According to the most accepted scientific hypothesis about the origin of two new species from a single common ancestor, most new species arise when
a. Many mutations occur
b. Populations of the ancestral species are isolated from one another
c. There is no natural selection
d. A supernatural creator decides that two new species would be preferable to the old one
e. The ancestral species decides to evolve

Verified step by step guidance

1. Step 1: Understand the concept of speciation. Speciation is the process by which new species arise from a common ancestor. This typically involves the splitting of a single population into two or more genetically distinct groups that can no longer interbreed.
2. Step 2: Recognize the role of isolation in speciation. One of the most widely accepted mechanisms for speciation is allopatric speciation, where populations of the same species become geographically isolated. This isolation prevents gene flow between the populations.
3. Step 3: Consider the role of genetic divergence. Once populations are isolated, genetic differences accumulate over time due to mutations, natural selection, and genetic drift. These differences can lead to the development of reproductive barriers.
4. Step 4: Eliminate incorrect options. For example, options like 'many mutations occur' (a) and 'the ancestral species decides to evolve' (e) are not scientifically accurate explanations for speciation. Similarly, 'a supernatural creator decides' (d) is not a scientific hypothesis.
5. Step 5: Identify the correct answer. The most accepted scientific hypothesis is that speciation occurs when populations of the ancestral species are isolated from one another (b), allowing genetic divergence to occur.

Key Concepts

Speciation

Speciation is the evolutionary process by which populations evolve to become distinct species. It often occurs when populations of a single species become isolated from one another, leading to genetic divergence due to different environmental pressures or mutations. This concept is crucial for understanding how new species arise from a common ancestor.

Isolation Mechanisms

Isolation mechanisms are factors that prevent interbreeding between populations, leading to speciation. These can be geographic, such as mountains or rivers, or reproductive, such as differences in mating behaviors or timing. Understanding these mechanisms is essential for grasping how populations can evolve independently and form new species.

Natural Selection

Natural selection is a fundamental mechanism of evolution where individuals with advantageous traits are more likely to survive and reproduce. This process drives adaptation and can lead to the emergence of new species when populations are subjected to different selective pressures. Recognizing the role of natural selection is vital for understanding the dynamics of speciation.