Evolution of human appears parallel to the progressive development of brain and language skills. As such, the evolution of individual species in the sequence of their appearance is:

Related Formula

Homologous Organs (Forelimbs of Whales/Bats) arrow Divergent Evolution Analogous Organs arrow Convergent Evolution$\text{Homologous Organs (Forelimbs of Whales/Bats)} \rightarrow \text{Divergent Evolution}\\ \text{Analogous Organs} \rightarrow \text{Convergent Evolution}$

Core Logic

Forelimbs of whales and bats have similar anatomical internal structure (humerus, radius, ulna, carpals, metacarpals) derived from a common ancestor but perform different functions. They are homologous organs representing DIVERGENT evolution, not convergent evolution.

All other options (eyes of octopus/mammals, wings of butterfly/birds, flippers of penguin/dolphins) are analogous organs representing convergent evolution.

Step 1: Conclusion

Forelimbs of whales and bats is an example of divergent evolution.

Pattern Recognition

Sees: "NOT an example of convergent evolution". Shortcut: Look for homologous organs arrow$\rightarrow$ Forelimbs of mammals (whales and bats).

Chapter Mix

Class 12 Biology: Evolution

Related Formula

aligned 65 mya &arrow Extinction of Dinosaurs 500 mya &arrow Invertebrates active 350 mya &arrow Jawless fish evolved 320 mya &arrow Seaweeds and early plants aligned$\begin{aligned} \text{65 mya} &\rightarrow \text{Extinction of Dinosaurs}\\ \text{500 mya} &\rightarrow \text{Invertebrates active}\\ \text{350 mya} &\rightarrow \text{Jawless fish evolved}\\ \text{320 mya} &\rightarrow \text{Seaweeds and early plants} \end{aligned}$

Core Logic

Matching geological time milestones in evolution:

• (A) About 65 mya arrow$\rightarrow$ Dinosaurs suddenly disappeared from the earth (II)
• (B) About 500 mya arrow$\rightarrow$ Invertebrates were formed and became active (IV)
• (C) About 350 mya arrow$\rightarrow$ Jawless fish probably evolved (I)
• (D) About 320 mya arrow$\rightarrow$ Seaweeds and few plants probably existed (III)

Step 1: Result

The correct combination is A(II), B(IV), C(I), D(III).

Pattern Recognition

Sees: "65 mya 500 mya 350 mya 320 mya". Shortcut: 65 mya = Dinosaurs disappearance (A-II); 500 mya = Invertebrates (B-IV).

Chapter Mix

Class 12 Biology: Evolution