Paleo 200 Final

Final test

1. Carl Linnaeus

Founding father of taxonomy

• Introduced a new system for scientifically naming organisms

• 18th century dude

2. Taxonomy

The science of naming and organizing organisms into related groups

• prior to Linnaeus there was not system which led to considerable confusion regarding classifying organisms

• system is still used today

• organism is given a binomial name

3. Binomial Name

Consists of 2 parts 1.Genus name 2. specific epithet

• genus name is capitalized, specific epithet is not

• the binomial name is always italicized (or underlined if writing by hand) Ex / Homo sapiens /

4. Can a specific epithet be shared by species who are not closely related?

Yes! As long as the genus is different

• the specific combination of genus name and specific epithet are not permitted to be shared by any two species

5. The Rule of Priority

States that once a species has officially been given a binomial name, the named cannot be changed (unless it turns out that the organism is not really a new species)

6. How must a biologist officially give a new species a binomial name?

They must publish a description of the new species in a widely distributed and peer-reviewed scientific publication

• the published description must contain a list or combination of characteristics that makes the new species unique

7. Peer-reviewed Scientific Publication

Is one that is not published until it has been reviewed by other scientists to verify that the contents of the publication are legitimate and scientifically reasonable

8. Holotype

A specimen that is a physical example of the new species

• it must be kept at a research institution such as a university or museum such that other scientists may study it

• does not necessarily have to be a complete specimen (dinosaur holotypes are hardly ever complete)

• in case you were wondering, there is no /Homo sapiens/ holotype. I googled it

9. Just because 2 organisms look different are they separate species?

No! Individuals may differ morphologically due to intraspecific variation

10. Interspecific Variation

Individuals that differ in morphology because they be-long to different species

11. Instraspecfic Variation

Individuals who belong to the same species but have different morphologies Ex Tyler an Austin look different, but still belong to the same species

12. Four types of Intraspecific Variation

1. sexual dimorphism

2. ontogenetic variation

3. individual variation

4. taphonomic variation

13. Sexual Dimorphism

When males and females of the same species look different

14. Ontogenetic Variation

The variation that you can see between young and old individuals of the same species

15. Individual Variation

The normal variation that exists among individuals of any given species

16. Taphonomic Vartiation

Taphonomic process like plastic deformation can change the shape of a bone

17. Is there a single agreed upon definition of a species

No

18. The Biological Species Concept

Defines a species as a group of organisms that can successfully interbreed

• most common species concept

19. Where does the biological species concept fall short?

• organisms that reproduce asexually

• extinct organisms as we cannot observe breeding

20. Population

Is any grouping of organisms that live in the same geographic area and interbreed

• single species are often divided into separate groups by geographic barriers = popualtions

• one or more populations make up a species

21. The Morphological Species Concept

Defines a species as a group of organisms that share a certain degree of physical similarity

• this is the definition that paleontologies rely on

22. Where does the Morphological Species Concept fall short

when faced with intraspecific variation such as

• sexual dimorphism

• ontogenetic variation

23. Lumpers

Paleontologists who require more differences before they consider two species to be distinct

24. Splitters

Paleontologists who require fewer differences before they consider two species to be distinct

25. Hesperinychus

A dromeaosaurid theropod. The holotype for this species is housed at the University of Alberta

• but only the pelvis serves at the holotype

• small dinosaur but paleontologists knew it was not a juvenile as the pelvis bones were tightly fused (characteristic of adult bones)

26. Cryptic Species

Species that look similar but are not cable of interbreeding

27. Charles Darwin

First to propose the theory of evolution

• British naturalist

28. What did the theory of evolution explain?

• how new species came into existence

• how organisms adapted to their environment

• why specific organism shared certain traits

• all life on earth is related and shares a single common origin

29. Four main principles evolution is based on

1. Traits are heritable

2. Variation within a population

3. Variation of a trait must provide an advantage (differential success) over other variations

4. Competition --> these four principles lead to change (evolution) over time

30. Heritable

Means that the trait is part of an organisms genetic code and therefore has the chance to be copied to the organism offspring

