History of Life Flashcards

Question

Oxugenation + determanistic

Answer 1

Example of thinkning about determinalistic If Decrease in O2 and increase in CO2 = prime for Photosynthesis to evolove Here photosynthesis is lilley = oxygenation of earth might have been inevitible based on evolution of photosynthesis

Answer 2

The end of banded iron Formation = 1.8 BYO At the same time as Eukaryotes show up + complex fossils 100X larger than bacteria show up - Increase in Oxygen = start to get evidence of Eukaryotic fossils (still microfossils but more complex shape and stucture)

Answer 3

Eukaryotes Trace their origins to endosymbiotic relationships among earlier prokaryotes - Have Endosymbiotic with Eukaryotes and microbes Allowed for aerobic metabolism Progentors of Eukaryotes are more closley related to Archea than Prokaryotes

Answer 4

Structuraly complex cells with distict orgenelles

Answer 5

Prokaryotes are important with evolution of mitochondrial --> Spurring diversification of Eukaryotes

Answer 6

Likley only occured once Have Eukaryotic protists that lack mitochondria --> have evidence of horizontal gene transfer = they evoloved from ancestors with mitochondria

Answer 7

Fossil dates for Eukarya match well with molecular evolution estimates of mitochondria acquisition

Answer 8

Multicelularity first shows up in algea 1.6 BYO Doesn't occur in animal like forms for another billion years - NOT in our ancestors for a while

Answer 9

Hadean --> Unstable hot earth + bombarded Archea -- life evolved but less evidence because no rocks from archean Proterozoic --> microbial + interaction of living world and atmopshere paved way for mitochondria evolution

Answer 10

Means visibile life -- see big things --> Dawn of multicell animals Orginally this eon coincded with dawn of metazoan diversity (multicellular animals) BUT orginals stretch back into proteozoic - Not just multi animals show up on own 541 MYO --> roots of multi cell streatch to protozoic

Answer 11

Earliest fossil evidence of animal life forms include sponges 600 MYO - See same deposits that have fossils that are similar to internal sticture of sponge (not whole sponge just have small peices) Motile animals date back to 585 MYO BUT mostly trace fossils of tunnels and tracks - Have evidence of things movingar around

Answer 12

Trace fossils -- not body of organisms but have fossils that detects the activity of organisms (trails + burrowing in the sea floor) See animals doing things but don't know what they are but know things are around ocean floor 585 MYO

Answer 13

Starting 575 MYO -- have first ecological assemblages of the large organisms --> Ediacaran Fauana - Evidence of Muti cell animals NOW = see animal life in complex ecological communities - Seen in Australia + South Africa BUT now have evidence from 25 Sites across world --> ALL have similar groups of organims

Answer 14

Some organsims = 1 mete long OR some are a few cm SHOWS it is NOT just small things - Almost all of the sudden have big things + big shift in composition of biodiversity (Microbes --> Multi cell)

Answer 15

Most fossils found are very weird -- weird because we can't connect them to types of animal diverity we have today Weird we have today fiots into our own classification BUT These weird organisms have such different body plans that they might not be in animal phyla or in a classification that doesn't exist today

Answer 16

Major Questions surrounding this time - what if any realtionships do these organims have to modern aniamls - Basic body plans are very different from current phyla - Was this a false start? --> they don't seem like they are related to us

Answer 17

Proposal that many Ediacaran forms are so fundementally different that they comprise an extict kingdom outside of Animalia altogether - Maybe these things are not animals at all -- differemnt multi cell heretotrophs that are not animals Have branch of phylogeny for Vendobionata branch -- before common ancestor of animals today - Found different groups of animals -- if they kept evoloving things would be different than they are today

Answer 18

Answer: ALL are equally related -- Need to look at internal nodes - They all share the same common ancestor with humans at the same time = none are more closely related to humans

Answer 19

Gives Identical phylogeny

Answer 20

People say that the Fish and Seaslon have more nodes between them and humans BUT this is just set up this way (just a function of the species we chose to include in the cladogram) IF we change organisms = we get a different answer - Arbitrary number doesn't tell you anything about being more related to humans

Answer 21

Form a clade by sharing a common ancestor

Answer 22

First large multi cellular organisms - In end of Protorozoic

Answer 23

Even if Edicaran Fauana arn't related to us some of our metazoan ancestors must have been around - Know ancestors during time were around but they are not seen in fossils

