Mind Stretcher 3/9/16 1. Which of the following symbiotic relationships is considered parasitic? A. ticks taking nutrients from a dog B. bees transporting pollen from flowers C. pilot fish swimming under sharks D. birds eating the insects from the back of a hippopotamus 2. Ants and acacia trees have a mutualistic relationship because… A. they benefit each other. B. they are part of the same ecosystem. C. they are both adapted to a humid climate. D. the ants eat part of the acacia tree.

The Evolution of Living Things

Georgia Performance Standards (GPS)  S7L5 Students will examine the evolution of living organisms through inherited characteristics that promote survival of organisms and the survival of successive generations of their offspring. S7L5.a Explain that physical characteristics of organisms have changed over successive generations (e.g. Darwin’s finches and peppered moths of Manchester). S7L5.c Trace evidence that the fossil record found in sedimentary rock provides evidence for the long history of changing life forms.

Let’s compare…. Rough Green Snake Corn Snake

Key Vocabulary A species is a group of organisms that can mate with one another to produce fertile offspring. (fertile means can have offspring too!) Speciation- the formation of new and distinct species in the course of evolution.

Speciation In their separate niches, the groups of shrimp go their own evolutionary ways, accumulating different gene mutations, being subjected to different environmental factors, experiencing different historical events, finally becoming incapable of interbreeding should they ever come together again.

Key Vocabulary A characteristic that helps an organism survive and reproduce in its environment is called an adaptation. Examples of Adaptations: Hibernation, Camouflage, migration, hair, resource conservation What type of adaptation is shown in the picture? a. homologous structure b. artificial selection c. camouflage d. mimicry

Camel Adaptations Rap VideoID=53373&CategoryID= VideoID=53373&CategoryID=2855 Pay attention to the various ways camels are ADAPTED to their environment…

Camouflage The ability to blend into the surrounding environment is helpful when avoiding a predator Examples: Scorpionfish and leaf frogs- can change their appearance to match their surroundings. Walking stick- looks very much like a twig Zebras fool would-be predators;  to a lion, they may look more like a mass of black-and-white stripes than a delicious prey species! Copy 2 examples!

Hibernation EX: chipmunks, hedgehogs, bats and bears. It’s usually quite difficult to stir these animals during hibernation!

Migration Movement of a population of animals as they migrate from one place to another Reasons -finding food and a good place to mate. Example- the arctic tern makes an annual migration from its breeding grounds in the Arctic to its wintering grounds in Antarctica, covering a distance of 25,000 miles!

Hair Hair offers important protection from the elements Musk Ox- Its thick, shaggy hair hangs down to the ground and gives the ox the protection it needs to endure frigid temperatures in the Alaskan tundra. (Winter temperatures= average of -30°F) Sheds some hair in time for summer, to itself cool down as temperatures reach 40-50°F Copy the red!

Resource Conservation Scarce/limited resources? Ability to conserve fat and water in the body can mean the difference between life and death EX: Bactrian camel, a two-humped ungulate that lives in the rocky and arid regions of Central and Eastern Asia, where temperatures range from -20°F in winter to 100°F in summer. humps are filled with fat, which can be converted into energy and water can forgo sweating until their body temperatures reach nearly 105°F.

Do species change over time? Yes, The process in which populations gradually change over time is called evolution.

Ways Evolution Can Occur: Punctuated Equilibrium: Species evolve very rapidly and then stay the same for long periods of time Gradualism: Slow, constant change

Mind Stretcher: The following statements describe the process of speciation. Fill in the appropriate term in each sentence and put them in the correct order in which they occur: Terms: division, separation, adaptation COPY- The process of speciation begins with ________, when part of a population splits apart. Because they respond to different environmental conditions over time, organisms traits evolve through _________. Over time, the two groups become so different they are no longer able to interbreed. This is called ____________. adaptations separation division

Quick Demonstration… As the “food source” comes around to each table, QUICKLY pick out the 1 st M&M you see. The other food in the bucket is poisonous (candy corn) and you may NOT pick it! Set the M&M aside and wait to tally up the class results. Do NOT eat them…some have been used previously!

