Evolution Exam 1

Chapters 1 thru 5

Evolution (old definition)

Heritable changes in a population over time; Darwin’s phrase: “Descent with modification”

Fixity vs. Transformism

Species never change vs. species evolve over time

Aristotle’s Scale of Nature

Ladder of life; humans are at the top below God and everything else is below humans in ordered creation

Plato’s Essentialism

Had a similar idea on Creationism but argued creation wasn’t ordered

Linnaeus (swedish)

Believed in creationism; but invented the classification system (Kingdom, Phylum, Class, Order, Family, Genus, Species)

Buffon (french)

Against Creationism; said the earth is old because iron takes long to cool; wrong reasoning but right direction; accused of heresy

Cuvier (french)

Believed in creationism despite much of his research going against it; studied extinction and the bones of reptiles

Lamarck (french)

Believed in Transformism but that it was linear and didn’t branch off in terms of inheriting acquired traits (giraffe neck idea was wrong)

Lyell (British)

Geologist; did not believe in creationism; uniformitarianism + continuous change

Darwin (British)

HMS Beagle travel at 22; Idea of Finches (beak shape determines food type, that there must be a common ancestor between the finches and that they adapt) Concluded after reading Malthus that too many offspring produce lead to survival traits getting passed down

Natural Selection (Darwin)

= Variation + Heredity + Morality

Wallace (British)

Developed the theory of Natural Selection and Evolution like Darwin

Mendel (Austrian Monk)

Best known for his pea plant experiment; Coined the terms dominant and recessive; published his idea in 1866 though it was ignored until about 1900; combined with Darwin’s evolution theory

Evolution (new definition)

The change in allele frequency through time in a population

The Big Bang Theory

Roughly 14 billion years ago; dispersed about 77% of hydrogen and 23% helium; Universe is flat but expanison in three dimensions (x,y,z)

Dark Energy

Majority of the universe

Dark Matter

Tiny blackholes with large masses formed during the Big Bang

Evidence for Big Bang

Lighter elements formed first and most abundant then heavier elements, backgroud radiation, red shift (stuff moving away), galaxy clusters

The Milky Way

10 billion years old; from the observations of white dwarfs; rotates once every 250 million years

Solar system

Suns, planets, moons (combination of gas and cold dust); formation from gravitational pull and matter (dust)

Heavier elements

Form in supernovas or possible neutron star collisions

Lighter Elements

Form in stars

Earth

Composed of Iron and Nickel in the core and Silicates in the crust and mantle;

Moon

Formed after Earth; small object collided into earth, once a disk of debris around Earth

Early Earth Atmosphere

Heated up by radioactive decay (planet gets hotter and hydrogen, Water, Nitrogen gases are produced; Early earth was good for life; oceans formed by zircon crystals (4.5 bya)

Temperature on Early Earth

Warmer on Earth despite small sun; cause was greenhouse gases (much CO2 in the atmosphere)

Snowball Earth

All coeans on Earth were frozen 10 bya; No life (only in hot springs and volcanic areas) until acid rain (carbonic acid) melted ice and earth goes back to normal

Rock types

sedimentary (fossils found here) igneous, metamorphic

Fossil Dating on rocks

Can be determined by using the top line of igneous rock and the line below the fossil

Tectonic Plates evidence

Wegener noticed continents fit like puzzle and matching fossils across continents; Glomar challenege in 1960s, drilled ocean floor — young ocean floor (less than 100 million years) vs old continents (billions of years old); magnetic anomalies (iron aligns to north and south poles, poles flip about every 1 million years; Light rocks on continents heavy rock in the ocean; earthquakes map right onto plate boundaries

Oceanic Crust

Heavy; 3.2 density; gabbro; sinks lower into earths mantle

Continental Crust

Light; 2.6 (density); granite; forms dry land and mountains

Divergent Boundaries

Tectonic plates moving apart; magma rises from mantle and forms new crust

Convergent Boundaries

tectonic plates colliding together; heavy rock under light rock, rock melts —volcanoes

Transform Boundaries

tectonic plates horizontally pass each other, jagged edges lock together, release is also a release of built up pressure —- earthquake

Hotspots

stationary magma under moving plates, island chains, oldest island = farthest away

Hawaii chain bend

50 mya; caused by India hitting Asia, changed Pacific plate direction

India

Moves fast (10 cm vs normal 1-3 cm a yr) rammed Asia = made Himalayas and Everest

Pangaea

Broke up 200 -150 mya and split into Laurasia (north) and Gondwana (south); split by Tethys sea

Origin of Life

Minimal evidence; Not spontaneous generation; 4.5-4.0 bya; Crick thought life could have arrived from some place else but still 4.5 billion yeas ago

Metabolism first

argues enzymes and proteins are first but doesn’t account for that they cannot self replicate

Genetics first

argues that DNA/RNA came first but doesn’t account for them lacking catalytic ability

Why Carbon and not Silicon

120 molecules in outer space have about ¾ carbon in them; carbon is a natural form of life; more abundant than silicon and magnesium

Carbon for Life

Hydrogen bonding in DNA, Redox reaction for molecules, Waste (breathing out CO2); Carbon is easy to expel while Silicon is not (its rock)

Silicon

Mostly locked into quartz and rock

Organic Molecules for life

Amino acids, nucleotides, sugars, lipids, ATP

Miller - Urey Experiment

Put H2O H2 CH4 and NH3 plus spark and created all 20 amino acids in an hour; Only works with no oxygen (early earth had NO oxygen first)

