Chapter 10 Where did we come from? (from an evolutionist perspective)

Biological Evolution  Change in the characteristics of a biological population that occurs over the course of generations  Inherited genes,  Not factors dealing with temporary changes in the environment  Not behavioral  Ex. Antibiotic Resistance

Natural Selection  Microevolution (not debatable): changes that occur within a population  Macroevolution (debatable): changes that result in the origin of new species

Theory of Common Descent  The Theory of Common Descent states that all organisms originated from a common ancestor

Darwin & the Theory of Evolution   The observations that Charles Darwin found provided evolutionists with evidence of Biogeography

Evidence of Evolution  Homologies  Embryonic Development  Biogeography  The Fossil Record

Homologies: studying similarities  Anatomical Homology: comparison of similar anatomy in different species  Ex. Mammal forelimbs  Vestigial Traits - Traits without a function but had a function in a species evolutionary history

Molecular Homology  Molecular Homology: comparison of similar genes in different species

Embryonic Development  Developmental Homology: similarities in the process of development from fertilized egg to adult organism  Early embryos of different species look similar  Ex. Those with spinal cords share traits as embryos  Pharyngeal slits & tails

Biogeography  Distribution of the species of Earth  Darwin observed species that were unique to each island but had minor differences

The Fossil Record  Fossils: remains of living organisms left in soil or rock  Collections of fossils form a record of ancient life

Evidence Validity  Is this sufficient evidence to support common ancestry and the macroevolution?  Is there bias in science textbooks?  Is there scientific evidence against evolution?  Are there possible explanations for the appearance of these evidences?