Lecture 1

What were the key creations on Day 1 of the Genesis creation story?

The creation of light and the separation of light from darkness.

How old do geologists believe the Earth is?

Approximately 4.6 billion years.

What significant event occurred about 3.5 billion years ago?

The first fossils appeared, marking the origin of life.

During which geological era did plants first invade land?

Plants and fungi colonized land around 470 million years ago.

What is the significance of oxygen production about 2.3 billion years ago?

It significantly changed the atmosphere and allowed for the evolution of more complex life forms.

What are the five characteristics that define life?

1. Life uses energy; 2. Organisms consist of cells; 3. Living organisms contain and process information; 4. Life can replicate itself; 5. Life evolves.

What was the outcome of the Miller-Urey experiment?

It demonstrated that complex organic molecules, such as amino acids, could be synthesized abiotically.

Why is the presence of oxygen (O2) a hindrance to abiotic organic molecule formation?

Oxygen attacks chemical bonds and extracts electrons, preventing the formation of complex molecules.

What role do clays play in the origin of life?

Clays may have acted as gathering grounds to concentrate organic compounds and facilitate polymerization reactions.

What are protobionts and why are they significant in the origin of life?

Protobionts are spherical structures formed by macromolecules, and they represent an early step towards the organization of life into cells.

What is a reducing environment in the context of early Earth?

An environment with very little free oxygen (O2) where electron-adding chemical reactions predominated.

When did humans first appear according to the geological time scale?

Humans appeared roughly 200,000 years ago.

What was the composition of the early Earth's atmosphere after it cooled?

It consisted of water vapor, carbon-dioxide (CO2), carbon monoxide (CO), nitrogen (N2), methane (CH4), and ammonia (NH3).

How long did it take for the Earth to cool after its formation?

About 600 million years.

What process is responsible for the formation of the Earth?

The Earth formed through the process of accretion, where dust and gas in a protoplanetary disk came together over time.

What is the significance of the Cambrian explosion?

The Cambrian explosion, occurring approximately 541 million years ago, marks a rapid diversification of life and the appearance of most major groups of animals.

What were stromatolites and their importance in Earth's history?

Stromatolites are layered structures created by the activity of cyanobacteria, and they provide some of the oldest evidence of life on Earth.

What is the Faint Young Sun Paradox?

The Faint Young Sun Paradox refers to the geological evidence that suggests early Earth had liquid water despite a weaker Sun that should have resulted in frozen conditions.

What describes the concept of natural selection?

Natural selection is the process in which organisms better adapted to their environment tend to survive and produce more offspring.

What event is thought to have contributed to the mass extinction at the end of the Cretaceous period?

The impact of a large asteroid or comet is widely believed to have caused the mass extinction event 66 million years ago, leading to the demise of the dinosaurs.

How did photosynthesis change Earth's atmosphere?

Photosynthesis by cyanobacteria introduced oxygen into the atmosphere, leading to the Great Oxidation Event and significant environmental changes.

What is endosymbiotic theory?

Endosymbiotic theory proposes that eukaryotic cells evolved from symbiotic relationships between prokaryotic cells, explaining the origin of mitochondria and chloroplasts.

What is the significance of genetic variation in evolution?

Genetic variation is crucial for evolution as it provides the raw material for natural selection to act upon, helping populations adapt to changing environments.

What is the geological time scale?

The geological time scale is a system used by geologists and paleontologists to describe the timing and relationships of events in Earth's history.