Change Over Time Are living things related to

Change Over Time Are living things related to other living things? Why do living things change? How do living things change? Aqua is the color

8. L. 4 Understand the evolution of organisms and landforms based on evidence, theories and processes that impact the Earth over time. • 8. L. 4. 1 Summarize the use of evidence drawn from geology, fossils, and comparative anatomy to form the basis for biological classification systems and theory of evolution. • 8. L. 4. 2 Explain the relationship between genetic variation and an organism’s ability to adapt to its environment.

In your own words, describe what YOU think theory of evolution means…

Charles Darwin

Darwin’s Theory of Evolution n Evolution, or change over time, is the process by which modern organisms have descended from ancient organisms. n A scientific theory is a well-supported testable explanation of phenomena that have occurred in the natural world.

How do you think Darwin came up with his theory? Darwin Video

Voyage of the Beagle

Voyage of Beagle Dates: February 12 th, 1831 n Captain: Charles Darwin n Ship: H. M. S. Beagle n Destination: Voyage around the world. n Findings: evidence to propose a revolutionary hypothesis about how life changes over time n

Patterns of Diversity n Darwin visited Argentina and Australia which had similar grassland ecosystems. u u those grasslands were inhabited by very different animals. neither Argentina nor Australia was home to the sorts of animals that lived in European grasslands.

Patterns of Diversity n Darwin posed challenging questions. u Why were there no rabbits in Australia, despite the presence of habitats that seemed perfect for them? u Why were there no kangaroos in England?

Living Organisms and Fossils n Darwin collected the preserved remains of ancient organisms, called fossils. n Some of those fossils resembled organisms that were still alive today.

Living Organisms and Fossils Others looked completely unlike any creature he had ever seen. n As Darwin studied fossils, new questions arose. u Why had so many of these species disappeared? u How were they related to living species?

Fossils provide evidence

The Galapagos Islands n The smallest, lowest islands were hot, dry, and nearly barren-Hood Island-sparse vegetation n The higher islands had greater rainfall and a different assortment of plants and animals-Isabela- Island had rich vegetation.

Animals found in the Galapagos n Land Tortoises n Darwin Finches n Blue-Footed Booby n Marine Iguanas

The Galapagos Island n Darwin observed the animals n Darwin was fascinated in particular by the land tortoises and marine iguanas in the Galápagos. n Giant tortoises varied in predictable ways from one island to another. n The shape of a tortoise's shell could be used to identify which island a particular tortoise inhabited.

If the only available food is located high on a bush, which turtle is better adapted to eat?

There are finches on the mainland on all the islands The finches are very similar except for their beaks The beaks differ from island to island The beaks are always a match to the food source.

Darwin reasoned Ø the finches began as a single species in Equator Ø As competition for space & food increases, some finches fly to one of the islands. Ø The food source on that island is slightly different, finches lucky enough to have the ‘right’ beak for the new food – eat, grow, develop, reproduce & pass on that “beak” trait. Ø Over time, more & more of the finches have the ‘new’ beak Ø A new species of finch begins. Ø Repeat to other islands

Different beaks -- different food source --- less competition

What did Darwin find out? How did Darwin interpret his observations? Observation Inference Very similar birds All finches Lots of variation Lots of competition Environment can only support a limited number of birds By chance, some birds inherit beaks that enable them to eat different foods Eat – survive -- reproduce – Pass on “good” trait Group 1 Group 2 Original beak New beak The birds share common ancestry Similar birds Different beaks Different food sources More birds can share same environment because they are not eating the same food Natural Selection -Species change, morph toward better balance with environment -One species splits into 2 species

The Journey Home n Darwin Observed that characteristics of many plants and animals vary greatly among the islands n Hypothesis: Separate species may have arose from an original ancestor

Lamarck

Lamarck’s Theory of Evolution n Tendency toward Perfection(Giraffe necks) n Use and Disuse (bird’s using forearms) n Inheritance of Acquired Traits https: //www. youtube. com/watch? v=4 HBdx. DBqf. Hc

https: //www. youtube. com/watch? v=VDh. Nutb. Xp. FE

The Science Theory of Evolution • Species* change over time and space – staying a good match to their environment *species = populations of interbreeding organisms • All organisms share common ancestors with other organisms. explains the similarities of organisms & the inheritance of traits • The primary mechanism of change over time is natural selection.

Speciation n The formation of new species as a result of geographic, physiological, anatomical, or behavioral factors that prevent previously interbreeding populations from breeding with each other.

Essential Question Why do some organisms survive and others do not?

Moth Story There is naturally variation in the color in moth offspring - light to dark gray. In the original forest, moths live near tree trunks that are light in color. In this environment the light gray color moths have advantage. (matching the tree color helps them not get eaten, so they can eat and survive. ) However, when a new factory is built nearby soot and smoke accumulates in the air causing the tree trunks to darken. In terms of Natural Selection - what will happen to the moth population? Let’s explain how that will happen Natural selection (12: 44): http: //www. youtube. com/watch? v=a. Tfty. Fbo. C_M&safe=active

Natural Selection

If you can eat. . What’s the rest of the story? you survive You reproduce Pass on your “good” traits Why is “good” in “ ”?

Mutation n A mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene.

Modification n Shows how as organisms reproduce, slight changes create variation, which could lead to new species over time.

Adaptation n When an organism becomes better fitted to survive and multiply in its environment.

