Column X lists evolutionary ideas and scientists who proposed them, and Column Y lists the description of these ideas.

Column X	Column Y
A. Modern synthesis by Julian Huxley	I. A stochastic process where lineages show random genealogical relationships when traced back in time.
B. Phyletic gradualism by Charles Darwin	II. Evolutionary change appears instantaneous between geological sedimentary layers.
C. Punctuated equilibrium by Stephen Jay Gould and Niles Eldredge	III. Synthesis between Mendelian genetics, population genetics, and selection theory.
D. Coalescent model (inspired by) Wright-Fisher model	IV. New species arise by the gradual transformation of ancestral species.

Which one of the following options represents all correct matches between Column X and Column Y?

Correct option is A

Ans. 1. A-iii; B-iv; C-ii; D-i

Let’s carefully break down the matches:

• A. Modern synthesis by Julian Huxley

  • Correct Match: A-iii

    • Explanation: The modern synthesis refers to the integration of Mendelian genetics, population genetics, and natural selection into a unified theory of evolution. This corresponds to Column Y description III (Synthesis between Mendelian genetics, population genetics, and selection theory).

• B. Phyletic gradualism by Charles Darwin

  • Correct Match: B-iv

    • Explanation: Phyletic gradualism suggests that evolutionary change occurs gradually and continuously over long periods of time. This matches Column Y description IV (New species arise by the gradual transformation of ancestral species).

• C. Punctuated equilibrium by Stephen Jay Gould and Niles Eldredge

  • Correct Match: C-ii

    • Explanation: Punctuated equilibrium proposes that species evolve in rapid bursts of change, followed by long periods of stasis (no change). The appearance of evolutionary change being instantaneous between geological layers is a hallmark of this model, matching Column Y description II (Evolutionary change appears instantaneous between geological sedimentary layers).

• D. Coalescent model (inspired by Wright-Fisher model)

  • Correct Match: D-i

    • Explanation: The coalescent model traces the genealogical relationships of genes back to a common ancestor. This model is inherently stochastic and focuses on how lineages relate through time, which corresponds to Column Y description I (A stochastic process where lineages show random genealogical relationships when traced back in time).

Information Booster:

• Modern Synthesis: This is a combination of Darwin's theory of natural selection with Mendelian genetics, population genetics, and selection theory, forming the foundation for our understanding of how evolution works through genetic variation.

• Phyletic Gradualism: Darwin's model of phyletic gradualism suggests that evolution occurs gradually and continuously over time, leading to the gradual transformation of species. This theory contrasts with punctuated equilibrium, which proposes that major changes happen relatively quickly, followed by periods of stasis.

• Punctuated Equilibrium: The theory of punctuated equilibrium proposed by Gould and Eldredge suggests that species evolve in rapid bursts, followed by long periods of little to no evolutionary change. The fossil record shows instantaneous changes between geological sedimentary layers as new species emerge.

• Coalescent Model: The coalescent model is a mathematical approach used to trace genetic lineages back through time. It helps understand how genetic variation has evolved and how populations are related based on shared genetic ancestry.