As a mechanism of evolution, natural selection can be most closely equated with UNEQUAL REPRODUCTIVE SUCCESS.
Mechanism of evolution refers to micro-evolution that involves mutation, gene flow and natural selection. Unequal reproductive success is also related to other processes of micro evolution such as natural selection. The organisms that can reproduce unequally and survive even in adverse condition, increase in numbers.
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<span>When a farmer stops cultivating farmland and abandons
it, the growth of wild grasses and weeds can be considered secondary succession
because of the presence of the existing soil. Secondary succession occurs in ecosystem
when soil have been disturbed or disrupted by humans such in a way of farming. Furthermore, the reason why it cannot be
categorize as primary succession because primary succession only occurs in
essentially lifeless areas, where soil is not capable of sustaining life. Specifically,
this is called old-field succession where wild grasses and weeds represents a new
plant species to colonize a bare soil after the farmer abandon the farmland.</span>