Question

Which of the following did not play a significant part in Charles Darwin's theories of evolution? (A) survival of the fittest. (B) natural selection. (C) DNA. (D) adaptation.

Short answer

(C) DNA did not play a significant part in Charles Darwin's theories of evolution, as it was not discovered until after his time.

Step-by-step solution

Analyze the options

Let's analyze each of the options and see how they are related to Darwin's theories. (A) Survival of the fittest: This concept was a core idea in Darwin's theory of evolution. It is the idea that individuals best suited to their environment will survive and reproduce, ensuring the persistence of the species. (B) Natural selection: Natural selection is another key concept in Darwin's theory of evolution. It refers to how certain traits become more widespread in a population because the organisms possessing these traits have an advantage in terms of survival and reproduction. (C) DNA: Deoxyribonucleic acid (DNA) is the carrier of genetic information in organisms. Although DNA was not discovered during the lifetime of Charles Darwin, it served as the molecular basis for the heredity of traits, which is an integral part of the theory of evolution. (D) Adaptation: Adaptations are traits that have evolved through natural selection, leading to better survival and reproduction for the organisms possessing them. This is also a central concept in the theory of evolution.

Identify the option not part of Darwin's theories

Based on the analysis of each option, it is evident that DNA (Option C) did not play a significant part in Charles Darwin's theories of evolution. This is because DNA was not discovered until after Darwin's time, and his theories were not based on a molecular understanding of heredity. The other options are all key concepts in the understanding of evolution as proposed by Charles Darwin. So, the correct answer is: (C) DNA.

Key concepts

Natural Selection

Charles Darwin's theory of evolution is often closely linked with the concept of natural selection. This central idea explains how certain traits within a population become more common. Essentially, organisms that have traits better suited to their environment tend to survive longer and reproduce more successfully. Over time, these beneficial traits become widespread.

Natural selection can be understood through these points:

• Individuals within a species show variation in physical characteristics.
• Some of these traits provide a greater chance of survival than others.
• The advantageous traits can be passed on to the next generation.

This is what gives natural selection its power—over long periods, it can cause populations to change, leading to evolution. It shows how species adapt to their environment, not by chance, but through a rigorous process of selection where only the fittest survive to pass on their traits.

Adaptation

Adaptation is a process by which a species becomes better suited to its environment. It is one of the key mechanisms of evolution and often occurs due to pressures from the environment that favor individuals with traits that enhance their survival.

There are a few things that characterize adaptation:

• Adaptations can be structural, such as changes in physical form or behavior.
• They can also be physiological, involving changes in the internal functions of the organism.
• These changes occur over many generations, driven by natural selection.

By adapting, species can better exploit new niches, avoid predators, or manage to find new sources of food. This enables them to thrive in various environments across the planet. Understanding adaptation helps explain the immense diversity of life and the complex interconnections of ecosystems.

Survival of the Fittest

"Survival of the fittest" is a phrase often associated with Darwin's theory of evolution, even though it was Herbert Spencer who actually coined it. The concept describes the mechanism by which natural selection operates: the "fittest" individuals are the ones most well adapted to their environments.

Here’s how "survival of the fittest" works:

• The term "fittest" refers not necessarily to physical strength but to the ability to survive any changes in the environment.
• It includes those who can gather resources efficiently, avoid predators, or endure adverse conditions.
• Over time, these individuals reproduce and increase the prevalence of advantageous traits in a population.

Ultimately, "survival of the fittest" explains why certain traits become common over generations, guiding evolutionary change and fostering biodiversity. By aligning the concept of fitness with adaptability, it underlines the critical role of environment in shaping species.