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Biol 321 > topic 4-1 > Flashcards

topic 4-1 Flashcards

1
Q

what eon is most geological timeline within? what isnt included

A

Phanerozoic

pre cambrian not included - it is its own eon and era

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2
Q

what are the four eras oldest to newest

A

pre cambrian, paleozoic, mesozoic, cenozoic

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3
Q

what are the three periods/epochs in the pre cambrian era ((oldest to newest)

A

hadean (4600 mya- 3800), archean (3800 mya - 2500), Proterozoic (2500 mya - 540 mya)

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4
Q

what periods are included in the paleozoic era oldest to newest (540 mya - 250 mya)

A

Cambrian, ordovician, silurian, devonian, carboniferous (missippian, pennsylvanian), permian

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5
Q

periods in mesozoic oldest to newest (250 mya- 65 mya)

A

triassic, jurassic cretaceous

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6
Q

periods of cenozoic oldest to newest

A

paleogene (65 mya-23 mya), neogene (23- 1.5 mya), Quaternary (1.5 mya - now)

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7
Q

epochs in the paleogene (cenozoic) oldest to newest (65 mya to 23)

A

paleocene, eocene, oligocene

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8
Q

epochs in the neoogene (cenozoic) oldest to newest (23 mya to 1.5 mya)

A

miocene, pliocene

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9
Q

epochs in the quaternary (cenozoic) oldest to newest (1.5 mya to present)

A

pleistocene, holocene `

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10
Q

what is needed for radiometric dating?

A

• Absolute ages
○ Based mostly on radioactive decay
○ Need unstable elements with half-lives of appropriate length
○ Only igneous rocks can be dated; therefore, fossil bearing sedimentary rocks must be bracketed between younger and older igneous rock
○ Method not available until mid 20th century
○ Exs. Carbon 14, uranium 235

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11
Q

what can radiometric dating be used to calculate? how old are meteorites? oldest?

A

• Can use to calculate the age of earth and the solar system
○ Dating of meteorites
§ Most meteorites are 4.5 or slightly more byo
§ The earth and other planets must be the same age
□ A few meteorites came from other planets and are a bit younger

The oldest rocks on earth are from northern Canada
+Nuvvuagittuq Greenstone Belt, exposed on the Eastern shore
Of Hudson Bay, Northern Quebec
*Approx. 4.4 billion years Old

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12
Q

oldest fossil of living things?

A

○ The oldest fossils of living things are approx. 3.8 byo

§ Stromatolites from shark bay, western australia

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13
Q

three biases in the fossil record. describe them.

A

• Geographic bias
○ Majority of compression and impression fossils come from marine sediments, lake beds, and floodplains
○ Terrestrial environments, especially tropical ones, are poorly
represented
• Taxonomic bias
○ Fossil record is dominated by marine species possessing shells
○ approx-95% of all fossil animals are marine invertebrates
•
• Temporal bias
○ Older rocks are much rarer than newer rocks

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14
Q

describe contiental drift. look at example in notes

A
  • Theory proposed by German geophysicist and meteorologist Alfred Lothar Wegener in 1912
    • All continents were connected as one large land mass (he named it Pangea) about 200 mya; continents are slowly drifting around the earth
    • Evidence: matching coastlines, similarity of fossils - south america and africa
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15
Q

when were plate tectonics discovered? describe it

A 
• Discovered in the 1950s 
	• Earth's crust divided into 
	plates 
	• Plates move relative to 
	one another - tectonic activity
	• Plate movements cause 
	continents to move also 
	North America is moving 
	west at about 2cm/year 
	• Europe is moving 
	northeast at about 
	3cm/year 
	• Most ocean basins are not 
	older than about 200 
	million years (Jurassic 
Period)
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16
Q

geoloical time summary/ conclusions

A

Geological Time: Conclusions
Cosmic distances and cosmic time are known
independently of the dating of earth events.
The solar system including earth is about 4.5 billion years
old, estimated from ages of meteorites and moon rocks.
The surface of the earth is composed of plates that
o
move. The ocean basins are relatively young, nowhere
older than Jurassic.
Plate movement rates are measured directly by satellite-
born laser devices, confirming the radiometric ages of
the rocks forming the ocean basins.
The 4.5 billion-year old age of the earth, the
approximate 13 billion-year old age of the universe, and
the ages of many, many earth events are scientific facts.

