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The Organization of Life

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1 The Organization of Life
Everything is Connected Activity: Draw a “connections web on the board. Start with a common animal, such as a blue jay, raccoon, or wasp. Write its name on the board and circle it. Then have students name interactions that this animal has with other plants and animals in its environment. For instance, blue jay eats insects, so you draw a line connecting the bird to the insect. Extend the connections and include abiotic factors (insect feeds on plant which uses sunlight). Continue until the web becomes complex. Introduce idea of an ecosystem, emphasizing that your web represents only a fraction of the interactions in a natural ecosystem at any given time.

2 Ecosystem All of the organisms living in an area together with their physical environment. Complex Systems Not easy to replace In San Diego, CA a marsh habitat, home to two endangered birds, was destroyed to build a freeway. To get the permit to build, the city had to promise to replace the ecosystem. Easier said than done. For example, when the endangered birds were released into their re-created ecosystem, they would not nest because the marsh grass wasn’t tall enough. The graass was shorter because a tiny beetle that fed on marsh-grass-eating insects was not present in the ecosystem. Without the beetle to control the insect population, the marsh grass could not grow to its full height.

3 Components of an Ecosystem
Abiotic—nonliving parts of the ecosystem. including air, water, rocks, sand, light, weather, and temperature Biotic—living and once living parts of an ecosystem. the light from the sun is a major constituent of a freshwater ecosystem, providing light for the primary producers, plants. There are many factors which can affect the intensity and length of time that the ecosystem is exposed to sunlight; Aspect - The angle of incidence at which light strikes the surface of the water. During the day when the sun is high in the sky, more light can be absorbed into the water due to the directness of the light. At sunset, light strikes the water surface more acutely, and less water is absorbed. The aspect of the sun during times of the day will vary depending on the time of the year. Cloud Cover - The cloud cover of an area will inevitably affect intensity and length of time that light strikes the water of a freshwater ecosystem. Species of plants rely on a critical period of time where they receive light for photosynthesis. Season - The 4 seasons in an ecosystem are very different, and this is because less light and heat is available from the sun in Winter and vice versa for Summer, therefore these varying conditions will affect which organisms are suited to them. Location - The extreme latitudes receive 6 months of sunlight and 6 months of darkness, while the equator receives roughly 12 hours of sunlight and darkness each day. This sort of variance greatly affects what type of organisms would occupy freshwater ecosystems due to these differences. Altitude - For every one thousand metres above sea level, average temperature drops by one degree Celsius. Altitude will also affect the aspect of which sunlight hits the freshwater ecosystem, therefore playing a part on which organisms will occupy it. As you can see, many abiotic factors can play a part in determining the end product, which organisms live and succeed in the freshwater ecosystem. The sun provides light for photosynthesis, but also provides heat giving a suitable temperature for organisms to thrive in. The temperature of a freshwater environment can directly affect the environment as a whole and the organisms that occupy it. Enzymes operate best at an optimum temperature, and any deviation from this temperature 'norm' will result in below optimum respiration in the organism. All aquatic life are ectotherms, meaning their body temperature varies directly with its environments.

4 Organism—individual living thing
Species—group of organisms that are closely related and can mate to produce offspring. Population—all the members of the same species that live in the same place at the same time Community—a group of various species that live in the saqqme place and interact with each other Habitat--the place an organism lives

5 What is Evolution? In the biological sciences, evolution is a scientific theory that explains the emergence of new varieties of living things in the past and in the present; it is not a "theory of origins" about how life began.

6 —Charles Darwin from "The Origin of Species"
Used by permission of Darwin Day Celebration (at DarwinDay.org), 2006 I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection.   —Charles Darwin from "The Origin of Species" Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

7 Isn’t evolution only a theory?
A scientific theory is a framework that guides research, not an idle speculation or a “hunch.” These theories are systematic, well-tested explanations that account for a broad range of observations. Biological evolution is a scientific theory that explains the pattern and process of variation and similarity among living things in terms of the common ancestry of living organisms. It is a widely accepted and applied theory because it continues to guide useful research and answer new questions even after 140 years

8 Three important concepts within evolutionary biology:
the definition of evolution (common ancestry and descent with modification) the processes of evolutionary change (for example, natural selection and genetic drift) The patterns of evolutionary relationships (depicted as phylogenetic trees).

