolve to become so different that they can't breed to produce fertile offspring
   • Evidence to support evolution
     • Fossil record evidence
     • DNA evidence and common ancestors
     • Molecular evidence such as proteins
   • Resistance to antibiotics and pesticides
     • By natural selection. There is a variation in a population of bacteria/pests. Genetic mutation make some bacteria/pests resistant to an antibiotic/pesticide. Some will survive and pass genes on generations
       • Infections caused by antibiotic resistant bacteria are harder to treat.
       • Crop infestations with pesticide resistant pest are harder to control.
         • Disease carrying pest become pesticide resistant, disease will be harder to control