1. Unit 7: Evolution and Classification

2. Opening Assignment
What is evolution?
What is an adaptation?

3. Charles Darwin 19th century English naturalist
developed a theory on how evolution works
studied on the Galapagos Islands because each island had different environments
wrote On the Origin of Species

4. Darwin’s Theory Species evolve from a common ancestor
Variation – slight difference in an inherited trait of individual members of a species
occurs as a result of mutations during sexual reproduction

5. Natural Selection "Survival of the Fittest”
organisms with variations that help them survive, live longer and are therefore able to reproduce to pass on those variations
ex. tortoises with longer necks will survive longer than tortoises with short necks if the food sources are up high

6. Adaptations
an inherited trait that increases an organism’s chance of surviving and reproducing in its environment

7. 3 Types of Adaptations Structural – involve physical characteristics
ex. coloration, shape
Behavioral – involves the way an organism acts
ex. hunting at night, moving in herds
Functional – involve internal body systems
ex. hibernation, temperature regulation

8. Environmental Interactions
Camouflage
Mimicry
an adaptation that enables a species to blend in with its environment
the resemblance of one species to another species

9. What is our evidence of Evolution?

10. Comparative Anatomy
the study of similarities and differences among structures of living species
Homologous Structures – body parts of organisms that are similar in structure, but different in function

11. Analogous Structures - body parts that perform a similar function, but differ in structure
ex. bird wings and insect wings

12. Vestigial Structures
body parts that have lost their original function through evolution
shows that the structures served a purpose at one point, but now are no longer needed
ex. cormorant wings, whale pelvic bones

13. Developmental Biology
Embryology – study of embryos from fertilization to birth

14. Molecular Biology
Scientists can use DNA to show how closely related organisms are
Divergence – the point at which an organism breaks away from its common ancestor

15. The Fossil Record
The Fossil Record – made up of all the fossils ever discovered on Earth
provides evidence that species have changed over time
Fossil – the remains or evidence of once-living organisms

16. Fossil Formation Mineralization Carbonization
minerals in water replace the organism’s original material and harden into rock
Carbonization
extreme pressure drives off the organism’s liquids and gases leaving only the carbon outline

17. Fossil Formation Molds and Casts
Mold – impression of an organism in hardened mud or sand
Cast – a fossil copy of an organism in a rock created by sediment filling in the mold

18. Fossil Formation Trace Fossils Original Material
preserved evidence of the organism’s activity, like footprints
Original Material
original tissues of an organism, like insects in amber (tree sap)

19. Relative-Age vs. Absolute-Age
Relative-Age – scientists determine the relative order in which rock layers were deposited( Most Accurate when the rock layers are undisturbed.)
Law of Superposition – things on the top are the youngest and things on the bottom are the oldest.
Absolute-Age (Radioactive Dating)– scientists use the ratio of unstable isotopes to stable isotopes to find the age of rocks; more precise
ex. carbon-14 dating
Add these to notes 

21. The Geologic Time Scale
a chart that divides Earth’s history into different time units

22. Extinctions
Extinction – occurs when last individual organism of a species dies
Mass Extinction
when many species become extinct within a few million years or less
there have been 5 mass extinctions in the Phanerozoic eon
Causes of Extinction
Sudden change – like meteor impact or volcanic eruption
Gradual change – like tectonic plates or sea level changes

23. Biological Evolution
the change over time in populations of related organisms

24. The immediate ancestors of humans were members of the genus Australopithecus .  The australopithecines (or australopiths) were intermediate between apes and people.  Both australopithecines and humans are biologically similar enough to be classified as members of the same biological tribe--the Hominini .  All people, past and present, along with the australopithecines are hominins .  We share in common not only the fact that we evolved from the same ape ancestors in Africa but that both genera are habitually bipedal , or two-footed, upright walkers.  By comparison, chimpanzees, bonobos, and gorillas are primarily quadrupedal , or four-footed. 