Answer 24

Do see living things in high abundance

Answer 25

Perhaps the issue is in Tophanomic bias - Maybe in different places or maybe taphanomic bias ***Maybe our ancestors don't fossilize well

Answer 26

Processes related to the fate of organisms remains - bias in porcess that leads to fossilization - Fossil record is not compelete --> cam't actuallyf ind organaism -- bias in what are fossils or not

Answer 27

Permian = Fossils are weird compared to modern in that the trophic structure is different (Have more autotrophs that heterotrophs = higher prey than predator BUT in the fossils in the permian it is flipped - have tons or predator and few prey) - Food web might gave been the same as ours it is just that there is bias that we get fossils of predators and not herbivores) Result: Unusual patterns wherte fossils are biased

Answer 28

Some glimer of hope of organisms related to modern phyla in fossils but not what we recognize as adults --> The fossils seem similar to embryos + microfossils of embryos - Shows embryogenesis similar to modern phyla - Perhaps ancestors were thing - Some connections to bilaterans maybe fossilized embryos from Doushantuo formation

Answer 29

Start of the Phanarazoic Represents period were modern animal phyla appear Multi cell show up very abruptly See diverse large animals but almost all modern phyla are present in fossils - By middle of the cambrian all of our major phyla are present - Rapid doversification of animal morphology = Cambrain Explosion

Answer 30

Connections to modern phyla are tenous in the Ediacaram BUT by the middle of the Cambrian all of our major phyla are present

Answer 31

Burgess shale -- first thoroughly studied aseemblage of early animal life - See laminated sedimentary rock --> have small fossils + animal fossils -- earliest multi cell animal fossils - See fine detail + in high abundance - Struck by tremendous diveristy - Many very bizzare animals BUT we see the foundations of modern phyla Example of a Lagerstatte

Answer 32

A particularly rich fossil deposit including organisms that don't typically fossilize well - Have lots of organisms including things that have lots of taphonomic bias (like fossils of warms) Good because of the type of sediment with degree of well preserved organisms

Answer 33

See foundations of modern phyla --> Clearly arthropods -- can draw direct connection to animals alive today See: 1. Clear Arthrodpod relatives 2. Joint Appendages 3. Exoskeltons segments 4. Segmentaled body plans (All things Artrhopods have today)

Answer 34

Phylum level diveristy is based on diversity of basic body plans (Bauplane) - Blueprint for how make organisms = what decides what phyla - All fundemental animal diversity = based on organisms having different body structures driven by development ALL body plans = in place in the cambrien

Answer 35

If all phyla are present in the cambrien = all basic animal body plans are present - All of the diversity in fundamental body stricture that we see today dates back to the cambiren

Answer 36

Why do animals have the set of Bodyplans that they do? Is there something optimal about them that natural selection was going to inevitable reach OR is this due to historal accicent - Why do we have the set of phyla that we do (essntially fixed) --> was anything inevitable or are phyla today result of happenstance

Answer 37

The study of how developmental processes (ultimately controlled by gene expression) evolve - resulting in new morphological features - How organisms develop + how developmental processes evolve + hows does variation arise - Use underlying genes of developmental paths

Answer 38

To Answer = could look at evolutional Devlopmental Biology Answer: Understanding coming out of Evo Devo = there is a shared tool kit of almost all animals that allow different body plans to develope - Diversity in body plans = based on set of key homogous genes (orthopgies) that control process

Answer 39

Fly has set of HOX genes + have set pf Mice HOX genes --> Pattern across fly = similar to pattern in mammals - Have different morphologies from the same tool kit - Genes occur along the chromsome in the same order

Answer 40

Evolution of base level tool kit Constraints for ways for genes to be expressed for body plan development = constrains in limited number of phylogeny - Limited way to produce functional body plans

Answer 41

Chordates -- Body plan that certainly dates back to Cambrien explosion - Clear they are early ancestors Fossil = dorsal groove + similar bilateral plan -- similar to modern lancelet

Answer 42

Chengjang -- more recently discovered but older than Buregess Haikoichtyhas -- oldest known vertabrete - See gill nodes + eyes on head + fins more developed

Answer 43

Why did it take so long for animals to get bigger --> partly took kit -- get organisms to develope in multi cell ways that have funcational body plans takes long AND -- leading hypothesis = Simply could not have happened until oxygen reached critacal threshold - Waited for atmosphere to get even more modern - Oxugen increased in cambrien = can reach critical threshold to allow developemy of larger organisms (support comlex fast moving animals)

