Bell Warm Up 2-16-10 Make an inference about this picture. Give a possible fact about this picture

Fact vs. Inference

Fact An Observation a thing that has been done something shown to exist something known to have existed

Inference Educated guess as to what happened based on facts (observations) Conclusion deduction judgment.

Can you guess what this is? Hints A lot of you uses a type of this every day Name Brand First Touch

Make an inference based off of the facts shown. IPOD Touch Make an inference based off of the facts shown. Magnifying lens picture may have told you it could surf the web Part of the star may have reminded you of one you’ve seen Colors sometimes give it away

What are the facts about this book? Deals with Algebra Its hard It has numbers on the cover 1 & 2 1 & 3 2 & 3 None of the above :40 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

What are the inferences about this picture? He has something to do with baseball He is wearing a uniform He has gloves on He just hit a ball 1 & 2 1 & 4 3 & 4 :40 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Scientist use facts about our history and make inferences about life on earth. One inferences is that change occurs over time.

Change over time A gradual process in which something changes into a different and usually more complex or better form

Bell Warm- Up 2/18/2010 Darwin’s theory of evolution suggest that: Choose one Species change over time b) Extinct species are not related to living species c) Different species can interbreed d) Animals that look alike are the most closely related

Evidence for Change over time

EMBRYOLOGY Another way to compare the anatomy of different species is to compare their embryos. The embryos of different vertebrates show similar stages of embryonic development 13

Much of the evidence for evolution comes from studying fossils. • A fossil is a remnant or trace of an organism from the past, such as a skeleton or leaf imprint, embedded and preserved inEarth’s crust.

Geological Distribution The organisms show particular patterns of distribution on earth. The distribution of the species give an indication of how the earth was earlier. Geological Distribution leds to change in species over time.

Anatomy Homologous Structures Vestigial Structures Analogous Structures

HOMOLOGOUS STRUCTURES Homologous structures have a common origin, but do not necessarily perform the same function. The structures in the limbs below indicate that the organisms are related by a common ancestor. 17

Vestigial Structure A vestgial structure is an structure whose original function has been lost during evolution. From reference.com

Examples of Vestigial Organs Appendix Coccyx Wisdom teeth Goose bumps Plantaris muscle External ear muscles Image courtesy of BIODODAC website http://biodidac.bio.uottowa.ca

The Coccyx Former function was to support the tail and the nerves associated with the tail. Formed from 4 fused coccyx. Currently used as a point of muscle attachment for the gluteus maximus. Has a shock absorber function Image courtesy of BIODODAC website http://biodidac.bio.uottowa.ca

Goose bumps Goose bumps are a vestigial reflex. From www.beakman.com Goose bumps are a vestigial reflex. In furry mammals, goose bumps allowed the fur to stand on end, making the animal appear larger to enemies. Goosebumps still serve a function in warming humans, as many thousands of tiny muscles contract creating heat. From wikipedia.com

Wisdom Teeth Called wisdom teeth because they erupt at ages Image courtesy of BIODODAC website http://biodidac.bio.uottowa.ca Wisdom Teeth Called wisdom teeth because they erupt at ages 17-21, an age when a person is wiser than they were when earlier teeth erupted! Most people have 4 Wisdom teeth but the range is usually between 0 and 4. Often they are impacted (lodged in bone or soft tissue) and unable to erupt. Several theories exist on why wisdom teeth have such limited utility We eat a more refined diet with less use for extra molars Our teeth are less likely to be lost to decay, making “replacements” unnecessary. Man has evolved a smaller jaw. From https://www.drbunn.com/3rds.htm and Wikipedia.com

Analogous Structures Body parts similar in use, but different in structure E.g. Bird wing and insect wing

Remember Homologous structure Homo  same : same structure different function Analogous structure Ana different or apart Different structure same function

Evidence for change over time: Re-cap Evidence for change over time: Embryology Fossils Geological distribution Anatomy Homologous Structures Vestigial Structure Analogous Structures

Bell Warm Up 2-19-10 Define: Homologous Structures Analogous Structures Vestigial Structures Same Structure but different function. Different Structure but same function. Structures that we have but are no longer useful.

