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Learning Targets Determine absolute age using radioactive decay.

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Presentation on theme: "Learning Targets Determine absolute age using radioactive decay."— Presentation transcript:

1 Learning Targets Determine absolute age using radioactive decay.

2 DO NOW MONDAY What is biodiversity?
Why do you think it is important to learn about biodiversity?

3 Learning Targets Define biodiversity.

4 Which do you like better?
A B

5 Which do you like better?
A B

6 Which do you like better?
A B

7 Which do you like better?
A B

8 Which do you like better?
A B

9 What is biodiversity? -the variety of life across all ecological levels of organization

10 Biodiversity includes:
Genetic diversity: differences in DNA among individuals/species Species diversity: # or variety of species in a given area Ecosystem diversity: variety of ecosystems/habitats/communities

11 Species Diversity Most commonly used measure of biodiversity in an area Occurs through speciation: process by which new species are generated- happens over a long period of time Extinction DECREASES species diversity

12 Genetic Diversity Differences in DNA due to mutations, sexual reproduction, etc. Provides the raw material for evolution (adaptations) Reduced genetic diversity means reduced ability to adapt to environmental change and reduced ability to survive. More genetic diversity means a population has a better chance of evolving to survive an ever-changing environment

13 DO NOW TUESDAY Explain how genetic diversity affects a population’s ability to survive a changing environment.

14 Learning Targets Explain Darwin’s hypothesis for differences between similar species. Define natural selection. Explain how natural selection leads to evolution.

15 Why is biodiversity important?
Species are interconnected- they depend upon one another- we depend upon them

16 Why is biodiversity important?
Diversity is important to species and population survival Example: Northern Elephant seals hunted almost to extinction. Now their population has rebounded due to laws being passed, but they still lack genetic diversity. Why is this such a concern?

17 Why is biodiversity important?
Medical, industrial, and agricultural uses ¼ of all drugs come from plants and almost all antibiotics come from fungi Many compounds used for industry come from plants and animals All human food comes from other living things

18 Why is biodiversity important?
Ethics, aesthetics Many believe all organisms have a right to survive Make the world a pretty and more enjoyable place to live ecotourism

19 Video Biological Evolution
Watch video closely and complete handout as you watch.

20 What is Evolution Means “change over time”
Biological evolution means a change in a populations gene pool over time. A populations gene pool includes all of the genes that are present in the population.

21 Darwin’s Observations
December 1831, Charles Darwin set sail from England on a five year trip around the world. He observed plants and animals he had never seen before. This observation led him to develop the theory of evolution by natural selection.

22 Darwin’s Observations
Darwin’s observations included: Species diversity- lots of different species of organisms on different islands of the Galapagos (Ex. Finches) Species: a group of similar organisms that can mate with each other and produce fertile offspring Remains of ancient organisms (fossils)

23 Fossils

24 Galapagos Organisms Darwin’s drawings
Identify some specific differences in these finches’ beaks. These finches live on different islands in the Galapagos. Different islands have different food sources available to the finches

25 Evolution Darwin reasoned that plants or animals that arrived on the Galapagos Islands faced environmental factors that were different from those on the mainland. Darwin hypothesized that the species gradually changed (evolution) over many generations and became better adapted to the new environments.

26 Scientific theory Scientific theory: A well-tested concept that explains a wide range of observations Darwin concluded that organisms on the Galapagos Islands had changed over time, but did not know HOW the changes had happened.

27 Selective Breeding Humans have used selective breeding to produce sheep and pigeons that fit certain criteria. Darwin thought that a process similar to selective breeding might happen in nature.. But what process would push this selective breeding in nature?

28 Natural Selection Darwin proposed that evolution occurs in nature through natural selection (individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species) in the book called, On the Origin of Species by Natural Selection.

29 Natural Selection Competition – since food and other resources are limited, the members of a species must compete with each other to survive. Selection – some variations make individuals better adapted to their environment, making them better competitors and more likely to survive and reproduce

30 Natural Selection Selection (cont’d) – Darwin proposed that, over a long time, natural selection can lead to change. Helpful variations may gradually accumulate in a species, while unfavorable ones may disappear.