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17
Q

changes with lineages in fossil records examples

A

• Changes within lineages
○ Foraminiferans, trilobites, sticklebacks,, and suckers
• Origin of higher taxa
○ Tetrapods, birds, mammals, whales, humans

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18
Q

describe the change in lineage reharding foraminiferan shells

A

• Study by kucera and malmgren 1998
○ Increasingly cone shaped shells over a period of approx 3 million years
○ Gradual evolution (likely anagenesis)
○ Note first 2.5 my of stasis - no change

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19
Q

describe the changes within trilobite lineages

A

• they Can be documented in continuous, fosiliferous sections of sedimentary rock
• e.g. trilobites - study by sheldon, 1987
Various species in different genera changing gradually in the
same feature: number of ribs on the rear dorsal part of the
exoskeleton over about three million years

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20
Q

describe changes in lineage with sticklebacks

A
  • Samples 5-10,000 years apart in annulally layered lake beds
    • Several features of the sticklebacks changed gradually but not always In the same direction
    • One feature might increase in number of parts while another might decrease
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21
Q

describe changes in stickleback lineage

A
  • Study of fossil sticklebacks (Gasterosteus) by M. Bell 1985
    • Samples 5-10,000 years apart in annulally layered lake beds
    • Several features of the sticklebacks changed gradually but not always In the same direction
    • One feature might increase in number of parts while another might decrease
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22
Q

Change within lineage: Amyzon sucker

A

• Studies of amyzon by mark Wilson and Doug Barton 1996, Barton and wilson 1999
○ Eocene (50 my old) suckers from B.C.
○ Preserved in annual layers called varves
- changes in vertebrae over 600 years
changes in fin rays over 8,000 years
exhibit in UofA
slow drop in dorsal vertebrae, more varying in dorsal fin rays
fossils came from a very narrow window of time

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23
Q

origin of terapods from lobe finned fish ex and features. look at specimens found in quebec

A

e.g., Eusthenopteron
- a rhipidistian
- Devonian
• Internal nostrils
• Lungs and gills
• Limbs with bony
axis
• Labyrinthodont
teeth
• Skull with
tetrapod pattern of bones

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24
Q

what discovery helped us better understand the origin of tetrapods? who discovered and where

