Question

a student argues that being separated geographically is the only way for speciation to occur. why is he wrong?
speciation does not result from adaptive radiation.
speciation does not usually rely on geographic isolation.
speciation can occur from biological forces as well.
speciation can occur from variation as well.

Explanation:

1. Analyze Option 1: Adaptive radiation is a process that can lead to speciation (e.g., Darwin's finches), so this is incorrect.
2. Analyze Option 2: Speciation often can rely on geographic isolation (allopatric speciation is common), so this is incorrect.
3. Analyze Option 3: Speciation can occur due to biological forces like reproductive isolation (sympatric speciation, e.g., polyploidy in plants) without geographic separation. This explains why the student is wrong as speciation isn't only via geographic separation.
4. Analyze Option 4: Variation is a part of evolution but not a direct explanation of why geographic separation isn't the only way for speciation. Biological forces (like reproductive isolation) are more relevant.

Answer:

C. Speciation can occur from biological forces as well.