Chapter 5 Online Study Guide

The age of the Earth is estimated to be approximately 4.7 billion years old. This estimation is based on various scientific methods, such as radiometric dating of rocks and minerals, which provide evidence for the age of the Earth. These methods involve measuring the decay of radioactive isotopes in rocks and minerals to determine their age. Through these techniques, scientists have established that the Earth formed around 4.6 billion years ago, and since then, it has undergone various geological processes and changes. Therefore, the correct answer is 4.7 billion years old.

Cyanobacteria is credited with creating an oxygenated atmosphere. Cyanobacteria are photosynthetic bacteria that were one of the first organisms to evolve the ability to produce oxygen through photosynthesis. They played a crucial role in the history of the Earth by releasing oxygen into the atmosphere, which eventually led to the development of an oxygen-rich atmosphere that allowed for the evolution of more complex life forms.

A species' fundamental niche refers to the complete range of environmental conditions and available resources that it could potentially utilize if there were no other species competing for the same resources. This includes physical, chemical, and biological factors that could support the species' survival and reproduction. The fundamental niche represents the theoretical capabilities of a species in its habitat, without any limitations imposed by interspecific competition.

Water boils at 212 F. This is the boiling point of water at sea level. At this temperature, water changes from a liquid to a gas, forming steam.

The answer "2 seconds" suggests that our species evolved very close to midnight, indicating that the evolution of our species occurred relatively recently in the grand scheme of time. This implies that the development of humans as a species is a relatively recent event in the timeline of Earth's existence.

Stabilizing natural selection is the type that tends to eliminate individuals on both ends of the genetic spectrum and favor individuals with an average genetic makeup. This type of selection occurs when the environment favors individuals with intermediate traits, leading to a reduction in the extremes of the trait distribution. As a result, individuals with extreme or unusual traits are less likely to survive and reproduce, while individuals with average traits have a higher fitness and are more likely to pass on their genes to the next generation.

Adaptive radiation refers to the period following a mass extinction where numerous new species evolve over several million years to fill new or vacated ecological roles or niches in changed environments. This process occurs when a few surviving species rapidly diversify and adapt to exploit available resources and habitats. It results in the emergence of a wide range of new species with different characteristics and adaptations, allowing them to occupy various ecological niches. This phenomenon is driven by natural selection and can lead to the formation of diverse and specialized species communities.

Genetic drift is the name of the phenomenon described in the question. It refers to the random changes in the genetic composition of a small population due to chance events. In the example given, the difference in the number of heads in the coin flips is attributed to genetic drift because it is unlikely to occur by chance in a larger population. Genetic drift can have significant effects on the genetic makeup of a population over time, especially in small populations where chance events can have a greater impact.