Question

Despite their striking morphological similarity to each other, Old World and New World vultures are not phylogenetically related. Old World vultures are most closely related to eagles, while New World vultures are most closely related to storks. The morphological similarity between Old World and New World vultures is an example of ____________.

• A. adaptive radiation
• B. cladogenesis
• C. divergent evolution
• D. convergent evolution

Hint:

Check whether the two lineages are close relatives, which would suggest shared ancestry, or distant relatives that ended up looking alike because of a similar lifestyle.

Answer 1

The Correct Option is D

The question tells us two things: the vultures look alike, and they are not close relatives, since Old World vultures sit with eagles and New World vultures sit with storks on the bird family tree. We need the term for lineages that resemble each other without sharing recent ancestry. Let's check every option.

1. Adaptive radiation: This happens when one ancestor quickly splits into many different species that fill many different niches, like Darwin's finches. Here we start from two separate lineages, not one radiating ancestor, so this term does not fit.
2. Cladogenesis: This is just the general term for a lineage splitting into two. It says nothing about why two unrelated lineages would end up looking similar, so it does not explain the pattern described.
3. Divergent evolution: This describes related species drifting apart in appearance from a shared ancestor. The vultures are doing the opposite, converging in looks despite not sharing a recent ancestor, so this is wrong.
4. Convergent evolution: This is exactly what happens when unrelated lineages independently evolve similar traits because they face similar pressures, here, a scavenging lifestyle. This fits the vulture case perfectly.

Since both vulture groups evolved their look independently while filling the same scavenger role, the answer is convergent evolution.

Let's summarize:

• Shared ancestry gives you divergent evolution or adaptive radiation.
• Shared lifestyle without shared ancestry gives you convergent evolution.

So Old World and New World vultures looking alike is a case of convergent evolution.