31 Adaptations a trait that makes an organism a better competitor and helps an organism survive and reproduce in its environment Ex: milkweed – poisonous or have a bad taste – avoid being eaten Ex: some plants have bright colored flowers – attract insects

32 Evolution Online A demonstration...

33 DO NOW THURSDAY What adaptations do you see in the pictures below? A)

34 Learning Targets Explain Darwin’s hypothesis for differences between similar species. Define natural selection. Explain how natural selection leads to evolution.

35 Darwin’s Theory of Natural Selection occurs in four steps:
Overproduction Variation Competition Selection

36 1. Overproduction Each species produces more offspring than can survive

37 2. Variation Each individual has a unique combination of inherited traits. Adaptation: an inherited trait that increases an organism’s chances of survival and reproduction in its environment

38 Why is Variation Important?
Because the environment changes. The more variation (diversity) within a species, the more likely it will survive EX: If everyone is the same, they are all vulnerable to the same environmental changes or diseases The more variation (diversity) of types of species in a habitat, the more likely at least some will survive EX: Dinosaurs replaced by mammals

39 Which community has a better chance of surviving a natural disaster?
Community A Community B

40 3. Competition Fitness: the ability to survive and reproduce
Individuals COMPETE for limited resources: Food, water, space, mates Natural selection occurs through “Survival of the fittest” Fitness: the ability to survive and reproduce Not all individuals survive to adulthood

41 4. Natural Selection The individuals with the best traits / adaptations will survive and have the opportunity to pass on it’s traits to offspring (reproduce). Natural selection acts on the phenotype (physical appearance), not the genotype (genetic makeup) Ex: When a predator finds its prey, it is due to the prey’s physical characteristics, like color or slow speed, not the alleles (BB, Bb)

42 Charles Darwin Game of Evolution

43 DO NOW WEDNESDAY How does embryo development serve as evidence for evolution?

44 Learning Targets Recognize pictorial data patterns of embryological development across multiple species. Describe how the fossil record documents the existence, diversity, and change of life forms. Identify anatomical similarities and differences between modern and fossil organisms. Identify anatomical similarities and differences in modern organisms. Define and identify homologous structures.

45 Evidence for Evolution:
Embryology Fossil Record Homologous Body Structures Vestigial Organs Biochemical Evidence

46 Embryology Embryology: embryos of all vertebrates are very similar early on

47

48 The Fossil Record Fossils: a record of the history of life on Earth

49 Archaeopteryx Transition species
Missing link between reptiles and birds

50 Fossils of organisms found on many different continents prove that all of the continents used to be joined at some point in the past. (Pangea)

51 Homologous Body Structures
Homologous Body Structures: similar anatomy in different types of animals because of common ancestor Example: forearm bones of human, bat, bird, dolphin

52 Homologous Body Structures

53 Vestigial Organs Vestigial Organs: “leftover” traces of evolution that serve no purpose

54

55 Biochemical Evidence Biochemistry: DNA with more similar sequences suggest species are more closely related EX: Humans and chimpanzees share more than 98% of identical DNA sequences

56 DO NOW THURSDAY What are homologous structures? Give an example.

57 Learning Targets 4.1 Identify a mold and cast fossil.
4.2 Identify a trace fossil. 4.3 Identify a petrified fossil. 4.4 Identify preserved remains. 4.5 Identify carbon film fossils. 5.1 Explain relative dating using index fossils. 5.2 Identify the sequence of rock layers using the Law of Superposition. 5.3 Determine the absolute age of fossils/rock layers using radioactive decay/half-life. 6.1 Define biodiversity. 6.2 and 6.3 Identify anatomical similarities and differences in modern organisms. 7.1 Describe how the fossil record documents the existence, diversity, and change of life forms. Define natural selection. Explain how natural selection leads to evolution. Explain Darwin’s hypothesis for differences between similar species. Identify anatomical similarities and differences between modern and fossil organisms. Recognize pictorial data patterns of embryological development across multiple species. Define and identify homologous structures.

58 What is the adaptation? Milk Snake (Not poisonous) Coral Snake (Poisonous)

59 What is the adaptation?

60 What is the adaptation?

61 What is the adaptation?

62 What is the adaptation?

63 What is the adaptation? Stick Mantid

64 What is the adaptation? Flower Mantid


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