Similar traits often indicates common ancestry Phylogeny: evolutionary histories of a species Determined by examining: –Fossils –Living specimens –Molecular data –Development

Fossil Evidence Homologous structures: body parts that have a similar structure, but different function Relationships identified among different species Fossils link past life to modern life

Anatomy shows nonrelationships also

Comparing DNA, amino acids, chromosomes, proteins –Similarities and differences can be found DNA mutates at known rates –Splits in evolution can be estimated

Chromosome order: Human, orangutan, gorilla, pygmy chimp

Zygote divides by mitosis (1  2  4  8) Blastula (ball of cells) forms Blastopore (small indentation) begins to form digestive system Blastopore develops into the anus of some animals and mouth of others Conclusion: Similar development indicates relationship

Which two organisms are more closely related to one another? In both humans and starfish, the blastopore becomes our anus…. In insects, the blastopore becomes their mouth.

Defined: the evolutionary history of a species Cladograms used to show order in which species evolved from their ancestor Evidence from morphology, biochemistry, fossils, embryology are used to build cladograms Phylogeny

Earth cities E. hemisphere France Italy Dallas Paris Las Vegas Rome Quebec Rio de Janeiro W. hemisphere S. America N. America Canada USA Nevada Texas Choices: Paris Rio de Janeiro Dallas Quebec Las Vegas Rome Very broad Less broad Very specific Paris Rome Rio de Janeiro Dallas Quebec Las Vegas Dallas Quebec Las Vegas Dallas Las Vegas

Earth cities E. hemisphere France Italy Dallas Quebec W. hemisphere S. America N. America Canada USA Nevada Texas What does Dallas and Quebec have in common? Paris Rome Rio de Janeiro Dallas Quebec Las Vegas Dallas Quebec Las Vegas Dallas Las Vegas Earth cities, W. Hemisphere, N. America

Defined: the evolutionary history of a species Cladograms used to show order in which species evolved from their ancestor Evidence from morphology, biochemistry, fossils, embryology are used to build cladograms Phylogeny List the characteristics of a salamander. Jaws Lungs

Defined: the evolutionary history of a species Cladograms used to show order in which species evolved from their ancestor Evidence from morphology, biochemistry, fossils, embryology are used to build cladograms Phylogeny What does a mouse and lizard have in common?

1) What does an amphibian & crocodile have in common? Vertebrae, Bony skeleton, Four limbs 2) List the traits of a ray-finned fish. Vertebrae, bony skeleton, does not have 4 limbs 1 minute: Discuss with your neighbor

These are the same cladograms in two different formats. What does an amphibian & rabbit have in common?

How many of these 8 species have calcitic sclerites?

How many of these 8 species have a common coenchyme? 12345

How many of these 8 species have eight fully developed mesenteries? 12

Review 1)What is morphology and how can it be used to help classify organisms? 2)What are homologous structures and how is it used to help classification? 3)How can molecular evidence like DNA and chromosomes be used to classify life? 4)What does it mean if two different organisms develop along similar pattern? Different patterns? 5)List the traits of birds. 6)What do birds and prosimians have in common? 7)Which trait separates insects from the rest?