Evolution and Biodiversity Unit 4

1. 0 Evolution and Biodiversity Unit 4

2. 0 The theory of evolution... You have researched the different theories of evolution…. • Scientists view on evolution has changed over the years. We currently use Darwin’s theory because it is best supported by current science. • Evolution is called a theory because our view is static- it is constantly being modified based on new information we learn through science.

3. 0 The theory of evolution... There are two divisions in the theory of evolution…. • Macroevolution is accepted by most- it is based on the theory of natural selection- where the most fit organisms survive and pass their traits to their offspring. • Microevolution is the more controversial. It involves organisms evolving into new species.

4. 0 Natural Selection... • All organisms have the ability to produce more offspring than can survive. • Natural Selection is a “check” to control overpopulation, so those organisms that are less fit will not survive.

5. 0 Natural Selection... • Organisms produce more offspring than can survive: • Less fit offspring will not survive

6. 0 Natural Selection... • Abiotic Factors affect Natural Selection: • Limiting Factors (resources that can run out eventually) affect what organisms can live in an area… • Natural selection is affected by this, more fit organisms • survive those conditions and reproduce while the others die from a lack of that resource. • Competition for the resources affects the number of organisms that can survive.

7. 0 Natural Selection... • Organisms produce more offspring than can survive: • Less fit offspring will not survive • Abiotic Factors influence natural selection: • Limiting factors determine what organisms can survive. • Organisms that can out-compete for resources will survive and pass on their traits (survival of the fittest)

8. 0 Natural Selection... • Individuals differ in their traits genetically. • Genetic variations influence natural selection. • New variations are caused by genetic mutations. • Genetic mutations either positively or negatively influence natural selection. • Changes that cause evolution are ALWAYS inherited…they never occur within one organisms’ lifetime.

9. 0 Natural Selection... • Organisms produce more offspring than can survive: • Less fit offspring will not survive • Abiotic Factors influence natural selection: • Limiting factors determine what organisms can survive. • Traits vary based on an individual’s genetics • Mutations cause variation- if it helps the organism they survive and pass the trait on to their offspring; variations are always inherited

10. 0 Natural Selection... • Some traits give individuals advantages over their current environment. • They help them survive against environmental challenges • They allow them to produce more offspring • These traits are “naturally selected” • They are determined by the SELECTIVE AGENT= the biotic or abiotic factor that is choosing what type of species survives and what species dies • Example: peppered moth was selected by birds that could see them against the trees.

11. 0 Natural Selection... • Abiotic Factors influence natural selection: • Limiting factors determine what organisms can survive. • Traits vary based on an individual’s genetics • Mutations cause variation; variations are always inherited • Organisms with traits that are better adapted to the environment survive and pass them on to offspring • Selective agents determines the traits that are most fit. • example: the limiting resource

12. 0 Natural Selection... • Natural selection causes evolution to occur: • Offspring with the better adaptations tend to have more offspring, which in turn have more offspring… • Over many generations, the adaptation becomes standard= evolution

13. 0 Natural Selection... • Organisms have traits that are better adapted to the environment • Selective agents choose the traits that are most fit. • Natural selection causes evolution • Better traits are passed along from generation to generation. When most of the population has that trait the species has evolved.

14. Natural Selection... • Is a theory because: • The two types of evolution are: • _________________________ (natural selection / survival of the fittest) • and ______________________________ (evolution of species). • Organisms produce more offspring than can survive: • * • Abiotic Factors influence natural selection: • * • * • Traits vary based on an individual’s genetics • * • Organisms with traits that are better adapted to the environment survive and pass them on to offspring • * • Natural selection causes evolution • *

15. Biodiversity 0 Review: What is the definition of a species? • How many species are there? • To date there are about 1.8 million species that have been scientifically named and described. • There are thought to be many more undiscovered (about 5 million to 100 million) • There are 10,000 new species found each year. It is impossible to know how many there are… • 70% of newly discovered species are insects.

16. Biodiversity 0 • Species: definition: an organisms that can mate and produce fertile offspring • discovery: Every year about 10,000 new species (mostly insects) are discovered, there is estimated 5-100 million species total, but • we know of only 1.8 million. • Biodiversity has three parts: • Species diversity: • Genetic diversity: • Ecosystem diversity:

17. What does diversity mean in a general sense?

18. Biodiversity 0 • Organisms can be diverse in 3 ways: • Species Diversity: the variation among organisms • Example- Dogs are all part of the same species but they look different based on the environment they were breed in.

