Evolution: Foundation of modern biology How is life on Earth so diverse, yet has so much in common?

Bell Ringer – 05/07 Write down three things you remember about evolution. How does evolution happen? Learning Target : We will review the key concepts of evolution. Closure task : I will complete Part 1 of my Critter Project.

Agenda Evolution review Critter Project part 1

What is evolution? Describes how species change over time Indicates common ancestry—all species on earth have evolved from the first life on earth (prokaryotes) Charles Darwin proposed that the mechanism of evolution is natural selection  Artificial selection: breeding dogs, plants, etc  Given enough time (4.6 billion years), couldn’t the diversity of life result from selection by the environment?

Myths & Misconceptions about Evolution TED-Ed: Myths & Misconceptions about evolution

Need to Know Individuals don’t evolve, populations do!  A frog couldn’t adapt to life in the desert.  However, if conditions in its habitat changed, this would gradually change the genetics of the population. Organisms don’t adapt!  An adaptation is a genetic change (can be physical or behavioral).  Adaptations are NOT acquired traits, they are inherited.

Evidence for Evolution 1. Molecular evidence : DNA & proteins a.The DNA code is read the same way by all species on earth, from bacteria to plants to humans. b.DNA comparison– the more similarities, the more closely related

All life on earth shares a common genetic code!

Which organism shares the most recent common ancestor with humans? OrganismAmino Acid Sequence Organism 1…Q A G Y S T D K… Organism 2…M A Q F S T D K… Organism 3…Q A Y P S T D K… Organism 4…Q A P F T T D K… Human…Q A P Y S T A K…

Evidence for Evolution 2. Embryologic evidence : Development a.Early embryos of many animals look similar.

Evidence for Evolution 3. Fossil evidence a.The fossil record provides evidence of how species have changed over time; radiometric dating lets us determine how old fossils are.

Evidence for Evolution 4. Comparative anatomy a.Homologous and vestigial structures provide evidence of common ancestry.

Comparative Anatomy Homologous structures : Similar between different species, but adapted for different uses.  Ex: forelimb (arm) of whales, humans, bats, and birds have the same bones, but have evolved for different purposes. Vestigial structures : Structures that do not have a purpose in a modern organism, but were useful to ancestors of that organism  Ex: hind limb bones in whales & snakes; human—wisdom teeth, muscles that raise hairs, tailbone

Theories of evolution Catastrophism Gradualism Punctuated equilibrium

4 points of natural selection 1. Variation exists within a population (genetic differences). 2. Organisms compete for scarce resources. (Selection pressure) 3. Some individuals are better suited to the environment due to their genetic variation (ex: a giraffe with a slightly longer neck). 4. Differential reproduction: those organisms that are more successful obtaining mates, food and other resources will be able to reproduce and pass on their genes more. Over time, the genetics of the population changes—this is evolution!

Natural Selection Concept Map 1. Natural selection 2. Evolution 3. Key words

4. Classify Characteristics of Natural Selection

Example or Non- Example

Example or Non-Example?

A body builder has a son.

Traits that have evolved through natural selection Courtship rituals Migration

What is Natural Selection? Natural selection in a nutshell (skip 4:10 – 4:20) Stated Clearly – Natural Selection Natural selection – crash course

Example of Evolution Antibiotic resistance

Critter Project Part 1 Clarification: #3 – Pick any adaptations.  Examples: fur color for camouflage, claws for grabbing onto prey, etc

Exit Slip: things you learned today 2 questions you still have/things you are unclear about 1 thing you will do to get ready for the EOC—be specific! How did you do? Rate yourself! We will review the key concepts of evolution. I completed Part 1 of my Critter Project.