5.4 Evolution5.4.1: Define Evolution—the process of cumulative change in the heritable characteristics of a population.• Macroevolution – the change from one species to another. i.e. – reptiles to birds• Microevolution – the change from one variation within a species to another. i.e. – a Chihuahua and a Great Dane
5.4 Evolution5.4.2: Outline the evidence for evolution provided by the fossil record, selective breeding of domesticated animals and homologous structures.• Homologous vs. Analogous Structures
5.4 Evolution5.4.3: State that populations tend to produce more offspring than the environment can support.
5.4 Evolution5.4.4: Explain that the consequence of the potential overproduction of offspring is a struggle for survival.• Populations tend to grow exponentially, but population sizes tend to remain constant.• More offspring are produced than can be supported, therefore there is a struggle to survive, where some live and some die.
5.4 Evolution5.4.5: State that the members of a species show variation.
5.4 Evolution5.4.6: Explain how sexual reproduction promotes variation in a species.• So…how does it? (review last unit)
5.4 Evolution5.4.7 Explain how natural selection leads to evolution• The Darwin–Wallace theory is accepted by most as the origin of ideas about evolution by means of natural selection
5.4 Evolution• Since organism’s traits vary, some organisms are more adapted to survival than others.• When there is a struggle to survive those with favorable traits tend to survive long enough to pass them on.• Those that have less favorable traits die before being able to pass the traits on.
5.4 Evolution• There is evidence that the traits of populations change over time in relation to changes in their environment.• However, these recently observed changes are relatively small.• These observations do not prove that the different species evolved from other species. Evolution is simply a theory. There are other theories as well.
5.4 EvolutionTwo useful terms for discussion:• Micro-Evolution – changes within a species due to natural selection in response to environmental changes. Observed. Scientific fact.• Macro-Evolution – change from one species to another species through natural selection. Has not been observed. Still remains a theory.
5.4 Evolution5.4.8: Explain two examples of evolution in response to environmental change; one must be multiple antibiotic resistance in bacteria.-Assignment in Moodle