Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial. Today, penguins (which are birds) and
seals (which are mammals) have forelimbs adapted for swimming. What term best describes the relationship of the bones in the forelimbs of penguins and seals, and what term best describes the flippers of penguins and seals?1. analogous, analogous2. analogous , homologous3. homologous , homologous4. homologous , analogous
Answer: The term that best describes the relationship of the bones in the forelimbs of penguins and seals is HOMOLOGOUS and the term that best describes the flippers of penguins and seals is ANALOGOUS. Therefore the correct option is 4.
Explanation:
Charles Darwin proposed his first idea on natural selection using mostly evidence based on anatomical features of the organism. These anatomical similarities are classified into:
- Analogous structures and
- Homologous structures.
ANALOGOUS structures: These indicates that anatomical structures being observed are similar and perform the same function but their is no common ancestry between the two organisms( that is, the two organisms are unrelated species even though they have undergone several changes and adaptation to become more similar).A typical example is the flipper of penguins and seals. The both organism use their flippers for locomotion in water but penguins have common ancestry with birds while seal is with mammals. However, both live in similar environment where flippers is uses for swimming.
HOMOLOGOUS structures: These are anatomical structures from different organism which are similar due to recent common ancestry between organism. Example is the bones in the forelimbs of penguins and seals.
The bones in the forelimbs of penguins and seals are best described as analogous, while the flippers of penguins and seals are homologous.
Analogous structures are structures that are similar in different organisms, even though they are unrelated to each other. For instance, the wings of birds and the fins of a penguin or a fish.
Homologous structures are similar structures in related organisms. Both the penguins and the seals have flippers. Another example is the human arm and the wings of a bat. Both have similar structures internally, but while a human lifts items with their hands, the birds use theirs for flying.
