Final answer:
Speciation is the process by which new species form, often due to reproductive isolation and environmental factors. Macroevolution is the large-scale evolutionary change over geological time, leading to new species, and can result from accumulated microevolution or significant environmental events.
Step-by-step explanation:
Speciation and Macroevolution
Speciation is the process through which a new species arises. It happens when populations that share a common ancestor become reproductively isolated and evolve different characteristics over time due to various factors like environmental changes, such as geographic barriers including rivers, mountains, or oceans. An example of this is the different species of squirrels on the opposite sides of the Grand Canyon.
Macroevolution is a larger scale of evolutionary changes that occurs over geologic time and is often evident in the fossil record. It may happen through the accumulation of many small changes, known as microevolution, over a long period, or as a result of significant changes in the environment, such as an asteroid impact.
The concept of macroevolution encompasses the broader evolutionary changes that we witness over paleontological time scales, often leading to the emergence of new species and contributing to the diversity of life on Earth as seen in instances like Darwin's finches, which after thousands of years of isolation evolved into separate species due to macroevolutionary changes.