Question 22 Read the following passage and answer the question given below.
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Read the following passage and answer the question given below.
Scientists are interested in understanding whether the ability to fly in birds evolved just once or multiple times. There are over 10,000 species of birds, and around half of them can fly. Among these flying birds, some have developed similar flying abilities independently. To determine if flight evolved just once or multiple times, researchers examine the characteristics of different bird groups.
Recent studies have shown that certain groups of birds evolved their flight independently from each other. This challenges the idea that flight evolved only once from a common ancestor. While many flying birds share similar adaptations for flight, such as wings and hollow bones, they also exhibit differences in other characteristics.
For example, the evolution of flight in birds like pigeons and hummingbirds occurred separately. Despite both these birds being capable of flight, they have distinct differences in their body structures, behaviours, and habitats. Further research into the genetic and anatomical features of flying birds will help scientists understand how flight evolved independently in different groups of birds.
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Show answer & explanation
The passage explicitly provides pigeons and hummingbirds as examples of birds whose flight evolved independently.
Step-by-step Derivation:
Step 1: Look at paragraph 3: 'For example, the evolution of flight in birds like pigeons and hummingbirds occurred separately.'