Chapter 4 – The organization of life

1. Chapter 4 – The organization of life Section 1 – Ecosystems: Everything is Connected

2. Defining an Ecosystem • Ecosystem: Communities of organisms and their surrounding environment • - oak forest or a coral reef • Ecosystems are connected • a. Do not have clear boundaries • b. Things move from one ecosystem to another • - Pollen can blow from a forest into a field • - Soil can wash from a mountain into a lake

3. Ecology • Ecology: the branch of biology that deals with the relations of organisms to one another and to their physical surroundings.

4. The Components of an Ecosystem • - Ecosystems need five basic components to survive: • 1. energy (most comes from the sun) • 2. mineral nutrients • 3. water • 4. oxygen • 5. living organisms. • - If one part of the ecosystem is destroyed or changes, the entire system is affected

5. Biotic and Abiotic Factors • - Biotic factors • - environmental factors that are living or once living organisms OR materials that come from organisms • - plants, animals, dead organisms, and their waste products • - Abiotic factors • - environmental factors that never were living organisms • - air, water, rocks, and temperature, etc.

6. Levels of Ecological Organization

7. Ecologists organize life into categories Organism: Living things that can carry out life processes independently. • -You are an organism, as is an ant, ivy plant, and each of the bacteria living in your intestines. • - Every organism is a member of a species. • -Speciesare groups of organisms that are closely related and can mate to produce fertile offspring. (Mating pair)

8. Ecologists organize life into categories • - Members of a species may not all live in the same place. Field mice in Maine will not interact with field mice in Texas • - Populations • - groups of organisms of the same species that live in a specific geographical area and interbreed. • - All the field mice in a corn field make up a population of field mice.

9. Ecologists organize life into categories • - Members of a population usually breed with one another rather than with members of other populations • - Bison will usually mate with another member of the same herd not other a member from another herd

10. Ecologists organize life into categories • Communities: Groups of various species that live in the same habitat and interact with each other • - Every population is part of a community • - The most obvious difference between communities is the types of species they have. • - Land communities are often dominated by plants species • - The plants determine what other organisms can live in that community

11. Ecologists organize life into categories • Habitat: Places where an organism usually lives • - Habitats have specific characteristics that the organisms living there need to survive • - If any of these factors change, the habitat changes • - Organisms tend to be very well suited to their natural habitats • - animals and plants usually cannot survive for long periods of time away from their natural habitat

12. Ecologists organize life into categories • Ecosystem: Communities of organisms and their surrounding environment • Biome: a large region with a similar climate and organisms • Biosphere: the regions of the surface, atmosphere, and hydrosphere of the earth occupied by life.

13. Critical Factors

14. Organism Research Project • Pick an Organism and research the following information about the organism: • Common Name, Scientific Name, Name of a group of your organism (ex: Group of lion = Pride, sault, or troop) • Other populations that interact with this species • Detailed description of natural Habitat (include some specific biotic and abiotic factors in description) • Regional location (be specific as possible) and Biome (include climate details) the organism is primarily located • Create a mini-poster with all of this information. Include a colored drawing of your organism in an example of it’s habitat.

15. -Turn in: Ecosystem Drawing and Organism Poster. -Get a Evolution Note handout. What do you think? What are some adaptations organisms have to hunt prey? What are some ways organisms defend for themselves from hunters? Chapter 4 – The organization of life Section 2 - Evolution

16. Charles Darwin • - Charles Darwin observed that organisms in a population differ slightly from each other in form (structure), function, and behavior • - Some of these differences are hereditary (get passed from parent to offspring) • - He proposed the environment exerts a strong influence over which individuals survive to produce offspring • - Some are more likely to survive and reproduce than other individuals because of certain traits

17. Evolution by Natural Selection • - Natural selection: individuals that have favorable traits and are better adapted to their environment. • -They survive and reproduce more successfully than less-adapted individuals • - Darwin proposed that over many generations, natural selection causes the characteristics of populations to change • - Evolution: change in the characteristics of a population from one generation to the next. AKA “decent with modification”

18. Nature Selects

19. Nature Selects • - Nature ‘selects’ for certain traits, such as sharper claws, because organisms with these traits are more likely to survive • - Over time, the population includes a greater and greater proportion of organisms with the beneficial trait • - As the populations of a given species change, so does the species.

