Evolution Notes - SBI4U0 Whatisevolution? EVOLUTIONNOTES

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SBI4U0 EVOLUTION NOTES What is evolution? -The changes in the gene pool of a species over time.  These changes are the results of  mutations natural selection  and genetic drift. -All the life changes that have transferred life on earth from its earliest beginnings to the diversity  that characterizes it today.   OR -The process by which an ancestral species could diversify into many descendant species by the  accumulation  of adaptations  to various environments. Darwin's phrase for evolution was "descent with modification". Often populations produce more offspring than the environment can support; in other words, they  often exceed the carrying capacity.  Over-production of offspring leads to intraspecific competition  and survival of the individuals best suited to that particular environment.  This process is known as  natural selection. Within a species, there is genetic variation. Remember that sexual reproduction promotes variation in a species.  Creating gametes by  meiosis provides variation through random assortment.  The fusing of two different gametes leads  to even further variation in the new offspring. Variation in a species can also come about through mutations.  Variation is non-directional, in 
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Evolution Notes - SBI4U0 Whatisevolution? EVOLUTIONNOTES

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