Origins and Evolution

A set of vocabulary flashcards covering key concepts from the lecture on the origins and evolution of life, focusing on evolutionary theory, early life evidence, and the mechanisms of microbial evolution.

Origins of Life

The beginning of biological existence, which required essential elements, an energy source, and a temperature range for liquid water.

Prebiotic Soup Theory

The hypothesis that life originated from simple organic molecules formed abiotically through processes such as lightning.

Stromatolites

Layered structures created by microbial communities, considered the earliest evidence of life on Earth.

Biosignature

Biological indicators that provide evidence of past or present life, such as isotope ratios or chemical markers.

Hadean Eon

The earliest period of Earth's history, from 4.6 to 4.0 billion years ago, characterized by extreme conditions and bombardment by meteors.

Archaean Eon

The period from 4.0 to 2.5 billion years ago during which the first signs of life, such as microbial life forms, appeared.

Horizontal Gene Transfer

The process by which organisms, especially prokaryotes, transfer genetic material between cells, distinct from vertical inheritance.

Natural Selection

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

Phylogeny

The evolutionary history and relationship among groups of organisms, often represented as a phylogenetic tree.

Endosymbiosis

A symbiotic relationship in which one organism lives inside the other, crucial to the evolution of eukaryotic cells, involving mitochondria and chloroplasts.

RNA World Hypothesis

A theory proposing that early life was based on RNA, which played roles in both genetic information storage and catalysis.

Mitochondria

Organelles that evolved from an ancestral alpha-proteobacterium, playing a key role in energy production in eukaryotic cells.

Chloroplasts

Organelles that originated from cyanobacteria and are responsible for photosynthesis in plant cells.

Microbial Species

In microbiology, a group of prokaryotic organisms that reproduce asexually, often defined by genetic similarities rather than reproductive isolation.

Pangenome

The complete set of genes within a species that includes both core genes shared by all members and accessory genes present in some but not others.

Experimental Evolution

A method of studying evolution in a controlled laboratory environment to observe evolutionary changes and mechanisms.