Final answer:
The Earth is called a 'lonely living planet' because it is the only known planet to support a vast array of life due to its optimal distance from the sun, suitable atmosphere, and presence of water. The given options do not directly correlate with the factors that contribute to Earth's uniqueness as a living planet. Earth's ability to host endemic species due to geographical isolation and the importance of maintaining atmospheric balance are also pivotal for its status as a 'lonely living planet'. Option d is the correct answer.
Step-by-step explanation:
The Earth is often referred to as a lonely living planet because, to our current knowledge, it uniquely hosts a wide variety of life forms due to its optimal conditions. Factors such as the planet's suitable distance from the sun, which allows for moderate temperatures, and its rich atmosphere that traps heat just enough to sustain liquid water on its surface, contribute to Earth's ability to support life. These conditions have allowed for a diverse ecosystem to flourish, unlike any other known planet in our solar system. Furthermore, Earth's biosphere affects its atmosphere and surface in ways that are observable and indicative of life, setting it apart from other planets and moons where life has not been detected or does not appear to influence the environment on a planetary scale.
Addressing the student's multiple-choice question, given the context provided, the correct option that explains why Earth is called the lonely living planet would be related to Earth's unique supportive conditions for life, making option (d) 'Limited communication and physical isolation' incorrect. Instead, the right conditions for the title likely revolve around Earth being the only known planet with an abundance of water, a suitable atmosphere, and moderate temperatures - factors that aren't captured in any of the options provided. However, based on the closest relation to the provided context and scientific facts, none of the options given directly describe why Earth is considered the lonely living planet.
Geographical Isolation and Endemic Species
Geographical isolation can result in the development of endemic species, which are unique to specific regions because the isolation has prevented gene flow between populations and has driven independent evolution and speciation. Earth's diverse ecosystem also depends on the proper balance of gases in its atmosphere. Increases in greenhouse gases such as CO2 and a decrease in ozone are concerns because they can lead to adverse effects on climate and life, such as global warming and increased ultraviolet radiation. To address these concerns, we must take steps to reduce greenhouse gas emissions, although there are technological, economic, and political challenges involved.