9 Tree of Life

10 Tree of Life phylogeny, the ascent of all species through time,

11 Root of the Tree

12 The "archaea tree": The "eocyte tree":

13 EVIDENCE OF EVOLUTION STRUCTURAL ADAPTATIONS MIMICRY CAMOUFLAGE
Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

14 What Is It? Describe this specimen. What do you observe?
Describe this specimen. What do you observe? Is this a terrestrial or marine animal? What anatomical features support your hypothesis? Is this a modern or ancient animal? If ancient, what modern day animal does it resemble?

15 OTHER EVIDENCE OF EVOLUTION
FOSSILS ANATOMY HOMOLOGOUS STRUCTURES Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

16 OTHER EVIDENCE OF EVOLUTION
FOSSILS ANATOMY HOMOLOGOUS STRUCTURES ANALOGOUS STRUCTURES Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

17 OTHER EVIDENCE OF EVOLUTION
FOSSILS ANATOMY HOMOLOGOUS STRUCTURES ANALOGOUS STRUCTURES VESTIGIAL STRUCTURE EMBRYOS WHAT IS ANOTHER EXAMPLE OF VESTIGIAL STRUCTURES? Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

18 OTHER EVIDENCE OF EVOLUTION
FOSSILS ANATOMY HOMOLOGOUS STRUCTURES ANALOGOUS STRUCTURES VESTIGIAL STRUCTURE EMBRYOS BIOCHEMISTRY WHAT 2 THINGS? Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

19 WHAT IS SPECIATION? GEOGRAPHIC ISOLATION REPRODUCTIVE ISOLATION
Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

20 ADAPTIVE RADIATION – AN EXAMPLE OF DIVERGENT EVOLUTION
Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

21 Evolution Natural Selection Adaptation Artificial Selection
Evolution of Resistance

22 Natural Selection Over many generations natural selection causes the characteristics of populations to change. Darwin and Fossils --remains of extinct species from which modern species evolved.

23 NATURAL SELECTION Organisms produce more offspring than can survive
Environment is Hostile and contains limited resources Some inherited traits provide organisms with an advantage Each generation contains proportionately more organisms with advantageous traits

24 Traits were the Key Organism produce more offspring than can survive.
Result: periods of more diversity if more food

25 Environment is Hostile
Environment contains things and situations that can kill organisms, and the resources needed to live, such as food and water, are limited. Name an example. Desert Environment has limited rain and range in temperature. Competition is high for available water and food so adaptations are made. Thorns instead of leaves, roots that give out a toxin to keep other plants from getting to close and using up all the water, sleeping by day and feeding by night.

26 Survival of the Fittest
What does this mean to you? The fittest is one that survives to pass its genes on, is the one most adapted to its current or changing environment. It doesn’t necessarily mean it has to fight to survive.

27 Organisms Differ in Traits
Resistance to disease Coloration Size And so on…. Zebra has stripes to help hide them in the tall grasses Tigers also have stripes to help in hiding. Owels have head that go almost 360 degree turns in order to hear and see better. Fish form schools for protection Deer that once lived in warm climate developed thicker fur in order to survive in colder climates Bird has long beak to get termites out of dens Butterfly coloration makes it look bigger than it is to warn off predators

28 Inherited Traits are an Advantage
Coping with Environmental Challenges “naturally selected for” Survive longer and produce more offspring

29 change to distribution of traits
directional selection (favors phenotypes at one extreme) stabilizing selection (favors intermediate phenotypes) disruptive selection (favors phenotypes at both extremes)

30 Each Generation contains proportionately more organisms
Trait changes show up in greater proportion of offspring than previous generations.

31 When is it a new Species? When a group of organisms are capable of interbreeding and producing fertile offspring based on similarity of DNA.

32 How does the genetic pool change?
MUTATION How does the genetic pool change? GENETIC DRIFT GENE FLOW - MIGRATION ALL IMAGES: Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

33 Adaptations Inherited trait that increases an organism’s chance of survival and reproduction in a certain environment.

34 Animals of the Prairie Adaptations
Honeybee creates food out of pollen and stores it to eat later. Fox has large ears to hear better and bushy tail for balance Prairie dogs burrow in ground for safety Badger has large claws for digging Bobcat has tufts on ears to pick up movement in wind which carries noises Eagle has fantastic eyesight and speed.

