precambrian, paleozoic, mesozoic, cenozoic
cambrian, ordovician, silurian, devonian, carboniferous, permian, triassic, jurassic, cretaceous, paleocene, eocene, oligocene, miocene, pliocene, pleistocene, holocene
Paleo+Meso+Ceno zoic eras - everything but the precambrian.
Are the time divisions such as paleozoic, mesozoic, cenozoic equal in length?
This time period consists of 80% of earth history
around 4.5 billion years old
First fossils are around
3 billion years ago
Origin of animal phyla, invasion of land
age of reptiles, origin of angiosperms, birds
age of mammals
What constitutes 0.002% of earth history
proposed the idea of maritime climate vs. mainland climate - beach and mainland climates differ - also the idea of continental drift, that land masses rest on tectonic plates
Movement of land masses on tectonic plates
Describes the land formation on earth from the Triassic change to late Jurassic
In triassic, pangaea was formed and upon transitioning to late Jurassic Laurasia (North America, Europe) and Gondwanaland (other continents and India) were formed Later, Gondwana, which was South AM, Africa, Australia, Antartica and India was formed.
What is the evidence for continental drift from geographic distributions?
Gondwanan distributions, that in pangaea species originated, but when pangaea split up into laurasia and gondwanaland - we see evidence of the initial split followed by speciation. Idea that modern taxa, ratite birds, marsupials, and lungfish are in every continent but in different forms
Most direct evidence on evolutionary history
_____ fossil species have been taxonomically described
greater than 250,000
paleotology vs. neontology
neontology is scientists of now, studying present. Paleotology studies past. Idea that the age of the fossils consisted of mode of earth's time and should be considered as most important.
inferring structure of organisms, communities from fossil remains
three types of sedimentary rock that contain most fossils
limestone, sandstone, shale
How to determine absolute fossil age?
Evaluate decay of radioactive materials in igneous rocks.
element specific rate for half of material to decay to different substances
Is uranium 235 a good indicator of fossil history?
U 235 has a long half life of 700 million years, which is good for old fossils, but really bad for new ones
How to calculate half life?
Determine proportion of total that are parent atoms - 1/N. 2^X = N. X = number of half lives.
Carbon 14 dating
better than Uranium for more recent fossils. Divide C14 in fossil by C14 in air = 1 N
mineralized evidence of dead organisms
due to precipitation of dissolved minerals in cells following burial in sediments, often preserving intricate details.
dinosaur bones, petrified wood, and club moss vascular tissues are examples of
2 dimensional fossils of material buried prior to decomposition, formed by flattening under pressure- Leaf fossils
shape taken by minerals invading, hardening as organism decays
impression of organism hardened into stone
fossils that reflect organismal behavior - how we learn about lifestyles. I.e dinosaur tracks, gizzard stones, and poop
A leaf with a deep puncture in it presumably from a bird in fossil form is example of
dino tracks and poop are examples of
icthyosaur example of trace fossils
showed ichtyosaurs birthing live baby.
Nest of dino eggs would be
fossilized tree resin - preserves exquisite detail. Preserves things, O2 can't contact them.
Chemists say that DNA lasts less than
100 thousand years.
DNA has been recovered from specimens up to ___ years old
Why will the fossil record never be complete?
Because every organism that has ever lived has not been completely fossilized - hard to tell where, when things die, and was found by humans next. So we have gaps - which represent either us not having fossils or the fossils could not be preserved from that time.
some taxa not preserved. How no strata form for a time period and thus fossils aren't preserved
unequal representation of environments in strata, how one type of environment can preserve better. I.e marine envs. preserve better than terrestrial
fossils that end up in strata from the wrong time, Idea that vertically separated strata may mix, and **** up accurate measurements
fossils not preserved at death site - they may wash downstream, or be dragged by predators
limited stratigraphic access
some strata are rarely exposed and studied cause they are too deep.
tendency for some taxa, individuals, structures to fossilize more readily than others. Bigger tougher tissues have less degradation and better fossilization. Plants rarely preserved whole, while shelled animals rock the house.
rotating barrel with invertebrate taxa, experiment used to measure rate of degradation.