Answer 44

Compared to the Archean and proterozoic - the pace of evolution seems much faster during the phanerozoic (at least from a human persepctive) - From our perspective things pick up rapidly

Answer 45

During Cambrien = earth had lots of climate change (warm --> Cold swings) - Ediacaran = might exist during a breif warm period and our ancestors might benefit from being able to survive ocelations of warm --> cold

Answer 46

Aquatic life continues to flourish

Answer 47

Oceans = still dominated by invertabretes (arthrpods + Molluscs) - Oceans = filled with animal life - Some animals get larger (7 feet long) Vertabrets are still confied to jawless fish - Have vertabretes BUT are little jawless fishlike creatures (Still have today) - Jawless = helpless

Answer 48

Vertabretes have been around since the Cambrien BUT oceans were dominated by Invertabreted into the Oridivician period - Still have these jawless vertabretes today but they are not the dominant form of vertabretes Example - Hagfish

Answer 49

Fish begin to diversify -- most species are heavily armnored but still jawless - Start seeing diversifcation of vertabretes AND - Jaws evolve from gill patches in another armoered taxons

Answer 50

Jaws evoloved from gill patches in Placoderns (Armored taxon) Done in the end of Sullarian

Answer 51

Most fish = jawless BUT do better because they evoloved armor (Ostracoderms) -- survive more by being armored BUT are still Jawless (limited in what they can do)

Answer 52

Critical to reshaping biodiversity --> process that was critical is the evolution of jaws Gills arch moves to shovel things to mouth = evoloves to power of jaws --> change selection of ecological oppertunities for relatives Change in fossil record leading to new period of Deveonian

Answer 53

Age of fishes -- Jawed armored fishes + plancoderms = take over = means our ancestors are doing well - Transition is NOT accompanied by a mass exitiction event (have major reordering of biodiverity without event)

Answer 54

Likley to ancestor to all modern Gnathostomes (Jawed vertabretes)

Answer 55

Allowed vertebrates to quickly dominant the seas Diveristy = owed to the evolution of powered Jaws Evolution of innovation = allowed ancestors to outcompelte Jawless + invertabretes - Take over seas + diversify early - See pattern of one organsim outcompeting others as soon as jaws show up

Answer 56

Rapid diversification of form continued with bony fish splitting into two major lineages early in the devonian - Split is important because we are lobe fish Bony Fish --> Actinoptergian (finned fish) + Sarcoptergians (lobe fish) - We are lobe fish

Answer 57

Split bony vs. Cartaligounous fish THEN have another split in lineages Cartligenous fish split --> Sharks + Rays + Spiny shark) ***Fish Split early in the devonian where we can trace ancestors of sharks and rays vs. diveristy of bony fish

Answer 58

Humans are in the same clade as lobe fish - Clade includes other vertabretes with bones (IN the clase that had split from bony fish) - All individuals with bines in limbs = dates to early devonian Sets stage for vertabretes moving towards land

Answer 59

The shift form aquatic love finned fish to terestial tetrapod might seem like a huge leap BUT the fossils clearly show the transition from lobed fin skeletons to tetrapod limbs and the development of Pecteral and pelvic Girdles - Series of Transitional fossils that are complete to say when first tetrapods evoloved - Once found the right geologic time and setting (freshwater) --> see these organsims of Jawed tertopods = lead to ancestors on land

Answer 60

Lobe fish = Have joints appendages at the based on limbs that allow for difference used of appendegaes Differnces in Lobe fish = allows them to go to land

Answer 61

First have body structure of tetrapods then support limbs = smooth transition to land - Well documented

Answer 62

Transitional fossils form such a smooth series of limb form that it is hard to say when the first tetrpod exists

Answer 63

Tetrapods evolved as Ambush predators in shallow freshwater environments - Began taking advantages of terrestrial resources (take advantage of arthrpods)

Answer 64

Arthropods had been on land since the Silurian

Answer 65

Vertabretes were NOT the first on land -- arthrpods were the first on land - Tetropods = not too far after Arthropods Aquatic maybe went to land to takes advantage of Arthrpods

Answer 66

Early transitional forms from lobe fish and tetropods = divrse in the number of digits - Have the same Humuras + Radius + Urna THEN the earliest joint = existent but number of digits is very variable BUT now = ancestral stat in existing = 5 --> basic body plan for all vertebrates alive today