19. Biodiversity 0 • Species: definition: an organisms that can mate and produce fertile offspring • discovery: Every year about 10,000 new species (mostly insects) are discovered, there is estimated 5-100 million species total, but • we know of only 1.8 million. • Biodiversity has three parts: • Species diversity: the variation among organisms of the same species • Genetic diversity: • Ecosystem diversity:

20. What makes us all different?

21. Biodiversity 0 • 2. Genetic Diversity: genetic variety within all populations of that species • Maintaining a broad genetic diversity is important. • It is critical for each species’ long-term health and survival. (Interbreeding allows hereditary diseases to emerge in individuals in a population.) • It provides us with a variety of genes to used in genetic engineering- has already become important in medicine

22. Biodiversity 0 • Species: definition: an organisms that can mate and produce fertile offspring • discovery: Every year about 10,000 new species (mostly insects) are discovered, there is estimated 5-100 million species total, but • we know of only 1.8 million. • Biodiversity has three parts: • Species diversity: the variation among organisms • Genetic diversity:genetic variety within all populations of that species • Ecosystem diversity:

23. Biodiversity 0 • Ecosystem Diversity: the variety of interactions among organisms in natural communities • Example: A forest community has greater ecosystem diversity than a cornfield does.

24. Biodiversity 0 • Species: definition: an organisms that can mate and produce fertile offspring • discovery: Every year about 10,000 new species (mostly insects) are discovered, there is estimated 5-100 million species total, but • we know of only 1.8 million. • Biodiversity has three parts: • Species diversity: the variation among organisms • Genetic diversity:genetic variety within all populations of that species • Ecosystem diversity: the variety of interactions among organisms in natural communities

25. Biodiversity 0 • Species: definition: • discovery: • Biodiversity has three parts: • Species diversity: • Genetic diversity: • Ecosystem diversity:

26. Biodiversity 0 • Why do we need organisms? • Other species make important contributions to our survival: • We depend on them for medicine: 40% of your medicine comes from plants • Future medicine could be found in species of plants that are still not discovered • Example: Rosy periwinkle makes chemicals that fight cancer. It’s chemical has increased the survival rate for childhood leukemia from 5% to 95%!

27. Biodiversity 0 • Biodiversity has three parts: • Species diversity: the variation among organisms • Genetic diversity:genetic variety within all populations of that species • Ecosystem diversity: the variety of interactions among organisms in natural communities Organisms are important for: 1. Medicine (40% comes from plants) 2. 3. 4. 5.

28. Biodiversity 0 • We use them for food: • Human population relies on just three staple plants (rice, corn, and wheat) for over half of it’s food supply • Wild food crops could become new staples, or crossed with present food crops to produce new strains that are resistant to disease or insects • We also use organisms for economic needs such as: • clothing (wool, cotton, silk) and shelter (wood)

29. Biodiversity 0 • Biodiversity has three parts: • Species diversity: the variation among organisms • Genetic diversity:genetic variety within all populations of that species • Ecosystem diversity: the variety of interactions among organisms in natural communities Organisms are important for: 1. Medicine (40% comes from plants) 2. Food: half our food supply comes from rice, wheat and corn 3. Clothing (wool, cotton, silk) 4. Shelter (wood) 5.

30. Biodiversity 0 • Insects pollinate crops, help in weed control & in insect pest control • Bacteria and fungi provide us with foods (yogurt, cheese), medicine (antibiotics) and services such as nitrogen fixation (for healthy plants) Read p. 373 2nd column, 1st full paragraph: list 7-8 things plants supply us with and 7-8 things animals supply us with.

31. Biodiversity 0 Organisms are important for: 1. Medicine (40% comes from plants) 2. Food: half our food supply comes from rice, wheat and corn 3. Clothing (wool, cotton, silk) 4. Shelter (wood) 5. Crop control- pollination and pest management

32. Biodiversity 0 • Diverse ecosystems provide Ecosystem services which are important environmental functions that organisms within ecosystems provide. All species are interrelated, including humans, and are completely dependent on these basic support services: • Forests provide lumber • Watersheds provide drinking water, reduce flooding & prevent erosion • Determine the shape and health of the environment

33. Biodiversity 0 Organisms are important for: 1. Medicine (40% comes from plants) 2. Food: half our food supply comes from rice, wheat and corn 3. Clothing (wool, cotton, silk) 4. Shelter (wood) 5. Crop control- pollination and pest management Ecosystem services: When humans depend on the environment for basic survival needs. Ex: lumber (forests) and drinking water (watersheds) Keystone species:

34. Biodiversity 0 Predict what happens when you remove a species from its environment. If you remove too many species what will happen? Some species are so important to the functioning of the ecosystems that the whole ecosystem would collapse if they disappeared: Keystone species

35. Biodiversity 0 Ecosystem services: When humans depend on the environment for basic survival needs. Ex: lumber (forests) and drinking water (watersheds) Keystone species: Species that are essential, if gone the entire ecosystem would collapse.

