1 / 9

KEY CONCEPT The origin of life on Earth remains a puzzle.

KEY CONCEPT The origin of life on Earth remains a puzzle. Earth was very different billions of years ago. There have been many hypotheses of Earth’s origins. The most widely accepted hypothesis of Earth’s origins is the nebula hypothesis. Sometimes also called the Big Bang Theory

Download Presentation

KEY CONCEPT The origin of life on Earth remains a puzzle.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. KEY CONCEPT The origin of life on Earth remains a puzzle.

  2. Earth was very different billions of years ago. • There have been many hypotheses of Earth’s origins. • The most widely accepted hypothesis of Earth’s origins is the nebula hypothesis. • Sometimes also called the Big Bang Theory • Age of Earth: 4.5-4.6 billion years old https://vimeo.com/11188228

  3. https://vimeo.com/11188228

  4. electrodes “atmosphere” water “ocean” heat source amino acids Several sets of hypotheses propose how life began on Earth. • There are two organic molecule hypotheses. • Miller-Urey experiment

  5. electrodes “atmosphere” water “ocean” heat source amino acids The Miller-Urey Experiment was based on Oparin’s Hypothesis: • Early Earth was warm, with lightning • Gases present: Water vapor, Hydrogen, Ammonia (NH3), Methane (CH4) • These combined to make first organic molecules. • The Miller-Urey Experiment made amino acids.

  6. Meteorite Hypothesis • Amino acids may have arrived on Earth through meteorite or asteroid impacts. • Evidence: Scientists have found amino acids on meterorites.

  7. Iron-sulfide bubbles hypothesis • Biological molecules first combined in compartments of chimmney-like structures on ocean floor • Compartments were first cell membranes. • There are different hypotheses of early cell structure.

  8. Lipid membrane hypothesis • Lipid spheres (liposomes) could form around a variety of organic molecules, acting as early cell membranes. • There are different hypotheses of early cell structure.

  9. A hypothesis proposes that RNA was the first genetic material. • Ribozymes are RNA molecules that catalyze their own replication. • DNA needs enzymes to replicate itself.

More Related