Answer 67

5 fingers = could show constraint on body parts --> more developmental stability through time - do we have a limitations on ways we can evolove? When had no wrist bones = lots of digits BUT tetrpods that want to use = have 5 or evolove from ancestor with 5 - Don't see starting from 5 and increasing - Otehr groups of tetrpods have basic body plans of 5 digits (earliest dinasour had 5) -- don't get woth more Even though it is sueful to have extra digits it hasn't happened

Answer 68

Example - panda has an extra thumb --> used to grasp bamboo = it is useful BUT if you look at skeloton it is not a digit un developmental way -- bone is just the wrist elongated

Answer 69

Hands with extra digits --> happens within indiviauls BUT not broad because way it happens in development - Humans can have fingers in development (it is a mistake in development) -- split development pattern and grow futher in hand It is a developmental mistake NOT a new finger

Answer 70

Interpretation by is it optimal or are we constrained Answer: Maybe in the devonian we could have changed BUT we didn't -- now we are past the point of no return = can't go back and revise development from begining

Answer 71

Have rapid diversification of Jawed vertabretes including tertrapods --> had an ecological take over The tetrapods are in habiatats to use limbs and do so well = have chnage in devonian

Answer 72

Vertabretes move onto land in the end of the devonian and begin divergive into major tetrpod groups during the Carbonigerous period

Answer 73

Our tetrpod ancestors emerged during rapid vertebrate diversification of the devonian

Answer 74

Plants beat us out of the aquatic envirnment (Moved to land first)

Answer 75

Vertabretes begin diverging into major tetropod groups - Have ancestors to modern amphibians + Amniotes - Terestrial life included gigantic arthropods THEN have split between Diapsid Amniotes (reptiles and brids) and Synapsid Amniotes (Pelycosaurs and us) Warm with Abundence of Swamp like habitats

Answer 76

Carboniferous period --> Had big plants that now turn into coal

Answer 77

Have explosion of biomass on land with Arthrpods dominating

Answer 78

Ancestors diverged early on land -- Split between Amphibians and Amniotes THEN Aminiotes start to diversify As SOON as you have amniotes --> have split into diaspid reptiles + Synapspid reptiles - We evoloved from Synapsid Reptiles Ancestors = mostly small lizard like amphibians that are more mammal like that led to us

Answer 79

Developed reptiles from Aquatic by having eggs that can deal without water

Answer 80

Have swap and wetland habitats occupied by organisms + big arthrpods (ancetsors were also big) Ancestors = mostly small lizard like amphibians that are more mammal like that led to us

Answer 81

Get period with climate change - Shift in climate + break in pangea (change ocean current = change weather) Get collapse of swamp ecosystem In direer habiats the Synapsid reptiles (mammal side) thrive and diverisfy --> Our Ancestor get footing because synapsid reptiles do well) until volcanic acitivity bin siberia ruined things

Answer 82

Leads to more diverse habiatats and eventually large + diverse + thriving terestial ecosystems

Answer 83

The synapsides were the dominant terestrial vertabretes during the permian

Answer 84

Crashes in the eprmian Go from mammal like reptiles --> Dinasours --> Mamals like us

Answer 85

Earliest Mamaliaforms in Triassic within the Therapsid clade survived the Permian Extiction

Answer 86

Have permian (Have dinasours) THEN Biodiveristy rebounds Earliest mamamles in middle of triassice (things wee call mammals show up in Triassic) - Might technically be outside of clade of mammals we have today -- different group of mammals but have traits we use to destiguish mammals THEN the clade constaining all existing mammals started diverging (Split Monotremees/Marsupials and Therians) - Recent common ancestor of all mammal today (last common ancestor of us and Acindia) - Split in Modern mammals dates to Dinasours THEN Have split between Marsupials and Placentals - Diversity of mammals occuring in background of dinasours - Split between two major clades of exicting live bearing mammals happens in Mid-jurassic THEN the have divergbnce in Marcupials or Placental/Eutherins through the Cretacous - Through Cretacoues = Mammals hang on in dinasour dominated ecosystems (mostly small but some ecological expansion and evolution of size) - Have existing predatoring mamamls that we would diverge in shape Important = Ancestors eveoloving are NOT as succesful as dinasours

Answer 87

Mammals + Dinasours on earth for same amount of time

History of Life Flashcards

(111 cards)