A 
a discovery in 2004 of a 
	Late Devonian tetrapod-like fish 
		○ By Dr. Neil Shubin of the University 
	of Chicago & his colleagues 
		○ From Ellesmere Island in the 
	Canadian Arctic 
		○ Provides important insights into the transition between sarcopterygians and tetrapods 
		○ Tiktaalik roseae
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25
describe tiktaalik and its features. how many specimens found
○ Tiktaalik roseae ○ Has a mix of fish and amphibian traits ○ Looked like a cross between the primative fish and amphibians ○ Lived amongst the first tetrapods ○ Tiktaalik - shallow water fish ○ Transitional form from late devonian ○ Termed "fishapod" as it intermediates between fish (eusthenopteron) and early tetrapods (acanthostega and ichthyostega) ○ More than 10 specimens, 3-9 feet ○ Eyes located dorsally ○ Crocodile-like flattened head with sharp teeth ○ Well developed lungs
26
describe skeletal modifications of tiktaalik
``` Pectoral girdle z Like a lobe finned fish but also a distinct shoulder, elbow, & wrist Fish like fins (no toes) Neck could move independent Of body (unlike other fish) ```
27
tik taalik rib cage and pelvic girdle features
• Rib cage ○ Well developed and tetrapod llike ○ Suggests benthic (shallow H2O) habit: could move on land for short periods • Pelvic girdle ○ Primitive features: no ischium; no attachment for sacral rib ○ Advanced features: enlarged; paired with broad iliac processes, flat & elongate pubes (bone)
28
tiktaalik summary
• Closed 10 my gap between sacropteryian ancestors and their tetrapod descendants Fish-like: gills, scales/fin rays, caudal fin Fishapod-like: limb bones & joints Tetrapod-like: ribs, neck, lungs
29
late devonian rhispidistians and early tetrapods from oldest to most recent
pandrichthyd and eusthenopteron, tiktaalik, ichthyostega and acanthostega and coelacanth
30
first significant origin of bird specimen? decribe
Archaeopteryx lithographica, Jurassic of Germany • Toothed, long tailed, claw-winged bird; skeleton discovered 1860 dim • 10 specimens known • Possibly more than one species or genus • Discovered in germany
31
first archaeopteryx specimen?
``` • The first fossil of Archaeopteryx was a single feather, found in 1860. ○ This feather was not only exceptionally preserved but showed the asymmetric form that is characteristic of flight feathers. - probably could fly ```
32
• The london specimen archaeopteryx
• This specimen found in 1861, called "The London Specimen" was significant in that it established the type of bird from which the single feather found the previous year was derived. • The London Specimen now resides in the Natural History Museum in London, U.K.
33
The berlin specimen archaeopteryx
``` • By far the most famous and best-preserved specimen of Archaeopteryx is the Berlin specimen discovered in 1877 (curated in the Humboldt University Museum of Natural History in Berlin) • This specimen shows most of the significant features that are considered evidence of a dinosaur-bird connection. (even teeth) ```
34
recent archaeoptryx fossil
Specimens of Archaeopteryx are still being discovered Mayr et al. (2006): the 10th specimen, one of the best found
35
what did birds originate from? describe them
• From theropod dinosaurs ○ Feathered dinosaurs: early cretaceous of china ○ Feathers are not only a bird characteristics - feathers originally evolved for insulation, not flight ○ Many kinds discovered ○ Different types of feathers ○ Feathers on various parts of body
36
describe the earliest feathers
The earliest feathers were probably keratinaceous bristles - protofeathers Sinosauroteryx primus — a basal coelurosaur from China With traces Of filamentous protofeathe
37
• Derived features in modern birds compared | to Archaeopteryx
1. No teeth 2. Expanded braincase with fusion of many elements 3. Fusion & reduction of three digits of forelimb 4. Fusion of pelvic bones & several vertebrae into a single synsacrum 5. Fewer caudal vertebrae with fusion 6. Sternum enlarged & keeled 7. Horizontal processes to strengthen rib cage Birds have a common ancestry with reptiles
38
• similar features in theropods compared | to Archaeopteryx
long hand bones, leg structure and claw shape
39
what did mammals arise from?
• From synapsids ○ Pelycosaurs and therapsids • Synapsid clade • The name "mammal-like" reptile is misleading • synapsids and reptiles - two distinct groups of amniotes
40
describe pelycosaur
§ Pennsylvanian/late carboniferous - permian § e.g. dimetrodon § Gave rise to therapsids
41
describe therapsids
§ Permian § e.g. biarmosuchus Gave rise to mammals
42
compare synapsid and terapsid skulls
synasids had large jaw muscles, multiple bones in lower jaw, and single cusped teeth synapsids in the order therapsida had large canine teeth, large maxilla bones, and long faces
43
compare fish jaws to mammals (look at diagram)
* Mammals have a squamosal dentary articulation - 3 middle ear bones instead * Check flashcards from zoology for better understanding of this * One clue of when mammals arrived - 1st synapsid without quadrate articular articulations
44
evolution of middle ear bones from jaw joint bones ( look at pic)
ok
45
describe cynodonts
``` Cynodont - advanced group of synapsids that gives rise to mammals pecialized therapsids • Late permian - late triassic • Primitive: ○ Procynosuchus Typical: thrinaxodon ```
46
when did middle ear bones become separated from the jaw
two separate lineages - monotremes and eutherians
47
describe primitive cynodont
○ Procynosuchus | - the side of the brain case was verticle and the large temporal fenestra was lateral to it
48
describe typical cynodont
the cynodont dentary (major jaw done) became enlarged, and the cheek teeth had multiple cusps • First time we see multicusped teeth
49
compare Advanced cynodont probainognathus to early mammal