35 Darwin’s Finches Activity
Form Four groups for four different species of finch’s bills: A. Thin B. Medium C. Small and powerful D. Large and powerful Draw Cards to simulate food types Page 99 of text book Have students write their bill type on a nametag or index card. Assign a food to the four suits in a deck of cards and then assign a bill type to that food type (e.g. if you assigned nectar to spaces, the corresponding finch would have a thin bill). Write the suits (foods) and their corresponding bill types on the board. Tell students that there is an abundance of two food types, so you are stcking the deck to include more than two of the suits. Shuffle the deck and have each student draw one card. If the student draws the suit that corresponds to her or his bill type, then the student stays in the game (i.e. passes genes on to the next generation). In the following rounds, have each remaining student draw three cards for successful match in the previous round (successful individuals have thre successful offspring each round). Keep stacking the deck to simulate patterns of environmental change. At the end of the game, ask students if the surviving offpsing match the most abundant food sources. (large beaked finches might one day evolve smaller beaks if their environment favored smaller beaks for at least several years)

36 Adapted (civilized) Crops
Corn was once a grass (teosinte) Cotton Tomatoes Chili peppers Tobacco Pineapple Squash avocadoes

37 Coevolution Organisms that adapt to other organisms as well as to their physical environment. Bird developed a curved thin beak to reach nectar; flower developed to ensure pollen would get onto head as it sips nectar

38 Artificial Selection Selective breeding of organisms by humans for specific characteristics. Plants like roses are bred for coloration and shape. Horses are bred for speed, strength or size Different from ancestor the wolf (far bottom left photo) Dogs are also bred for speed (sled dogs); strength (rescue dogs); fashion trends (designer dogs) and perfection of bred (best of show)

39 Resistance Evolution Ability of one or more organisms to tolerate a particular chemical design to kill it. A. Billbug B. Sugar Cane Beetle Billbug eats corn seedlings Sugar Cane Beetle destroys the stalks

40 1. Insect pests are sprayed with an insecticide
1. Insect pests are sprayed with an insecticide. Only a few resistant ones survive. 2. The survivors pass on the trait for resistance to offspring. 3. When the same insecticide is used again, more insects survive.

41 Diversity of Living Things
Bacteria Fungi Protists Plants Animals Bacteria--The Bacteria [bækˈtɪr.i.ə] (help·info) (singular: bacterium) are a large group of unicellular microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals. (The name comes from the Greek baktērion, meaning small staff.) Bacteria are ubiquitous in every habitat on Earth, growing in soil, acidic hot springs, radioactive waste,[1] water, and deep in the Earth's crust, as well as in organic matter and the live bodies of plants and animals. There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water; in all, there are approximately five nonillion (5×1030) bacteria on Earth,[2] forming much of the world's biomass.[3] Bacteria are vital in recycling nutrients, with many important steps in nutrient cycles depending on these organisms, such as the fixation of nitrogen from the atmosphere and putrefaction. However, most bacteria have not been characterized, and only about half of the phyla of bacteria have species that can be cultured in the laboratory.[4] The study of bacteria is known as bacteriology, a branch of microbiology. FungusA fungus (pronounced /ˈfʌŋgəs/) is a eukaryotic organism that is a member of the kingdom Fungi (pronounced /ˈfʌndʒaɪ/).[2] The fungi are heterotrophic organisms possessing a chitinous cell wall. The majority of species grow as multicellular filaments called hyphae forming a mycelium; some fungal species also grow as single cells. Sexual and asexual reproduction of the fungi is commonly via spores, often produced on specialized structures or in fruiting bodies Protists (IPA: /ˈproʊtɨst/), are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista but this group is no longer recognized in modern taxonomy.[1] The protists do not have much in common besides a relatively simple organization -- either they are unicellular, or they are multicellular without specialized tissues. This simple cellular organization distinguishes the protists from other eukaryotes, such as fungi, animals and plants.

42 Bacteria Archaebacteria—live in harsh environments like hot springs
Eubacteria—very common throughout terrestrial and aquatic environments.

43 Fungus All fungi absorb their food (after breaking it down chemically) from their surroundings. Some fungi causes diseases (Athlete’s foot) Other fungi add flavor to food (blue cheese or yeast to produce gas to make bread rise)

44 Protists either they are unicellular, or they are multicellular without specialized tissues. This simple cellular organization distinguishes the protists from other eukaryotes, such as fungi, animals and plants.

45 Plants Gymnosperms “naked sperm”—evergreens
woody plants whose sees are not enclosed in fruits. Angiosperms “vessel seed”—most plants flowering plants that produce seeds in fruit

46 Angiosperm Challenge Get into groups of four (4) people
At the signal, you have three minutes to write down everything that is a product of an angiosperm.

47 Animals Invertebrates-lack backbones
Vertebrates-amphibians, reptiles, birds, mammals

48 Insects More insects exist on Earth than any other animal
Successful because…. Have waterproof external skeleton Small size means less food needed Reproduce quickly Move quickly


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