1Uniformitarianism (Lyell)
The theory that natural processes observable today were responsible for events in the past
2How did geology help Darwin establish his theory?
Both development of geological formations and evolution have slow/observable processes that cause large changes over time
3Radioisotopes
- Ustable isotopes with fixed probabilities of decaying into a more stable form
4Half Life
amount of time for 1/2 the atoms in a radioisotopic material to decay
5Radioisometric Dating
- Uses the decay of radioisotopes to determine a precise time range of a geological discovery (e.g. a fossil)
6The Earth and Solar system are ______ years old
4.56 billion
7The vast majority of organisms become fossils. (T or F)
False
Special conditions are requred for fossils to form, so most organisms do not become fossils
8Fossils can reveal the ________ of species.
- behavior (mating, herding, birthing, etc.)
- development
- nutrition
- age of individual
9CT scans revealed that a Hardrosaur crest is used to....
make sound by passing air through it. This reveals the communication and group herding of Hardosaurs.
10Fossils reveal that Trilobites...
Grow steadily (based on their head length and width)
11Carbon isotopic signatures are used to infer the _____ of species.
diet
12The tooth enamel of early hominins has a low ¹³C:¹²C ratio, meaning...
their diet was high in C₃ plants, since such plants are high in carbon-12
13The tooth enamel of more recent hominins shows a high ¹³C:¹²C ratio, meaning
their diet was high in C₄ plants, since such plants are higher in carbon-13
14Lagerstätte
a site with very well-preserved fossils (including soft tissue) from the same time period (e.g. Burgess Shale in Canada)
15Biomarker
a distinct molecule produced only through biological activity
16Okenane
a substance in rocks that reveals the presence of purple sulfur bacteria during time period
17What does the presence of Okenane indicate?
That the ocean had low levels of oxygen and high levels of sulfur 1.64 billion years ago.
18It is indisputable that life existed on Earth _____ years ago
3.5 billion
(stromatolites)
19Stromatolites
- oldest indisputable fossils (~3.5 billion years old)
- layered mineral mats created by microbes
20LUCA
- last universal common ancestor
- hypothetical organism that all life descended from
21How did multicellularity evolve?
Independently to form several lineages
22First fossil of a multicellular organism dates back _____ years.
2.1 billion
23The first multicellular eukaryotic life was _______ from _______ years ago
aquatic algae, 1.6 billion
24The oldest lineage of animals is _____
Ctenophora (comb-jellies)
25Oldest appearance of animals in fossil record is ________
- Porifera (sponges)
- Special cholesterol biomarker dates to 635mya
26Animals with nervous and muscular systems came about _____ years ago
585 million (40 million before Cambrian Period)
27Cambrian Period
541-485 mya
28Ediacaran fauna
-Diverse and unique animal communities in the ocean 570-540 mya
- They don't fit well into the tree of life
- Most specifics are a mystery
29Cambrian explosion
The rapid diversification of multicellular life that took place during the Cambrian period (541 mya)
- food webs emerged
30Chordates
-First appeard 515 mya
31Terrestrial prokaryotes
- first life to colonize land
- 2.6 bya
32Terrestrial eukaryotes
- animals, plants, and fungi
- appeared much later than prokaryotes (<500mya)
33Oldest terrestrial plant fossils resembled
- mosses and liverworts
- 475 mya
34Terresterial ____ appeared ~75 million years after terrestrial plants
fungi
35Large forest ecosystems appeared _____ years ago
375 million
36Invertebrate trackways date to ___
480 mya
37Terrestrial invertebrates are probably relatives of ____
insects and spiders
38Oldest fossil of fully terrestrial animal
- millipede
- from 428 mya
39Oldest vertebrate trackways
- likely made by tetrapod
- 390 mya
40Oldest tetrapod fossils
- 370 mya
41Many familiar forms did not emerge until
~300 mya
42First insects evolved
~400 mya
43Synapsids appeared ____ years ago
320 million
44Indisputable mammals evolved ___ years ago
160 million
45______ quickly diversified after dinosaurs went extinct ____ years ago
Mammals, 65 million
46____, _____, and _____ all emerged around 50 mya
Whales, bats, and primates
47Oldest human fossil dates to about _____ years ago
300,000
48Zicron
- mineral that preserves carbons from billions of years ago
- helps us understand early earth