31. Variation

Sometimes an organism has traits that are new and not copied from their parents

• potential source = random genetic mutation

32. Variation Advantage/Differential Success

The variation in a certain trait must provide an advantage for survival for an organism such that there is a better chance that the organism reproduces and passes on that trait to their offspring

33. Competition

There are limited resources and therefore there is competition for these resources that permits only some organism (the ones who obtain the resources) to successfully reproduce before they die

34. What happens if a lot of new variations arise/persist in a population?

A new species arises

• does not mean the ancestor will go extinct

• new species may simply branch off from its ancestor (maybe only a single population was exposed to a new environment that caused the evolution of many new traits)

35. Is evolution a random process?

No! Even though random mutation may constitute the variation that leads to evolution, the variation will only persist if it posses an advantage in the organisms environment and provides reproductive success(which is not a random process)

36. Natural Selection

The competitive selective process by which detrimental traits are competitively discarded and advantageous traits are retained

37. In taxonomy how are organisms group together?

Based on their most recent shared common ancestor

38. Character

Any heritable trait that can be described and labeled

39. Shared Derived Character/Synapomorphy

A character that is present in two or more groups and their common ancestor, but is not present in an distantly related groups

40. What is one of the biggest challenges in determining evolutionary relationships?

Convergent evolution

41. Convergent Evolution

The evolution of similar traits in two different lineages

• usually occurs when two linages must adapt similar environments and similar modes of life Ex the sail in Spinosaurus and Ouranosaurus

42. Parsimony/Occam's Razor

The simplest answer is usually the right one - always use parsimony when constructing a phylogenetic tree

44. Node

Where two branched diverge and shows the point at which two lineages share a common ancestor

45. Clade

A group of organism that share a common node

• a clade must contain the ancestor of a group and all its decedents

46. Does the Linnaean Hierarchy work well with our modern understanding of evolutionary relationships?

No, not really

47. Thomas Henry Huxley

A close colleague of Darwin and one of the earliest advocates of for the theory of evolution

• also the first scientist to recognize that birds evolved from dinosaurs

48. Archaeopteryx

Specimen that Thomas Henry Huxley designated as the 'miss-ing link" between birds and dinosaurs

49. Sinosauropteryx

Was the first non-avian (i.e. non-bird) dinosaur to be discov-ered with feathers

• specimen in which one of the most significant shared characteristics between dinosaurs and birds was found

50. Yutyrannus

Largest carnivorous dinosaur found with feathers

51. Which group of dinosaurs did birds evolve from

Theropods

52. Are we certain with our definition of what is a bird?

No! There are four contending definitions

43. Phylogenetic Tree

Diagrams of species organized based on their evolutionary relationships

• Scientists take various character traits of species, apply the principle of parsimony, and use a computer program to organize organisms in a sequence of relationships that requires the fewest instances of convergent evolution

• composed of nodes and branches

53.Four bird Definitions

1. Archaeopteryx and all of its descendants

2. Feathered Dinosaurs

3. 3.Flying Dinosaurs

4. 4.Crown Dinosaurs (the last common ancestor of all extent birds and its decedents)

54. Problem with Archaeopteryx and all of its descendants Definition

New phylogenetic analysis sometimes show that Archaeopteryx is more closely related to dromaeosaurid than to modern birds

55. Problem with Feathered Dinosaurs Definition

As more featured dinosaur fossil, like Yutyrannus, are found, more dinosaurs are included in this definition

• for example tyrannosaurus would not be considered a bird

56. Problem with Flying Dinosaurs Definition

It is difficult to determine exactly when dinosaurs were capable of flying (as opposed to simply gliding)

57. Problem with Crown Dinosaurs Definition

This definition fails to recognize many feathered and flying dinosaurs that are more closely related to modern birds than to Archaeopteryx as birds

• however this is the definition favoured by most paleontologists

58. In sedimentary rocks where are the oldest and youngest rocks?

• the oldest rocks are at the bottom

• the youngest rocks are at the top

59. The Principle of Superposition

the tendency for rock layers to be chronolog-ically stacked oldest layers and the bottom and newest layers at the top allows scientists to infer the relative age of rocks layer but not the absolute age

