Origins and Evolution of Life on Earth

These flashcards cover key vocabulary and concepts introduced in the lecture about the origin and evolution of life on Earth, including the geological time scale and the development of early biological molecules.

Eons

The four largest increments of geological time scale.

Multicellularity

The condition of being made up of more than one cell, which allows for greater complexity in organisms.

Precambrian

The era before the Phanerozoic era, characterized primarily by single-celled organisms.

Phanerozoic Era

The era where visible life is abundant, characterized by multicellular organisms.

Cyanobacteria

Photosynthetic bacteria which are important for producing oxygen.

Photosynthesis

The process by which cyanobacteria convert carbon dioxide into glucose using sunlight.

Prokaryotes

Single-celled organisms without a nucleus, including bacteria and archaea.

Organic Molecules

Molecules that contain carbon and are the building blocks of life.

Amino Acids

The building blocks of proteins, which are essential for life.

Montmorillonite

A type of clay suggested to have facilitated the formation of polymers from organic precursors.

Protobionts

Pre-cellular structures that contain organic molecules and have boundaries but are not considered fully alive.

RNA World Hypothesis

The theory that the first self-replicating entities were based on RNA.

Chemical Selection

The process by which certain molecules increase in number due to beneficial traits.

Anaerobic Respiration

A type of respiration that does not require oxygen to produce ATP.

Autotrophs

Organisms that produce their own energy storage molecules, such as through photosynthesis.

Heterotrophs

Organisms that obtain energy from consuming organic molecules from other sources.

Redox Reactions

Chemical reactions involving the transfer of electrons, fundamental in metabolism.

Fossil Record

The history of life documented by fossils, showing the evolution of organisms over time.

Evolutionary Biology

The study of the processes that have led to the diversity of life on Earth.

Mass Extinctions

Significant and rapid decreases in biodiversity, generally involving high percentages of species loss. (5 so far )

Eukaryotes

Organisms made of cells that contain a nucleus, appearing after the rise of oxygen in the atmosphere.