20. NS = some of each SS = sickle cells NN = normal cells Sickle Cell Anemia • In the heterozygous condition, both alleles are expressed equally • Example: Sickle Cell Anemia in Humans sick http://www.youtube.com/watch?v=1fN7rOwDyMQ

21. Nature Selects • Adaptation: an inherited trait that increases an organism's chance of survival and reproduction in a certain environment • -Can be an Physical, Behavioral, or Physiological change that improves a population’s ability to • survive

22. Three Types of Adaptations • Physical Adaptations: some type of structural modification made to a part of the body. • Ex: webbed feet, sharp claws, fur. • Behavioral Adaptations: something an animal does (how it acts) usually in response to some type of external stimulus. • Ex: hibernation, mating dances, flying south for winter • Physiological Adaptations: the ability of the organism to perform special functions • Ex: venom production, temperature regulation, growth and development.

23. Darwin’s Four Premises • Overproduction – each species produces more offspring than will survive to maturity • Variation – individuals in a population have slightly different traits • Selection – individuals compete and the environment selects those with traits that help survival and reproduction • Adaptation of a Population/Successful Reproduction – beneficial traits become more common in the next generation

24. Coevolution • Coevolution: When two species evolve in response to long-term interactions with each other • - The Hawaiian honeycreeper has a long, curved beak to reach nectar at the base of a flower • - The flower has structures that ensure the bird gets some pollen on its head • - When the bird moves the next flower, some of the pollen will be transferred, helping the flower reproduce

25. Coevolution • - The honeycreeper’s adaptation is a long, curved beak. • - The plant has two adaptations: • - 1. the sweet nectar to attract the birds • - 2. the flower structure that forces pollen onto the bird’s head when it sips nectar

26. Newt vs. Snake

27. Man Selects • Artificial selection:selective breeding of organisms, by humans, for specific desirable characteristics. • - Dogs have been bred for certain characteristics • - Sporting, Hunting, Herding, Terriers, Working, etc. • - Fruits, grains, and vegetables are also produced by artificial selection. • - Humans save seeds from the largest, and sweetest fruits • - Farmers direct the evolution of crop plants to produce larger, sweeter fruit

28. Evolution of Resistance • Resistance: the ability of an organism to tolerate a chemical or disease-causing agent • - An organism may be resistant to a chemical when it contains a gene that allows it to break down a chemical into harmless substances • - Humans promote (encourage) the evolution of resistant populations by trying to control pests and bacteria with chemicals.

29. Evolution and Resistance • Pesticide and Corn: • -A pesticide is sprayed on corn to kill grasshoppers, may kill most of the grasshoppers, but some develop resistance • - The hoppers that survive could have a gene that protects them from the pesticide • - These surviving insects pass on this resistant gene to their offspring • - Each time the corn is sprayed, more resistant grasshoppers enter the population • - Eventually the entire population will be resistant, making the pesticide useless

30. Pesticide Resistance

31. Antibiotic Resistance Video • http://sixtyminutes.ninemsn.com.au/article.aspx?id=8615278 • http://abcnews.go.com/GMA/video/aimee-copeland-gma-interview-battle-flesh-eating-disease-17216238

32. Evidence for Evolution • Homologous Structures • Vestigial Structures • Biochemical Evidence

33. Homologous structures: Similar Structures in Different species suggest a common ancestor

35. Homologous Structures -Show descent with modification -Traits that are similar between different species have been inherited from a common ancestor

36. Vestigial Structures • traces of structures from ancestral species that serve no current useful function ex. Pelvic Bones in whales, appendix in Humans

37. Whale pelvic bones are vestigial

39. Example: Hand bones in a manatee

40. Comparing DNA • Biochemical Evidence: Shows DNA similarities and relatedness • The more DNA species have in common, the more closely related they are • Ex. Human and Chimp are about 98% same DNA

41. Convergent vs. Divergent • Convergent evolution • Different species produce similar adaptations • Divergent evolution • Similar species produce different adaptations

44. Darwin’s Finches