Question

Which observations are examples of homologies? O The skin flaps for gliding that evolved separately in sugar gliders and flying squirrels help them use similar habitat niches. O The Pax6 gene in vertebrates and the eyeless gene in flies have similar sequences, and both regulate embryonic eye development. The bones that support the wings of birds, pterosaurs, and bats are arranged in the same order in each animal. The pharyngeal arches found in all vertebrate embryos develop into gill supports in fish and throat structures in mammals. The ability to fly using elongated wings developed independently in the lineages that led to birds, pterosaurs, and bats.

Answer 1

• Homologous structures are the same structures developed along different directions due to adaptations
• Homologies have same structure
• Homologies indicates common ancestry
• Homologies contributes to divergent evolution.

   so examples of homologies are:

1.    The pax6 gene in vertebrates and the eyeless gene in flies have similar sequences, and both regulate embryonic eye development ( because they have similar sequences,it indicate same structure or homologies)
2. The bones that support the wings of birds,pterosaurs and bats are arranged in same order in each animal.(they are in same order in each animal .so same structures which indicates homologies)
3. The pharyngeal arches found in all vertebrate embryos develop into gill supports in fish and throat structures in mammals(because they are same stuctures developed for different finction,so homologies)

   Not homologies are: (Analogies - different strucures)

1. The skin flaps for gliding that evolved separately in sugar gliders and flying squirrels help them use similar habitat niches (they are different structures that evolved separately for same function )
2. The ability to fly using elongated wings developed independently in the lineages that led to birds,pterosaurs and bats. (they are different structures which are not anatomically similar though they perform similar functions)