The Origin and Evolution of the Marine Environment (MSCI *112)

These flashcards cover key vocabulary terms and concepts from the lecture on the origin and evolution of life, including important definitions, hypotheses, and theories.

Universal Tree of Life

A hierarchical structure depicting the relationships among all organisms based on genetic similarities.

Microorganisms

Mostly single-celled organisms, including bacteria, archaea, and some eukaryotes, that occupy diverse environments.

Extremophiles

Microbes that thrive in extreme conditions intolerable to most life forms.

Acidophiles

Organisms that can tolerate highly acidic environments.

Thermophiles

Organisms that thrive at very high temperatures.

Halophiles

Organisms that can survive in environments with high salt concentrations.

Anaerobes

Microbes that can live without oxygen.

Abiogenesis

The process of life arising naturally from non-living matter.

Biological activity

The activities performed by living organisms, including metabolism and reproduction.

Panspermia

The hypothesis that life exists throughout the universe and is distributed by meteoroids, asteroids, comets, and planetoids.

Fossil stromatolites

Layered structures formed by the activity of microorganisms, found as old as 3.5 billion years.

Miller-Urey Experiment

An experiment that simulated early Earth conditions to test the origin of organic compounds.

Primordial soup

A mixture of organic molecules in water from which life is thought to have originated.

Photosynthesis

The process by which green plants and some organisms use sunlight to synthesize foods from carbon dioxide and water.

Microfossils

Fossilized remains of microscopic organisms.

Metabolic processes

The biochemical reactions that transform nutrients into energy and cellular components.

Organic monomers

The building blocks of organic molecules, such as amino acids and nucleotides.

Self-replication

The ability of a living organism to reproduce on its own.

Self-regulation

The capacity of living organisms to maintain internal stability.

Eukaryotes

Organisms with complex cells that have membrane-bound nuclei.

Protocell

A simple version of a cell, hypothesized to be a precursor to true living cells.

Proteinoids

Synthetic polymers formed from amino acids that exhibit some properties of proteins.

Chemosynthesis

The process of converting carbon-containing molecules into organic matter using the oxidation of inorganic molecules, instead of sunlight.

Graphite and Zircon

Minerals used to indicate ancient biological activity based on carbon isotope ratios.

Nucleobases

The building blocks of RNA; include Guanine, Adenine, Uracil, and Cytosine.

RNA World Hypothesis

The theory that RNA was the first molecule capable of self-replication and catalyzing biological reactions.

Microbes

A comprehensive term for microorganisms including bacteria, archaea, and some eukaryotes.

Universal ancestor

The common ancestor from which all life on Earth descended.

Mineral precipitation

The process by which dissolved minerals solidify from a solution.

Chain of Being

A hierarchical structure of all forms of life, from simplest to most complex, proposed by Aristotle.

Mesozoic Era

The geological era that is divided into the Triassic, Jurassic, and Cretaceous periods.

Precambrian Era

The age of the Earth prior to the Cambrian period, encompassing the Hadean, Archean, and Proterozoic eons.

Evolution of cells with nucleus

The transition in the history of life from prokaryotic cells to eukaryotic cells.

Cambrian explosion

A significant event around 541 million years ago marked by a sudden increase in the diversity of life.

Milankovitch cycles

Long-term variations in the Earth's orbit and tilt, influencing climate and glacial cycles.

Phanerozoic Eon

The current eon in the geological timescale, beginning with the Cambrian period and encompassing significant evolutionary events.

Endosymbiotic theory

The theory suggesting that some organelles in eukaryotic cells originated as symbiotic bacteria.

Viruses

Microscopic infectious agents that can only replicate inside living cells.

Convergent evolution

The independent evolution of similar traits in species of different lineages.

Genetic drift

A mechanism of evolution that involves random changes in allele frequencies.

Natural selection

The process where organisms better adapted to their environment tend to survive and produce more offspring.

Fossil record

The total number of fossils that have been discovered and the information derived from them.

Homologous structures

Anatomical features in different species that share a common ancestry.

Adaptive radiation

The rapid evolution of diversely adapted species from a common ancestor.

Transitional fossils

Fossils that exhibit traits common to both an ancestral group and its derived descendant group.

Biodiversity

The variety of life in the world or a particular habitat or ecosystem.