Extinct Species n A species that no longer exists anywhere on earth

Natural Selection & Artificial Selection n Natural variation--differences among individuals of a species n Artificial selection- nature provides the variation among different organisms, and humans select those variations they find useful.

Struggle For Existence & Survival of The Fittest

Evolution by Natural Selection n The Struggle for Existence-members of each species have to compete for food, shelter, other life necessities n Survival of the Fittest-Some individuals better suited for the environment

Natural Selection n Over time, natural selection results in changes in inherited characteristics of a population. These changes increase a species fitness in its environment

2 ways the present day chicken is better adapted to today’s environment than its ancestor would have been 1. smaller size – needs less food for survival, 2. has feathers rather than fur – lighter and water resistant – can fly?

Descent n n Descent with Modification-Each living organism has descended, with changes from other species over time Common Descent- were derived from common ancestors

Evidence for Evolution n The Fossil Record n Geographic Distribution of Living Things n Homologous Body Structures n Similarities in Early Development

Evidence for Evolution n n The Fossil Record. Layers show change Geographic Distribution of Living Things Homologous Body Structures Similarities in Early Development

Evidence of Evolution n n The Fossil Record Geographic Distribution of Living Things-similar environments have similar types of organisms Homologous Body Structures Similarities in Early Development

Homologous Structures n Homologous Structures-structures that have different mature forms in different organisms, but develop from the same embryonic tissue

Comparative Anatomy In what specific ways are these ‘forearms’ alike?

Comparative Anatomy 1 bone hinge joint 2 bones hinge joint many bones

Comparative Anatomy • Common prototypesbackbone, legs, eyes • Internal organs – heart, digestive, nervous · Same structure modified for different purposes

Well adapted animals have advantage in their environment Let’s activate our thinking with this brainstorm: Limbs help an animal move - but there are lots of variations. Record 3 different types of limbs & how they help animals move

Evidence for Evolution n Vestigial organs-organs that serve no useful function in an organism n i. e. ) appendix

• LIFE (2: 21) Mudskipper: http: //dsc. discovery. com/tv-shows/life

In what specific ways are these ‘body forms’ alike?

Backbone – made of vertebrae Rib cage – protects internal organs 2 pairs of limbs – forward & aft Skull – houses brain Teeth Jaw Eyes Hearty

Similarities in Early Development

What’s an embryo? Embryology = the study of embryos How does embryology support the Theory of Evolution? ·Similar developmental pattern ·Supports common ancestry

Evidence of Evolution Embryology How does embryology support the Theory of Evolution? ·Similar developmental pattern ·Supports common ancestry Embryos and DNA (3: 43) : http: //www. dnatube. com/video/420 7/What-Can-Embryos-Tell-Us. About-Evolution

Evidence of Evolution Embryology How does embryology support the Theory of Evolution? ·Similar developmental pattern ·Supports common ancestry

Evidence of Evolution DNA How does DNA support the Theory of Evolution? · DNA has double helix structure · All animal DNA very similar (except human) · Plant DNA similar but with less chromosome pairs · All DNA has similar nucleic acids

4 Key Points that support the Theory of Evolution #1 • in any population, lots of offspring are born • many die • There is a struggle to survive

4 Key Points that support the Theory of Evolution #2 • There are variations within a population • Some variations make it easier to survive

4 Key Points that support the Theory of Evolution #3 • Well adapted adults survive (eat & don’t get eaten) • grow & develop • reproduce • pass on traits • resulting in well adapted offspring

4 Key Points that support the Theory of Evolution #4 • As the environment changes, different variation in traits help an organism survive. • Individuals with these variations survive Adaptation & Evolution is always about the ones who survive!!

Taxonomy Copy Chart

What is classification? n Classification is the grouping of things according to characteristics n The science of classifying organisms is known as taxonomy http: //app. discoveryeducation. com/player/view/asset. Guid/3 A 93 EAFB-EE 6 A-45 D 7 -8836 -D 50 BCCCFDA 45

Summary of Darwin’s Theory n Individuals in nature differ from one another n Organisms in nature produce more offspring than can survive, and many of those who do not survive do not reproduce.

Summary of Darwin’s Theory n Because more organisms are produce than can survive, each species must struggle for resources n Each organism is unique, each has advantages and disadvantages in the struggle for existence

Summary (cont. ) n Individuals best suited for the environment survive and reproduce most successful n Species change over time

Summary (cont. ) n Species alive today descended with modification from species that lived in the past n All organisms on earth are united into a single family tree of life by common descent Meerkat Adaptations (45 sec): http: //video. nationalgeographic. com/video/education-videos/education-general/edu-meerkatadaptations/ Zebra Stripes: http: //animal. discovery. com/tv-shows/other/videos/fooled-by-nature-zebras-stripes. htm

King Tut: http: //dsc. discovery. com/tvshows/othershows/videos/king-tutunwrapped-collecting-royaldna. htm

Meerkat Adaptations (45 sec): http: //video. nationalgeographic. com/video/education-videos/education-general/edu-meerkatadaptations/ Zebra Stripes: http: //animal. discovery. com/tv-shows/other/videos/fooled-by-nature-zebras-stripes. htm

Review Vocabulary Jeff Corwin Galapagos: https: //www. youtube. com/watch? v=j. Rz. I 0 y. THBWU And Man Created Dog: https: //www. youtube. com/watch? v=GFzb. BVMR 8 z. A