60. How do Igneous rocks affect stratigraphy?

They may vertically cut through horizontally arranged layers of rocks

61. How does the building of mountains affect stratigraphy?

They may tilt, fold, or even flip rocks layers

62. Stratigraphy

The science of using the arrangement and composition of rock layers to interpret geological history

63. A Formation

A large uninterrupted sequence of rock that is made of multiple layers that all share similar properties (such as mineral composition and average sediment grain size

64. What does a sequence of rock changing from formation to another indi-cate?

This indicates that a large scale change occurred in the environment where the rocks were being deposited

65. Isotope

Is a variant of a chemical element that has an unusual number of neutrons

66. Radiometric Dating

Method to determine the absolute age of rocks

• all matter is composed of chemical elements

• these chemical elements are atoms composed of a particular number of protons, electrons, and neutrons

• some of these chemical elements may exist as isotopes

• some isotopes are unstable and will undergo radioactive decay

• the time at which some isotopes undergo radioactive decay is a mathematically predictable rate

• as rocks age the isotopes decay

• using a mass spectrometer it is possible to measure the isotope ratio of a rock and this ratio can tell you how long ago a rock formed

67. Can sedimentary rock easily be radiometrically dated?

No. They are typi-cally composed of sediments that have already formed and were potentially already undergoing radioactive decay

68. Can igneous rocks easily be radiometrically dated?

Yes! As they are usually formed a new

69. How then do we date sedimentary rocks?

By combining radiometric dating and the principle of superposition

What is one of key tools in fossil dating?

Volcanic ash

The Geological Time Scale

A standardized series of chronological devisions that parses the Earth's history into discrete name units

70. Name the units in the time scale from largest to smallest (4 units)

1. Eons

2. Eras

3. Periods

4. Epochs

73. The Hadean Eon

• 4.6 - 4 BYA

• Earth was covered in molten and there was a lot of volcanic activity

• young earth collided with a smaller planetoid. This formed a lot of debris that was kept in by earth's gravity and eventually formed the moon

• by the end of the Hadean the earth had cooled and large oceans covered much of its surface

• complex organic molecules form in the early oceans (may be earth's earliest life forms)

74. How old are the oldest rocks on earth?

4.4 BYA

• rocks discovered on the moon are even older

75. The Archean Eon

• 4 - 2.5 BYA

• oldest known fossils come from this eon (are simple single-celled organisms)

• cyanobacteria evolves (were capable of photosynthesis)

• photosynthesis from cyanobacteria produced a lot of oxygen gas that became concentrated in earth's atmosphere

• some cyanobacteria formed stromatolites = some of the best records of early life. Look like lumpy stones, but are actually layers of sticky films secreted by cyanobacterial that trapped particles of sediment

76. The Proterozoic Eon

• 2.5 BYA - 541 MYA

• first multicellular organisms evolve

• no bones, so fossil record is poor

• later in the Ediacaran period, large life forms with some harder parts evolved (including first animal life)

77. The Phanerozoic Eon

• 541 - 0 MYA

• split up into 3 eras, Paleozoic, Mesozoic, Cenozoic --> which are subdivided into multiple periods

• animal life rapidly evolved into a multitude of diverse forms, including dinosaurs

78. The Paleozoic Era

• 541 - 252 MYA

• animal life was restricted to primitive invertebrates living in the oceans

• also had forest that covered the land, full of reptiles, amphibians, and insects

• 1/3 eras in the phanerozoic eon

79. The Cambrian Period

• 541 - 485 MYA

• a period in the Phanerozoic Eon

• marks a dramatic diversification of aquatic life = Cambrian Explosion

• sponges, molluscs, worms, and many arthropods (including trilobites) evolved

• a close relative of vertebrates evolved = Pikaia

80. Pangea

The continents collided together to form a supercontinent

• happened during the Permian period

81. The Permian Period

• 299 - 252 MYA

• Pangea formed

• three major lineages of reptiles evolved

82. The Mesozoic Era

• 252 - 66 MYA

• often referred to as the Age of the Dinosaurs

• dinosaurs evolved during this time and became the dominant form of large terres-trial life