Which M & M colors were picked the most? Why? Relate the outcomes of the M&M activity to camouflage in nature. Give an example of an animal that uses camouflage to avoid predators. Explain. Think About It…

Evidence of change over time… The remains or imprints of once-living organisms found in layers of rock called fossils. Paleontologists work among some of the hundreds of fossilized skeletons at Nebraska's Ashfall Fossil Beds.

Sedimentary Rock Formation Formed from deposited sediments, as the sediments build up, pressure increases, pressure squeezes the bottom layers and they form rocks. (lithification) Laid down in layers or beds, younger beds are above the older beds Older Younger

How do we get a fossil? Fossils are RARE!

Using Fossils to Estimate Age By identifying which layer of sediment the fossil is found in, we can estimate the age of the animal. REVIEW: The diagram below shows a geologic cross section. Which rock layer most likely contains fossils of the most recently evolved organisms? A 1 B 2 C 3 D 4 MOST RECENT OLDEST *Identify layer of fossil = estimate age!

Fossil Record Scientists have made a “timeline of life” known as the fossil record. It organizes fossils by their estimated ages and physical similarities. Scientists examine fossil record to determine relationships between extinct and living organisms.

Additional Evidence: DNA DNA: Scientists can compare DNA and find similarities among traits

Additional Evidence: Embryology Embryology: During the very early stages of life (in the womb), many organisms go through similar stages of development.

Homologous Structures: Structures derived from a common ancestor. Homologous StructuresHomologous Structures (link to activity)

Evidence for Evolution Includes:  FOSSIL RECORD  DNA & TRAITS  HOMOLOGOUS STRUCTURES  EMBRYOLOGY

Tree of Life Video clip (4 min) VideoID=33080&CategoryID= VideoID=33080&CategoryID=4792

Ways to Show Evolutionary Relationships:  Branching Tree Diagrams  “Tree of Life”- all species on Earth

 BRANCHING TREE DIAGRAM- diagram/model showing evolutionary relationships through shared characteristics

Which species’ has a jaw and lungs, but does not have claws or nails?

Tree of Life - includes all known organisms on Earth. (Incomplete… new species always being discovered)

Natural Selection and Adaptations

Natural Selection What is Natural Selection? Natural selection is the process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species. “Survival of the fittest!” Who's Going to Survive?

Charles Darwin & Theory of Natural Selection… British Naturalist aboard HMS Beagle Collected animal & plant samples Noticed variations among species…tortoise, finches, etc. Devised theory of natural selection

Warbler finch Woodpecker finch Small insectivorous tree finch Large insectivorous tree finch Vegetarian tree finch Cactus finch Sharp-beaked finch Small ground finch Medium ground finch Large ground finch Insect eaters Bud eater Seed eaters Cactus eater Warbler finch Tree finches Ground finches variation natural selection for best survival & reproduction From 1 species to 14 species…

Finch Beaks different beaks are inherited variations serve as adaptations that help birds compete for food these birds (who got the food) survive & reproduce pass on the genes for those more “fit” beaks over time nature “selected” for different species with different beaks

Relationship between species (beaks) & food

Natural Selection

There are several factors that Darwin identified that affect the process of natural selection: Overproduction of offspring Competition Variations SKIP two lines between each of these factors!

Overproduction Natural Selection Competition Variation

Overproduction - Most species produce far more offspring than can possibly survive

Competition -Struggle between organisms for the limited resources in a habitat

Variation - Any difference between individuals of the same species

Natural Selection: Examples Are these two butterflies the same species? These are the Monarch and Viceroy butterflies. The Monarch on the left is poisonous and the Viceroy is not. Question: Why would it be beneficial for the Viceroy to look like the Monarch?

Natural Selection: Examples Checkpoint: A species of hare (rabbit) that is found in a cold tundra environment. How are oversized feet an advantage to the Arctic Hare?

Natural Selection: Examples How many moths do you see?

DIRECTIONS: 1. Go to my.hrw.com and login to the textbook username: kilkenny11 password: x5s5dmy.hrw.com 2. Select "Go to Interactive Online Edition" Go to Chapter 7 and click on E-Activities (orange tab at the top) 3. Complete the Virtual Investigation