[Campbell Biology P.586] Based on Figure 25.14, how many speciation and extinction events oc... | Practice Question

Based on Figure 25.14, how many speciation and extinction events occurred for Lineage A and Lineage B, respectively, during the period from 2 million years ago to time 0?

  • A: Lineage A: 0 speciation, 3 extinction; Lineage B: 4 speciation, 0 extinction.
  • B: Lineage A: 1 speciation, 2 extinction; Lineage B: 3 speciation, 1 extinction.
  • C: Lineage A: 0 speciation, 1 extinction; Lineage B: 8 speciation, 0 extinction.
  • D: Lineage A: 3 speciation, 0 extinction; Lineage B: 0 speciation, 3 extinction.

Explanation

For Lineage A, starting with 4 species at 2 million years ago and ending with 1 species at time 0, there are no new branches formed 0 speciation but three dagger symbols † indicating extinction events. For Lineage B, starting with 4 species at 2 million years ago and ending with 8 species at time 0, there are 4 new branches formed through splitting 4 speciation and no dagger symbols, indicating 0 extinction events.