Understanding Human Variations: Analyzing the Passage

The question asks us to fill in the second blank in the given passage. The passage discusses the nature of human beings, starting with their common fixed inherited traits like a developed nervous system, backbones, erect posture, and hair. It then proceeds to talk about what arises from changes to this basic pattern.

Analyzing the Context of Blank (2)

The sentence containing blank (2) is: "Therefore, ________ (2) among human beings arise only in _______ (3) changes of this basic pattern."

The word "Therefore" indicates that this sentence is a consequence or result of the previous statement. The previous statement highlights the common, fixed inherited traits that all humans possess. The sentence we are analyzing talks about what arises from changes in this basic, common pattern.

When there are changes to a common pattern, the result is typically differences or divergences from that pattern. We need a word that describes these differences or divergences among human beings.

Evaluating the Options for Blank (2)

Let's examine the given options for blank (2):

• similarities: This refers to what is common or alike. The passage already stated the common traits. Changes in a pattern lead away from similarity, towards difference. So, "similarities" does not fit the context of arising from changes.
• naturalness: This refers to being natural or occurring in nature. While variations are natural, the word "naturalness" doesn't describe what arises from changes in a pattern in this context.
• sameness: This is synonymous with similarity and contradicts the idea of changes leading to something arising. Changes would reduce sameness.
• variations: This refers to differences or divergences from a standard or common type. Changes in a basic pattern directly lead to variations. This word perfectly fits the context of differences arising among human beings due to changes in the basic inherited pattern.

Selecting the Most Appropriate Word

Based on the analysis, the word that logically follows from "Therefore" and describes what arises from "changes of this basic pattern" is "variations". The sentence then reads: "Therefore, variations among human beings arise only in _______ (3) changes of this basic pattern." This makes sense because variations are the differences that exist between individuals within a species, often stemming from changes or modifications to the inherited traits.

Conclusion

The most appropriate option to fill in blank number 2 is "variations".

Revision Table: Key Concepts

Additional Information: Biological Variation in Humans

Biological variation is the natural difference that exists among individuals of a species. In human beings, this variation is observed in numerous aspects, such as physical characteristics (like height, skin color, hair texture), genetic makeup, susceptibility to diseases, and more.

This variation is crucial for the survival and evolution of the human species. It allows populations to adapt to different environments and changing conditions.

The passage correctly points out that despite the vast commonalities in our fundamental biological makeup (the basic inherited pattern), it is the changes or modifications to this pattern over time and across populations that lead to the observable differences or variations among us. Racial differences, as mentioned in the passage, are just one example of these variations, often based on relatively minor genetic or phenotypic differences.