Origin and Evolution of Life on Earth

Vocabulary flashcards about the origin and evolution of life on Earth, covering topics from the Big Bang to the development of multicellular organisms and dating techniques.

The Big Bang Theory

Explains the origin of the universe, positing that 15 billion years ago, the universe was a dense mass that exploded, moving energy and matter.

Red Shift

The phenomenon where light from objects moving away from Earth has a longer wavelength, appearing redder.

Expanding Universe

The idea that the distance between galaxies is increasing over time, supported by the observation of red shifts in light from distant galaxies.

Relative Age Dating

Determining the age of a fossil or event based on its position in rock strata, with older layers typically found at the bottom and younger layers at the top.

Index Fossil

The remains of plants and animals that existed for a limited geologic period, used to narrow down the age of the rock containing them and correlate rock layers across different locations.

Absolute Dating (Radiometric Dating)

Using the radioactive decay of an element to determine the exact age of a rock or fossil.

Half-life

The time it takes for half of the radioactive nuclei in a sample to undergo radioactive decay.

Radioactive Carbon-14 Dating

A method used to date relatively young fossils or other organic material by measuring the decay of radioactive carbon-14; applicable to materials younger than about 50,000 years old.

Potassium-Argon Dating

A method using the decay of Potassium-40 to Argon, useful for dating volcanic rocks, with a half-life of 1.3 billion years.

Uranium-Lead Dating

An important method for determining the ages of rocks, calibrating the history of life on Earth, and measuring when the solar system formed.

Chemical Evolution

The process by which small inorganic molecules were converted to larger organic molecules, eventually leading to the formation of life.

Oparin-Haldane heterotroph hypothesis

The hypothesis that life arose from the accumulation of small inorganic molecules that formed larger organic molecules in the oceans, powered by energy sources like lightning.

RNA hypothesis

The theory that RNA was the first organic polymer to develop, serving as both an information molecule and a catalyst.

Ribozymes

RNA molecules that act as enzymes.

Biological Evolution

The process of self-reproduction, mutation, and natural selection that leads to the evolution of life forms.

Lipid World

The hypothesis that cell membranes evolved from lipids, providing a stable environment for the development of life.

Microfossils

Tiny, single-celled prokaryotes that resemble bacteria, found in 3.5 billion-year-old rocks.

Prokaryotes

The only organisms on earth for about 2 billion years. These single-celled organisms lack a nucleus and other complex organelles.

Stromatolites

Fossil formations made by cyanobacteria (blue-green algae), dating back about 2.5 billion years.

Endosymbiotic hypothesis

The theory that mitochondria and plastids were once free-living prokaryotes that were absorbed by larger cells and lived symbiotically.