36. Biodiversity 0 • Organisms provide recreation, inspiration, and spiritual solace. • Tell me what you think: • Are humans really superior beings, free to exploit other life forms for our benefit? Or, are we stewards of the life forms on Earth, responsible for watching over them and protecting their existence? Explain why you think this…

37. 0 Extinctions: Then and Now Plant and animal species are disappearing at least 1000 times faster than any time within the last 65 million years (since the last mass extinction). And 100 times faster than background species extinctions (low levels of extinction over time). By 2100, 25% of all species that lived on Earth in 1900 will be gone!

38. 0 Extinctions: Then and Now Mass Extinction: animals disappear in high numbers in a short period of time. Background Extinction: gradual disappearance of species over long periods of time. Characteristics that promote species extinctions: 1. 2. 3. 4. 5. 6. Areas with the most endangered organisms:

39. 0 Extinctions: Then and Now • Characteristics that make some species more vulnerable to extinctions: • Small, localized range: Makes species particularly prone to extinction if habitat is altered. • Example: Tiburon Mariposa Lilly: found nowhere in nature except on a single hilltop in San Francisco.

40. 0 Extinctions: Then and Now Mass Extinction: animals disappear in high numbers in a short period of time. Background Extinction: gradual disappearance of species over long periods of time. Characteristics that promote species extinctions: 1. Small localized range: lives in only one specific area ex: Tiburon Mariposa Lily in San Francisco 2. 3. 4. 5. 6. Areas with the most endangered organisms:

41. 0 Extinctions: Then and Now • Large territories are required: Threatened when all or part of their territory is modified by humans • Example: The California Condor is a scavenger and needs hundreds of square miles to forage for food. It’s population reached a low of 22 birds in the late 1980’s and with conservation efforts it has increased to over 400.

42. 0 Extinctions: Then and Now Mass Extinction: animals disappear in high numbers in a short period of time. Background Extinction: gradual disappearance of species over long periods of time. Characteristics that promote species extinctions: 1. Small localized range: lives in only one specific area ex: Tiburon Mariposa Lily in San Francisco 2. Large territories required for feeding ex: California condor 3. 4. 5. 6. Areas with the most endangered organisms:

43. 0 Extinctions: Then and Now • Living on islands (or an isolated habitat such as a patch of forest surround by houses.) • Many island species are endemic (native) to certain islands • They are small populations which • evolved in isolation from competitors, • predators and disease so they have • few defense skills. • Can not be replaced by immigration • if numbers decrease • Example: Hawaiian silversword

44. 0 Extinctions: Then and Now Characteristics that promote species extinctions: 1. Small localized range: lives in only one specific area ex: Tiburon Mariposa Lily in San Francisco 2. Large territories required for feeding ex: California condor 3. Living on islands (isolated areas)- no defenses, most are endemic (native to the area) ex: Hawaiian silversword 4. 5. 6. Areas with the most endangered organisms:

45. 0 Extinctions: Then and Now • Low reproductive success: • If a population density and size fall below a certain minimum level for reproductive success, the population declines even further. • May happen due to low reproductive rates • Example: Blue Whale has only 1 calf every other year

46. 0 Extinctions: Then and Now Characteristics that promote species extinctions: 1. Small localized range: lives in only one specific area ex: Tiburon Mariposa Lily in San Francisco 2. Large territories required for feeding ex: California condor 3. Living on islands (isolated areas)- no defenses, most are endemic (native to the area) ex: Hawaiian silversword 4.Low reproductive success- low rates or young can’t survive ex: blue whale (1 calf every other year) 5. 6. Areas with the most endangered organisms:

47. 0 Extinctions: Then and Now • Specialized breeding areas • Habitat destruction or other human disturbances in these areas can disrupt breeding patterns • Example: Green Sea Turtle returns back to the beach where it hatched to lay eggs. The turtles, when hatched follow the moonlight into the ocean. People using the beach and lights from homes cause the baby’s to have trouble finding the water.

48. 0 Extinctions: Then and Now 3.Living on islands (isolated areas)- no defenses, most are endemic (native to the area) ex: Hawaiian silversword 4.Low reproductive success- low rates or young can’t survive ex: blue whale (1 calf every other year) 5. Specialized breeding areas, disrupted by humans. Ex: green sea turtle 6. Areas with the most endangered organisms:

49. 0 Extinctions: Then and Now • Specialized feeding habits: • Some animals only eat one type of food, limiting their ability to survive if that food source decreases • Example: Panda bears only eat Bamboo

50. 0 Extinctions: Then and Now 3.Living on islands (isolated areas)- no defenses, most are endemic (native to the area) ex: Hawaiian silversword 4.Low reproductive success- low rates or young can’t survive ex: blue whale (1 calf every other year) 5. Specialized breeding areas, disrupted by humans. Ex: green sea turtle 6. Specialized feeding habits ex: pandas only eat bamboo Areas with the most endangered organisms: