The question asks for the most accurate definition of evolution according to the Modern Synthetic Theory. This theory integrates Mendelian genetics with Darwinian natural selection, focusing on changes within populations over time.
A) Gene (allele) frequency across successive generations. This is the most accurate definition of evolution according to the Modern Synthetic Theory, as it emphasizes the genetic basis of evolutionary change within a population over time.
The question describes the human vermiform appendix as an organ that was functional and larger in ancestors but is now reduced and largely non-functional. We need to identify the biological term that best describes such an organ.
B) Vestigial organ — The human vermiform appendix is a classic example of a vestigial organ. It is a structure that has lost its original function over the course of evolution and is typically reduced in size compared to its functional form in ancestral species. In herbivorous ancestors, it likely played a role in digestion, but with dietary changes in human evolution, its function diminished.
The question asks to identify the scientists who independently proposed the hypothesis that life originated from non-living organic and inorganic molecules through a gradual process of chemical evolution on early Earth. This concept is widely known as the Oparin-Haldane hypothesis.
Correct Option: C) A. I. Oparin and J. B. S. Haldane independently proposed the hypothesis that life originated from non-living organic and inorganic molecules through a gradual process of chemical evolution on early Earth. This is famously known as the Oparin-Haldane hypothesis of abiogenesis.
The question describes a classic evolutionary phenomenon observed in England during the Industrial Revolution, where environmental changes (soot pollution) led to a shift in the dominant phenotype of peppered moths. This scenario is a direct example of natural selection driven by environmental pressures.
A) Industrial melanism (natural selection in action) — This term perfectly describes the observed phenomenon where the increase in dark-coloured moths was a direct result of environmental changes caused by industrial pollution, leading to natural selection favoring the melanic form.
The question describes a scenario where a physical barrier separates two populations of a species, preventing gene flow and eventually leading to the formation of new species. We need to identify the specific evolutionary process that matches this description.
Correct Option: B) Allopatric speciation is the process where new species arise due to geographical isolation preventing gene flow between populations. This matches the description provided in the question.
The question describes a scenario where a single ancestral species diversifies into multiple new species, each adapted to different environmental niches, specifically different food sources, as seen in Darwin's finches. This process is a classic example of a specific evolutionary phenomenon.
B) Adaptive radiation — This term precisely describes the process where a single ancestral species rapidly diversifies into many new species, each adapted to different ecological niches, often following colonization of a new environment with available resources, as exemplified by Darwin's finches on the Galapagos Islands.