1 / 8

HOW DID LIFE GET HERE – BY DESIGN OR BY CHANCE?

HOW DID LIFE GET HERE – BY DESIGN OR BY CHANCE?. The Flagellum Motor. IRREDUCIBLE COMPLEXITY AND THE BACTERIAL FLAGELLUM. © Keiichi Namba, 2002. Learning Outcomes. You should learn: How explanations of many phenomena can be developed using scientific theories, models and ideas.

aretha
Download Presentation

HOW DID LIFE GET HERE – BY DESIGN OR BY CHANCE?

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. HOW DID LIFE GET HERE – BY DESIGN OR BY CHANCE? The Flagellum Motor IRREDUCIBLE COMPLEXITY AND THE BACTERIAL FLAGELLUM © Keiichi Namba, 2002

  2. Learning Outcomes You should learn: • How explanations of many phenomena can be developed using scientific theories, models and ideas. • To … develop an argument and draw a conclusion, using scientific and technical language. • How uncertainties in scientific knowledge and scientific ideas change over time and about the role of the scientific community in validating these changes.

  3. Is Darwinism True? • In the Origin of Species, Darwin wrote: “If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.”

  4. How Bacteria Swim • Certain bacteria have tiny propellers called flagella which they use to swim. • Flagella look like hairs, but up close they are amazingly complex.

  5. The Biochemical Challenge • In 1996, Mike Behe, a Professor of Biochemistry, saw that the flagellum system presented a big problem for Darwin’s theory of evolution. He developed the term ‘irreducible complexity’ to describe this problem. • Since 1996, many other professional scientists have agreed with him – including molecular biologist Scott Minnich.

  6. Irreducible Complexity • Behe defined an IC System as: ‘…a single system that is necessarily composed of several well-matched, interacting parts that contribute to the basic function, and where removal of any one of the parts causes the system to effectively cease functioning’. • To provide a simple illustration, Behe pointed to a mousetrap as the product of an intelligent design:

  7. Have Parts Been Reused? Parts of the flagellum, used for other functions, may have been re-used to evolve the tiny propeller without intelligent direction. However, there are major problems with this idea: 1. Many parts of this tiny propeller are unique to it alone. 2. Assembly instructions for the flagellum also direct the sequence in which the parts will be built, and exactly how they will be assembled. 3. These instructions are read and processed by a network which is itself irreducibly complex. 4. The need to imagine many new part functions for natural selection to select, stretches the scientific credibility of this idea.

  8. Assembly of the Flagellum Where does the evidence lead? Design or Chance? © Keiichi Namba, 2002

More Related