25. The Common Ancestor https://www.youtube.com/watch?v=HphLBNGCBNk
Evidence of Evolution

26. Which of the following correctly describes the general trend in hominid evolution?
larger body size, broad forehead, smaller brains
increase in brain capacity, bipedalism, use of tools
thickening of the skull, protruding teeth, organized hunting
large canine teeth, small skulls, diet of coarse plant material B

27. It shows that organisms have changed gradually over millions of years.
Biogeography is the study of the location of organisms around the world. Which of the following best explains how biogeography can provide evidence for evolution?
It shows that organisms have structures that serve no purpose but that resemble structural roles in related organisms.
It shows that there are similarities and differences among the DNA of different species.
It shows that organisms have changed gradually over millions of years.
It shows that some organisms that are unrelated have developed similar adaptations to similar environments. D

28. In his trips to the Galapagos Islands, Charles Darwin observed that 4 of the 13 species of the islands' finches have beaks adapted to eating specific foods. Which best explains how these facts provide evidence for divergent evolution?
The finches were different species but resemble each other because of how they evolved in a similar environment.
The finches descended from similar ancestors and have evolved adaptations in response to each other's influences.
The finches descended from the same ancestor but evolved along their own lines in isolation from each other.
The finches descended from a common ancestor but evolved differently in response to their environment. D

29. The Evolution Of Humans

30. Opening Assignment Why do scientists classify things?
What are the 8 levels of classification?

31. Classifying Organisms
Unit 7 – Evolution and Classification Part 2

32. Aristotle placed all organisms into 2 large groups-
Classification- putting things into groups based on shared characteristics
There have been many different ideas about how to classify living things.
Aristotle placed all organisms into 2 large groups-
plants and animals

33. Linnaeus’ System Linnaeus founded modern taxonomy.
Taxonomy- the science of describing , classifying , and naming living things
Based on 7 hierarchical categories
Simplified the naming of living things by giving each species a two-part specific name “Binomial nomenclature”

34. Binomial Nomenclature
Genus
Species
Felis domesticus
In a scientific name, the first part of the name is the organism’s genus. Similar species are grouped into one genus. Ex: Felis
The second part of the name identifies the species- a group of organisms that have similar traits and are able to produce fertile offspring.

35. Binomial Nomenclature
Panthera tigris
Panthera leo

36. Classification Today
Taxonomists use an eight-level system to classify living things based on shared characteristics.
The more characteristics the organisms share, the more closely related the organisms may be.

37. Levels Of Classification
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

39. DOMAINS Archaea Bacteria Eukarya
Every living thing is classified into one of the 3 Domains:
Archaea
Bacteria
Eukarya

40. DOMAIN 1: ARCHAEA ARCHAEBACTERIA Unicellular prokaryotes
Often live in harsh environments
some produce food by chemosynthesis (energy obtained from places other than the sun)

41. DOMAIN 3: EUKARYA EUKARYOTES
Complex cells; nuclei and organelles in cells
Some are unicellular
Some are multicellular
The domain Eukarya is divided into 4 Kingdoms:
Protista
Fungi
Plantae
Animalia

42. Domain Eukarya: Kingdom Protista
One celled or Multicellular organisms that can either be plant-like, animal like, or both
Algae, Amoebas, Paramecium , Euglena

43. Domain Eukarya: Kingdom Fungi
Multicellular
Cell wall
Does not perform photosynthesis
Absorbs nutrients
Reproduce using spores.

44. Domain Eukarya: Kingdom Plantae
Cell wall
Perform photosynthesis
Vascular vs. nonvascular
Flowering vs. nonflowering

45. Domain Eukarya: Kingdom Animalia
Multi-cellular organisms that lack cell walls
Range from simple to complex
Invertebrates- Do not have a backbone
Worms
Sponges
Jelly Fish
Mollusks
Insects
Vertebrates – Have a backbone
Fish
Amphibians
Reptiles
Birds
Mammals

47. Classification Tools

48. Dichotomous Key
A series of descriptions arranged in pairs that can be used to identify an unknown organism
The chosen descriptions leads to another pair of descriptions or to the identification of the organism

49. Dichotomous Key

50. Cladogram
A branched diagram that shows the relationships among organisms
New characteristics appear before each branch