Murchison Meteorite

Confirmed 92 amino acids formed in space but mixed L and D forms, life on earth = L forms only

Energy Source

Lots of energy in the beginning of life; both prokaryotes and eurkaryotes showed to thrive in high temps

LUCA

Considered to be a high temp loving organism (thermophilic)

Polymerization

Cool dry surface preferred; mineral surface = monomers bind to surface in random patterns until they form a replication gene

Cell Formation

Amphiphilic molecules are enclosed by membrane to form other cell membranes; forms proto-cell membranes

RNA

RNA came before DNA; some RNA can bind to ATP (energy metabolism): rRNA, mRNA, tRNA show RNA to be a very early molecule (replication being the first gene and it replicating it self to produce others)

Cech and Altman

RNA can catalyze reactions not just store information

Fossils

99.9% of fossils are full mineral replacements mad of silica; dinosaur bones more than 66 mya are fully silica and heavy

Mold

Impressions, cast, filled in impressions/compressions = flattened fossils (leaf in shade)

Trace Fossils

Behavior evidence; Footprints, coprolites (poop); not the organism itself

Chemical Fossils

Petroleum; from ancient marine single cell organisms

Lagerstatten

Fossil sites that show a diversity of organisms with great preservation `

Burgess shale (australia)

about 520 mya; Cambrian (paleozoic)

Chengliang (china)

about 525 mya, Cambrian (paleozoic)

Solnhofen (germnay)

about 150 mya Jurassic (mesozoic)

Jeho/liaoning (china)

Cretaceous (meszoic)

Preservation of Organisms

Favored large with hard bodies at low elevations, shallow marine is the best; dry area preserve best

Precambrian Life

Bacteria were both in water and land; Major groups: Archaea Bacteria, Eukaryotes

Before Eukaryotoes

came plastids (plants) and mitochondria (animals); both endosymbiotic events

Oldest covincing animal fossil

Sponge from 890 mya, basal, closest living relative = chonaflagellates

Late Precambrian fossils

Diploblastic organism (Cnidarians)

The Phanerozoic Era

Hold the Paleozoic Era (539-252 mya) which shows fossils animals phyla, plants, invertebrates, land vertebrates

Land plant Origin

Paleozoic era, came from algae, bryophytes (nonvascular), ferns (vascular) angiosperms and gymnosperms; plant structure shows the adaption of plants in their environment (e.g. lignin)

Carboniferous Period

lots of carbon from plants; oxygen levels were 21% in Cambrian, then went to 35% in Carboniferous (plant photosynthesis) back to 21%

High Oxygen levels

Gigsntism in insects

First invertebrates

Silurian period 400 mya; scavengers and predators only; could not digest lignin

Devionian

380 mya; spiders centipedes, millipedes on land

Herbivory

280 mya, ability to digest lignin, required gut bacteria to breakdown cellulose

Arthropods

exoskeleton (chitin+protein) → stops water loss, jointed legs → support w/o water buoyancy, spiracles/trachea → breathing air, internal fertilization

Origin of Tetrapods

Lobe-finned with strongest fins were able to adapt easier on land in times of drought

Different Types of FIsh

Jawless (lamprey and hagfish), cartiliagenous (sharks and rays), bony fish (lung fish and coelacanth)

Amphibians

Jointed Fins (4 fingers, 5 toes); first terrestrial vertebrates, have lungs but breath through skin, frogs, salamanders, caecilians

Amniotes

Comes from amniotic egg which protects and nourishes embryo; Reptiles (including birds) and mammals

Reptiles

310 million years ago; Hylonomus: Oldest reptile fossil

End Permian exticntion

99% species gone, 55% marine genera; Volcanic gas causing ocean acidification and deoxygenation; Greatest extinction in Earth’s history: End of Paleozoic: Pangaea fully together

Mesozoic Era

252-66 mya; Domination of reptiles and gymnosperms

Dinosaurs

Upright posture, Digitigrade (3 toes down); 2 groups: Saurischians and Ornithischians

Saurischians

Herbivores and Carnivores; Theropods (T-rex, velociraptor, sauropods (long neck)

Orinithischians

herbivores only, often armored (stegosaurus, ankylosaurus

Dinosaur physiology

big dinos prob retained heat just from size; herbivores → fermenting plants = extra body heat; bone blood flow studies → bigger vessel channels = more blood flow = more mammal-like; polar dinosaur fossils → dark/cold months → either hibernated or warm enough to stay active; feathers → found on lots of non-flying dinosaurs → not for flight → for insulation, like birds today

Crocodilians and Turtles

Triassic; armed above and below; relative of archosaurs`

Marine reptiles

NOT dinosaurs, all extinct by 66mya; mosasaurs (related to monitor lizards); ichthyosaurs (marlin-shaped); plesiosaurs (long neck)

Flying vertebrates

bats, birds, reptiles; pterosaurs (not dinosaur); first bird - archaeopteryx (150 mya) = birds are living dinosaurs; hollowed bones for lighter flight; feathers from keratin

Mammals

200 mya; heterdont teeth (different types); hair; lower jar bone to ear; 3 groups: Monotremes, Marsupials, Placentals

Monotremes

Lay eggs

Marsupials

pouch young

Planentals

placenta