Change over time… This is what scientist call evolution

Charles Darwin Took a voyage to the Galapagos Islands. • During the trip, Darwin collected thousands of plant and animal species. • He was amazed at the diversity of life he encountered.

Darwin Cont. Darwin wrote down his observations and collected evidence about evolution. • That evidence led him to propose a theory about how evolution works called natural selection.

One of Darwin’s studies were of finches One difference he found was in the shape of their beaks. The shape of finch beaks appeared to differ with the type of food eaten.

Darwin concluded that finch beaks were adapted for the type of food they ate.

Darwin hypothesized that an ancestral species of finch from the mainland somehow ended up on the Galapagos Islands. The finches of that species scattered to different environments. • There, they had to adapt to different conditions. • Over many generations, they evolved adaptations that allowed them to get enough food to survive and reproduce. • Each group of finches became isolated from the other groups. • Eventually, each group became a different species.

Darwin's finches would apply to which evidence of evolution? Geological Distribution

Darwin reasoned that populations of organisms changed slowly as their environment slowly changed. • If the environment changes rapidly from an event like a flood, an earthquake, or a volcanic eruption, a species could become extinct (all members die off completely).

Based on his research and evidence, Darwin concluded that: 1. Organisms change over time. 2. All organisms are descended from common ancestors by a process of branching. 3. Evolution is gradual, taking place over a long time. 4. The mechanism of evolution is natural selection.

Bell warm Write one fact about this picture Write one inference about this picture How does this picture show natural selection

Natural Selection BrainPOP | Natural Selection

Definitions Fitness- the combination of physical traits and behavior that helps organisms survive and reproduce in their environment. Adaptation- the ability to adapt or to become better suited to a particular environment.

YouTube - Natural selection

Think about it Charles Darwin called the ability of an organism to survive and reproduce in its specific environment Diversity Fitness Adaption Evolution

Natural selection explains how a population changes in response to its environment. • Those changes are called adaptations

How’s it Work? So Natural Selection is the survival of the fittest! Selection Determines which individuals enter the adult breeding population This selection is done by the environment Those which are best fit for the environment will reproduce And they pass these well suited characteristics on to their young So Natural Selection is the survival of the fittest! What is meant by “fittest”?

Survival of The Fittest Individuals whose characteristics are well suited to their environment survive. Individuals whose characteristics are not well suited to their environment either die or leave fewer offspring.

• Most of the squirrels that survive to reproduce are brown. Imagine a population of brown squirrels that has a single gene that determines fur color. • The squirrels with brown fur can hide from predators better than squirrels with white fur. • Most of the squirrels that survive to reproduce are brown. • Since brown fur is a favorable adaptation, the allele for brown fur is selected over the allele for white fur.

What trait is being naturally selected for? Why do you think so?

What would happen to the frequency of the brown fur allele if the climate changed and the ground became covered in snow for most of each year?

Remember that a species is an isolated Natural Selection through Speciation and Adaption Scientists theorize that natural selection leads to the formation of new species. Remember that a species is an isolated population of similar organisms that interbreed and produce fertile offsprings.

One way for a new species to evolve happens in three steps: Isolation Adaptation Differentiation.

• The original population becomes divided into smaller populations. Isolation happens when a population becomes divided by an event such as floods, storms, volcanic eruptions, mountain formation, and earthquakes. • The original population becomes divided into smaller populations. • Each population is physically and reproductively isolated from the others.

Over time, each separated population may become adapted to their environment And if the environments are different, each population will have different adaptations.

Differentiation happens when the isolated populations become so different that they can no longer interbreed, even if they could unite again. Over many generations, the isolated populations become genetically different from each other.

As a result, one or more new species are formed.

Natural Selection through Behavior Natural Selection can select for organisms with greater behavioral abilities http://www.youtube.com/watch?v=woZIhsO2RZU&feature=related

Natural Selection through Extinction Nature Selects against a particular trait which leads to the extinction of the organism with that trait.

Artificial Selection nature provides variation then humans select variations that are useful to them. Example - a farmer breeds only his best livestock.

Draw a picture to explain natural selection