Column X Column Y A. Modern synthesis by Julian Huxley I. A stochastic process where lineages show random geneological 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.
A - iii, B - iv, C - ii, D - i
Evolutionary Ideas and Their Descriptions
The question asks us to match different evolutionary concepts and the scientists associated with them (Column X) with their corresponding descriptions (Column Y). Let's analyze each item and its description to find the correct match.
Matching Column X with Column Y
We need to understand the core idea behind each concept listed in Column X and find the best description in Column Y.
- A. Modern synthesis by Julian Huxley: The Modern Synthesis is a 20th-century synthesis of evolutionary biology and genetics. It unified Darwin's theory of evolution by natural selection with Mendelian genetics. It also incorporated ideas from population genetics and other fields. Description III, "Synthesis between Mendelian genetics, population genetics, and selection theory," perfectly matches this concept. So, A matches with III.
- B. Phyletic gradualism by Charles Darwin: Phyletic gradualism is a model of evolution which theorizes that most speciation is slow, uniform, and gradual. This view is based on Darwin's idea that evolutionary change occurs through the accumulation of many small changes over long periods. Description IV, "New species arise by the gradual transformation of ancestral species," accurately describes phyletic gradualism. So, B matches with IV.
- C. Punctuated equilibrium by Stephen Jay Gould and Niles Eldredge: Punctuated equilibrium is a theory in evolutionary biology which proposes that once a species appears in the fossil record, the population will remain stable, showing little evolutionary change for most of its geological history. This state of little or no change is called stasis. When evolutionary change does occur, it is localized in rare, rapid events of branching speciation. In the fossil record, this appears as sudden changes between sedimentary layers, followed by long periods without significant change. Description II, "Evolutionary change appears instantaneous between geological sedimentary layers," aligns with the concept of punctuated equilibrium. So, C matches with II.
- D. Coalescent model (inspired by) Wright-Fisher model: The coalescent theory is a model of how genetic sequences in a population can be traced back to a single common ancestor. It describes the process of genetic drift in a population by looking backwards in time. It is a stochastic process, meaning it involves randomness, and it is related to population genetic models like the Wright-Fisher model. Description I, "A stochastic process where lineages show random genealogical relationships when traced back in time," is a fitting description for the coalescent model. So, D matches with I.
Summary of Matches
Based on the analysis above, the correct matches are:
- A - iii
- B - iv
- C - ii
- D - i
Let's present these matches in a table format for clarity.
| Column X (Evolutionary Idea & Scientist) | Column Y (Description) | Match |
| A. Modern synthesis by Julian Huxley | I. A stochastic process where lineages show random genealogical relationships when traced back in time. | A - iii |
| B. Phyletic gradualism by Charles Darwin | II. Evolutionary change appears instantaneous between geological sedimentary layers. | B - iv |
| C. Punctuated equilibrium by Stephen Jay Gould and Niles Eldredge | III. Synthesis between Mendelian genetics, population genetics, and selection theory. | C - ii |
| D. Coalescent model (inspired by) Wright-Fisher model | IV. New species arise by the gradual transformation of ancestral species. | D - i |
The option that represents all correct matches is A - iii, B - iv, C - ii, D - i.
Important Questions from Evolution and Behavior
Reduction in the frequency of heterozygous genotype with a concomitant increase in the frequency of homozygous genotype, in context of random mating is due to
A founder population has an Aa heterozygous genotype with a frequency of 1, and no individual with either AA or aa genotypes. With repeated self-fertilization, the frequency of AA, Aa and aa after three generations will be:
Many species of birds call at dawn in temperate regions. The phenomenon is referred to as "Dawn Chorus". Several explanations have been proposed for this. Which one of the options is NOT a correct explanation for the occurrence of "Dawn Chorus"?
Which one of the following statements about the molecular clock hypothesis as proposed by Zuckerkandl and Pauling 1962 is CORRECT?
Consider alleles ‘A’ and ‘a’ in a population. The frequency of heterozygotes will be highest when:
