Origins and Evolution - Chapter 17

Flashcards for defining key concepts related to the origins and evolution of life, based on lecture notes.

Prebiotic Soup Theory

Proposes that fundamental biomolecules of life arose spontaneously through condensation of reduced inorganic molecules.

Stromatolites

Earliest forms of life for which clear fossil evidence exists, consisting of bacterial communities.

Banded Iron Formations (BIFs)

Evidence of the evolution of the first oxygenic phototrophs, indicating periods of alternating oxygen-rich and anoxic conditions in early Earth's history.

Horizontal Gene Transfer

Acquisition of a piece of DNA from another cell, as opposed to vertical gene transfer, which transmits an entire genome from parent to offspring.

Natural Selection

Mechanism of evolution where variants that survive and reproduce pass on their traits to the next generation.

Endosymbiosis

Intimate association of two unrelated species, where one partner grows within the body of another, leading to coevolution.

Phylogenetic Tree

A diagram that represents the evolutionary relationships among various biological species based on similarities and differences in their physical or genetic characteristics.

RNA World

Model in which RNA is suggested to have performed all informational and catalytic roles in early life, before DNA and proteins.

Isotope Ratios

Quantitative measures used as biosignatures, altered by biological activity, that can provide evidence for early life.

Microbial Species

Prokaryotic grouping, defined through genetic relatedness rather than through reproductive methods like in eukaryotes.