Chapter 22 - ClassNotes

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Class Notes Chapter 22: Descent with Modification: A Darwinian View of Life 8.31.09 CHAPTER 22: DESCENT WITH MODIFICATION: A DARWINIAN VIEW OF LIFE Overview: Endless Forms Most Beautiful A new era of biology began in 1859 when Charles Darwin published  The Origin of Species  The Origin of Species  focused biologists’ attention on the great diversity of organisms Darwin noted that current species are descendants of ancestral species Evolution  can be defined by Darwin’s phrase  descent with modification Evolution can be viewed as both a pattern and a process Concept 22.1: The Darwinian revolution challenged traditional views of a young Earth  inhabited by unchanging species The study of  fossils  helped to lay the groundwork for Darwin’s ideas Fossils are remains or traces of organisms from the past, usually found in sedimentary rock, which  appears in layers or  strata Paleontology , the study of fossils, was largely developed by French scientist Georges Cuvier Lamarck’s Hypothesis of Evolution  Lamarck hypothesized that species evolve through use and disuse of body parts and the inheritance of  acquired characteristics The mechanisms he proposed are unsupported by evidence Darwin’s Focus on Adaptation  In reassessing his observations, Darwin perceived  adaptation  to the environment and the origin of new  species as closely related processes The Origin of Species  Darwin developed two main ideas: Descent with modification explains life’s unity and diversity Natural selection is a cause of adaptive evolution In the Darwinian view, the history of life is like a tree with branches  representing life’s diversity Artificial Selection, Natural Selection, and Adaptation  Darwin noted that humans have modified other species by selecting and  breeding individuals with desired traits, a process called  artificial selection Darwin then described four observations of nature and from these drew two  inferences Darwin’s Observations Observation #1: Members of a population often vary greatly in their traits Observation #2: Traits are inherited from parents to offspring Observation #3: All species are capable of producing more offspring than the environment can support
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/12/2009 for the course BIO 1510 taught by Professor Unknown during the Fall '07 term at Georgia Institute of Technology.

Page1 / 5

Chapter 22 - ClassNotes

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online