What is the primary difference between microevolution and macroevolution?

• A. Microevolution is driven by natural selection, while macroevolution is driven by genetic drift.
• B. Microevolution occurs over long periods, whereas macroevolution happens quickly.
• C. Microevolution affects large populations, whereas macroevolution affects small populations.
• D. Microevolution refers to changes within a species, while macroevolution involves the formation of new species.

Answer: (D)

Verified step by step guidance

1. Begin by understanding the definitions of microevolution and macroevolution. Microevolution refers to small-scale changes within a species, such as changes in allele frequencies over time. Macroevolution, on the other hand, involves larger-scale changes that can lead to the formation of new species.
2. Consider the processes involved in microevolution. These include mechanisms like natural selection, genetic drift, mutation, and gene flow, which can lead to variations within a species.
3. Examine the processes involved in macroevolution. This typically involves speciation, where genetic changes accumulate over time, leading to the emergence of new species. This can occur through mechanisms such as reproductive isolation and divergent evolution.
4. Differentiate between the time scales of microevolution and macroevolution. Microevolution occurs over shorter time scales and can be observed within a few generations, while macroevolution occurs over much longer periods, often spanning thousands to millions of years.
5. Reflect on the scope of impact. Microevolution affects populations within a species, leading to adaptations and variations. Macroevolution impacts broader taxonomic groups, resulting in the diversification of life forms and the emergence of new species.