{ Evidence for Evolution Part 1 Fossil records, zoogeographical maps, DNA sequences, homologous, analogous. Warm-up Questions: Which scientist coined the theory of evolution while studying finches? ________________ is the term used for when natural selection leads to the creation of a new species. Charles Darwin Speciation

 There are several places we can see evidence of evolution/evolutionary relationships:  -fossils,  -comparative anatomy,  - biochemistry/DNA,  -embryology,  - and biogeography. Evidence of Change Over Time

 Fossils are evidence of organisms that lived long ago that are preserved in Earth’s rocks. TYPES OF FOSSILS Fossils TypesFormation Trace fossils Casts Molds Petrified fossils Amber-Preserved or frozen fossils A trace fossil is any indirect evidence left by an animal and may include a footprint, a trail, or a burrow. When minerals in rocks fill a space left by a decayed organism, they make a replica, or cast, of the organism. A mold forms when an organism is buried in sediment and then decays, leaving an empty space. Petrified-minerals sometimes penetrate and replace the hard parts of an organism At times, an entire organism was quickly trapped in ice or tree sap that hardened into amber.

 Scientists who study ancient life by using fossils to understand events that happened long ago. Paleontologist: They use fossils to determine the kinds of organisms that lived during the past and sometimes to learn about their behavior.

 For fossils to form, organisms usually have to be buried in mud, sand, or clay soon after they die.  Fossils are not usually found in other types of rock due to the ways those rocks form.  Example: the conditions under which metamorphic rocks form often destroy any fossils that were in the original sedimentary rock. Fossil Formation:

 Few organisms become fossilized because, without burial, bacteria and fungi immediately decompose their dead bodies.  Occasionally, however, organisms do become fossils in a process that usually takes many years. Fossil Formation Contd. How fossils form

 Scientist use several methods for determining the age of a fossil.  This method indicates that the fossils found closer to the surface, in an undisturbed ground, are younger, and the fossils found in deeper strata are older.  This method only gives a relative age between the fossils and not a specific age of the fossils. Relative Dating:

Relative Dating Contd. Using this principle, scientists can determine relative age and the order of appearance of the species that are preserved as fossils in the layers.

 There are two types, homologous and analogous. Anatomical Evidence:

 Structural features with a common evolutionary origin  Science sees structural similarities as evidence that organisms evolved from a common ancestor.  Homologous parts are similar in structure, but may be very different in specific function. Homologous Structures:

 The body parts of organisms that do not have a common evolutionary origin but are similar in function.  Analogous parts are very different in structure, but perform similar functions. Analogous Structures:

 A body structure in a present-day organism that no longer serves its original purpose, but was probably useful to an ancestor. Vestigial Structure: Video

 Scientists believe that the fact that ALL LIVING THINGS have A,T,C, and G in their DNA and all use the same coding for proteins means we are all related in some way. Biochemical Relationships:

 The study of how similar embryos are for different organisms (may be evidence of relation) Embryology:

 Scientists believe the shared features in the young embryos of different species suggest evolution from a distant, common ancestor. Embryology Contd. Fish ReptileBirdMammal Pharyngeal pouches Pharyngeal pouches Tail

ChickenTurtle Rat