``` In advanced cynodonts. complex cusp patterns enhanced chewing and the dentary formed an articulation with the squamosal. ``` ``` Morganucodon was almost a mammal, with typical mammalian teeth and a lower jaw composed almost entirely of the dentary. The jaw had a double articulation with the skull. - dentary squamosal and articular quadrate articular - two sets found in these ```
50
describe probainognathus jenseni
``` • Middle & Upper Triassic (247- 200 mya) of South America • A carnivorous synapsid; about size of a house cat • First indication of specialized teeth ○ Upper jaw § Squamosal alongside quadrate ○ Lower jaw Dentary alongside articular ```
51
describe near mammals
``` • Late triassic to early jurassic • e.g. morganucodon ○ Almost a model ○ Three middle ear ossicles yet to be found ○ Shrew sized insectivore ○ Double jaw joint § Squamosal dentary in front Quadrate articular in back ```
52
when did true mammals come about? what kinds
* Late jurassic to present day | * Monotremes, triconodonts, multituberculates, marisupials, eutherians
53
what fall under cetaceans
* Late jurassic to present day | * Monotremes, triconodonts, multituberculates, marisupials, eutherians
54
• Systematic position of cetacea traditional view | •
``` Domain Eukarya Kingdom Animalia Phylum Chordata Subphylum Vertebrata Class Mammalia Order Cetacea Whales & Dolphins ```
55
current cetacean systemic position proposal
``` Domain Eukarya Kingdom Animalia Phylum Chordata Subphylum Vertebrata Class Mammalia Order Artiodactyla/Cetartiodactyla Suborder Whippomorpha Whales, Dolphins, Porpoises, & Hippos Infraorder Cetacea Whales, Dolphins, Porpoises ```
56
why should we study the origin of cetaceans
• Captures public imagination - reason for research (more below) • One of the greatest stories of adaptation and conversion • Often ridiculed in anti-evolution literature Ie. "they want us to believe that a cow can become a whale"
57
new evidence on cetacean phylogeny
• New evidence from ○ Molecular phylogeny ○ Fossil discoveries • Formerly thought to be close relatives of artiodactyla New molecular evidence places them as the sister group to a particular group of artiodactyls: the hippos
58
first fossils of cetaceans
• Cetartiodactyla • First fossils from the early Eocene of Pakistan and nearby areas • Oldest fossils come from freshwater deposits, retained ability to walk location: remnants of the tethys sea • 50 mya - world was covered by panthalassic ocean Located near moving india and africa in the south
59
look at pic of the fossils
ok
60
describe cetaacean swimming style
paper in 2016 proposed this went from drag faced to lift based Quadrupedal paddling/ bottom walking (alternate strokes of four limbs) to Pelvic paddling (alternate or simultaneous strokes of enlarged hindlimbs only) to Pelvic undulation (?Ambulocetus) (wave like motions of vert. column) to Caudal undulation (wave-like motions of lumber and caudal portions of vert. column) to Caudal oscillation (whole body in the same phase)
61
whale evolution in hearing
2004 paper earing evolution - could not ? keep their ear canal open bc theyre in water constantly more compact bones like other aquatic vertebrates large mandibular foramen for mandibular fat pad = used to transmit sound
62
foot and ankle connections in cetaceans
ankle, foot and toes of basilosaurus isis egypt • Collected by dr gngerich of U of michigan Foot and ankle connections 1990 ankle joint evolved from single pully to double pully astragalus (ankle joint) ised tp group them
63
darwin on origin of humans
"light will be thrown on the origin of man and his history". from On the Origins of Species, 1859 o "... the weighty arguments derived from the nature of the affinities which connect together whole groups of organisms- their geographical distribution in past and present times, and their geological succession. The homological structure, embryological development, and rudimentary organs of a species remain to be considered, whether it be man or any other animal, to which our attention may be directed; but these great classes of facts afford, as it appears to me, ample and conclusive evidence infavour ofthe principle of gradual evolution. The strong support derived from the other arguments should, however, always be kept before the mind." from The Descent of Man, 1871
64
origin of humans fossil record
fossil record of hominins (sister group to chimps) shows gradual or stepwise change in numerous features, including body size and brain size
65
lineages of homonin taxa?
lots, know that lucy (australopithecus afarensis) had bipedal trackways and was first to show bipedalism
66
look at homonid skulls diagram. what stands out
* B is lucy - more similar to chimps than humans, but does show bipedal - why shes in hominids * Homo habilus - spinal cord opening on skull is starting to move forward and downward - shift towards upward posture * Increase in cranial capavity from h. erectus
67
origin of humans - changes
``` Homo erectus to H. neanderthalensis to H. sapiens -Gradual less jaw projection -Increase in cranial capacity H. erectus: 1175 cc H. neanderthalensis: up to 1600 cc H. sapiens sapiens: 1400 cc Bain size : body size ratio higher in H. sapiens ```
68
neanderthal vs homo sapiens skull
* In homo sapiens - body size and brain size is better in homo sapiens than in neaderthalensis, but neanderthals have a bigger brain * Neanderthal more primative: brow ridge, brain to body size (lower ratio than humans)
69
neoteny in humans
• Retain juvenile form into adulthood - human adults are big babies if looking at head size and shape
70
origin of humans summary
Hominin evolution Mosaic evolution: different features evolved at different rates Brain size increased throughout the evolutionary history but not at a constant rate Progressive changes associated with teeth, facial features, pelvis, hands, and feet Evidence of neoteny in head size and shape Evolution Of bipedalism may be related to use Of forearms to carry food back to social unit; eventually further involved in use Of tools

Biol 321 (22 decks)

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