• 2/3 era in the phanerozoic eon

• includes the Triassic, Jurassic, and Cretaceous periods

83. The Cenozoic Era

• 66 - 0 MYA

• Age of the Mammals

• extinction of dinosaurs (except for birds) allowed mammals to evolve larger forms and to fill many of the ecological roles

• grass became abundant

• 3/3 era in the phanerozoic eon

84. The Triassic Period

• 252 - 201 MYA

• life gradually began to recover from the End Permian mass extinction

• first mammals and dinosaurs evolved during the Late Triassic

• first ornithischians, theropods and sauropodomorphs appeared (all small and bipedal)

• Ichthyosaurs, Plesiosaurs, Pterosaurs, and Rhamphorhynchoids evolved

85. Ichthyosaurs

• evolved during the Triassic Period

• name means fish lizard - but they are neither fish nor lizards

• ancestors were terrestrial reptiles (found success by returning to water

• evolved paddle-like front and hind limbs as well as a finned tail

• shark-like dorsal fin

• long snout with conical teeth (piscivorous diet)

• never evolved gills and had to come to the surface for air

86. Plesiosaurs

• Evolved during the late Triassic Period

• are the best ones

• large chest and torso

• broad-paddle shaped limb

• varied tremendously above their shoulders - some had short neck and huge jaws, while other had long necks and small heads

87. Pterosaurs

• Evolved during the Triassic Period

• commonly known as pterodactyls

• first vertebrates to fly

• branched off from the reptilian family tree

• have membranous wings supported by a single extremely elongated finger (this differs from birds and bats)

88. Rhamphorhynchoids

Group of early Pterosaurs

• common in the Late Triassic and throughout the Jurassic

89. The Jurassic Period

• 201 - 145 MYA

• dinosaurs continued to diversify

• peak sauropod diversity

• small theropods were the dominant terrestrial carnivores

• Pterodactyloid group evolved from Rhamphorhynchoids pterosaurs

90. The Early Cretaceous Period

• 146 - 100 MYA

• dinosaurs continued to diversity

• Mosasaurs evolved

91. Pterodactyloids

Rhamphorhynchoids pterosaurs gave rise to this new pterosaur group

• evolved during the Jurassic Period

• differed from Rhamphorhynchoids as they has short tails and had carpels in their wrist

• had large head crest

• were some of the largest animals to ever fly

92. Mosasaurs

• evolved during the early Cretaceous Period

• relatives of modern monitor lizards and snakes

• had tail fins and limbs modified into paddles

• some were very enormous

• adapted for deep-sea big-game hunting

93. The Late Cretaceous

• 100- 65 MYA

• considered the apex of non-avian dinosaur diversity

• many famous dinosaurs evolved

• at the end of the Cretaceous a large meteor collided with the earth which killed off our nonavian dino buds

94. What did Alfred Wegener notice?

1. that the eastern coastline of south Ameri-ca and the western coastline of Africa looked as if they fit together like puzzle pieces

2. fossils of many ancient animals could be found in both South America and Africa (animals not capable of swimming)

3. several geological formations in South America had seemingly identical twins in Africa

95. What did Alfred Wegener suggest based on his observations?

That South America and Africa were once connected and had since drifted apart

• however Wegener could not offer a convincing mechanism for how the land masses could move (later on this mechanism was eventually explained)

96. Crust

The outermost layer of the earth

• consist of ocean basins

• very thin in comparison to other layers

97. Mantle

The layer of the earth below the crust

• very thick

• uppermost part of the mantle is solid and called the lithosphere

• The lower part of the mantle is viscous and called the asthenosphere

98. Lithosphere

The upper portion of the Mantle

• composed of many discrete plates that fit together

• is solid

99. Asthenosphere

The lower part of the Mantle

• is viscous and slow flowing (but not a liquid) due to the intense heat and pressure (like play-doh)

• its shape may be deformed under the uneven weight of the atmosphere

100. Core

Layer beneath the Mantle

• primarily composed of iron and nickel

• subdivided into the Outer and Inner Core