Name. 2/03/10 #43. Section 6. 3 Notes. Many types of evidence Name 2/03/10 #43 Section 6.3 Notes Many types of evidence support evolution fossil genetic biological

What is a scientific theory? Scientific theory - widely accepted statement based on scientific evidence that helps explain and predict natural phenomena Can you list any scientific theories? Theory of evolution Atomic theory Theory of relativity Big bang theory The germ theory of illness

What do you need to prove a theory is accurate? Evidence that confirms the theory Can theories change? If so, how? Yes, theories can change if new evidence becomes available. What evidence supports the theory of evolution? The theory of evolution has been built on three sources of evidence: fossil, biological and genetic.

How does fossil evidence support evolution? Fossil evidence shows that two species with a common ancestor can develop differently ancestor – an early form of an organism from which later forms descend Example: The glyptodon resembles the modern armadillo found in South America today.

How does biological evidence support evolution? Scientists use biological evidence by studying the structure and development of living things. Scientists focus three things: -Vestigial organs -Homologous structures -Embryonic Development

Vestigial organs Vestigial organs are physical structures that are no longer useful to a living organism, but may have existed as fully developed structures in an ancestor.

Vestigial organs Human examples: -tail bone -appendix -wisdom teeth

Homologous Structures Homologous Structures – Many different species share similar body structures. However, these structures are used differently by each species. The similarity shows that the organisms share a common ancestor.

Homologous Structures Label the following structures found in each organism: 1) carpals 2) radius 3) humerus 4) phalanges 5) metacarpals 6) ulna 3 2 6 1 5 4

Embryonic Development There are many organisms that look very similar during embryonic development (earliest stages of life). As the organisms develop, they look less and less alike. These similarities again show that the organisms share a common ancestor.

How does genetic evidence support evolution? Similar organisms have very similar genes Less closely related organisms have genes that are much easier to tell apart. The similar patterns in DNA show the organisms share a common ancestor.