What process is defined as evolution of a trait or a species into another over a period of time?

What process is defined as evolution of a trait or a species into another over a period of time?

• A. Gradualism
• B. Cladogenesis
• C. Parapatric speciation
• D. Anagenesis

Answer: (D)

Anagenesis is evolution within a single lineage where accumulated changes over time transform one species into a different form without any branching. This directly matches the idea of a trait or a species evolving into another along the same line over time, rather than splitting into multiple lineages. Cladogenesis, in contrast, involves a lineage dividing into two or more lineages. Gradualism describes the tempo of change (slow, steady) rather than the pattern of lineage transformation, and parapatric speciation refers to speciation along a geographic gradient with limited gene flow. So the process described is anagenesis.

Anagenesis is evolution within a single lineage where accumulated changes over time transform one species into a different form without any branching. This directly matches the idea of a trait or a species evolving into another along the same line over time, rather than splitting into multiple lineages. Cladogenesis, in contrast, involves a lineage dividing into two or more lineages. Gradualism describes the tempo of change (slow, steady) rather than the pattern of lineage transformation, and parapatric speciation refers to speciation along a geographic gradient with limited gene flow. So the process described is anagenesis.