What parts of plant preserve easily?
some taxa are more popular to study - dinos over insects. And some areas are more popular and accessible. North America has easier to find fossils
2 main problems with fossil taxonomy
1. Difficulty identifying different species from few or incomplete specimens. Example of conodonts, eel like species with crazy jaws that people thought were different species. Examples of early mammals, plants and pollen,
Idea that a species remains relatively constant and doesn't evolve thoughout time. 2. Chronospecies: anatomically distinguishable fossils of one lineage from different strata - bacteria evolving into bird - where do you call them different species?
different traits have different patterns of evolution- example of shape changes in foraminifera
anatomically distinguishable fossils of one lineage from different strata.
first fossils were
prokaryotes 3.5 billion years ago in oldest sedimentary rocks, indicating life possibly beforehand.
How does phylogeny support the endosymbiont hypothesis
you have monophyly of eubacteria and eukaryotes, and achaebacteria which branches off. We see mtDNA in eubacteria side - which could be that organelles were prokaryotic before they were eukaryotic. Showed that mtDNA of eukaryote was similar to actual bacteria
example of evolving endosymbiont theory
aphids with bacteria - bacteria are losing much of their genome in order to occur inside the bacteria.
a huge fauna of organisms that we have no idea how they are related to anything.
Life on earth, to single eukaryotic cells, to origin of diverse body plans, diversification
1st 2.5 bya, next 700 myr, next 100 myr, last 500 myr
1st fossils of most animal phyla are from
Bunch of new body plans and species originate within 10 my of 530 my ago.
Reasons for the cambrian explosion
1. Taxa evolved in response to environmental change (increase in O2 levels) 2. taxa existed earlier, but couldn't fossilize (skeletons)
Why no major body plans since the cambrian explosion?
Possible that there is a lack of free niches - competition.
First shellfish and corals
First land plants
first mammallike reptiles
first flowering plants
First modern humans
***Name each era, with each period inside it and each epoch
4 eras 1. Precambrian 2. Paleozoic 3. Mesozoic 4. Cenozoic Precambrian -don't need to know - Paleozoic has all periods inside it - cambrian, ordovician, silurian, devonian, carboniferous, permian. Then comes Mesozoic - with the Triassic, Jurassic, Cretaceous periods. Then comes cenozoic, the most complex - with two periods, tertiary then quaternary. In tertiary period - we have paleocene, eocene, oligocene,miocene,pliocene. then in quaternary we have pleistocene and holocene
Good tool to remember periods, eras and epochs
So eras = PC,P,M,C Periods = COSDCPTJCQT epochs= peompph
***How to determine age of a fossil
1. Sample igneous rocks near fossil. 2. Determine proportion of total atoms that are the originally parent atoms. 1/N. 2^x = N, where x= # half lives. Solve for x and multiply by half life.
1st fossils of most animal phyla are from the
Cambrian explosion, start of paleozoic era
1st fossils of most animal phyla are from Cambrian. All appear within 10 My of 530 My ago. Body plans already complex. Some of the plans that originated there are now extinct.
Main reasons to explain Cambrian explosion
1. Organisms all had complex forms at same time - taxa evolved fast in response to environmental change i.e sudden increase in O2 levels. 2. They couldn't fossilize before this period until skeletons that actually could fossilize were made. 3. No body forms since then because of lack of free niches.
Burgess Shale fauna
remarkably well preserved site in British Columbia where there is an amazing record of cambrian life. Soft parts, taxa preserved , making this more complete.
Examples of taxa in the burgess shale
sea pen, primitive arthropods, priapulid worm, chordate. onychophoran. polychaete worm.
illustrates organisms that were once dominant, and now they are extinct. Examples are trilobites, ammonoids, crinoids, brachiopods.
echinoderm (like starfish)
Limestone fossils from Nashville come from this period
Age of fish
Devonian is known as the
age of fish
Explain fish evolution
Fish show progression from jawless fish to jawed fish, from soft to bony fish. Recent cenozoic radiation means that fish such as the teleosts are constantly getting more and more diverse.
the first jawless fish
lobe finned amphibian - ancestor to lungfish
Modern bony fishes are
teleosts are ___% of fish today
lobe finned amphibian - coelocanth is a living fossil.
Late devonian period associated with
move to land, so tetrapods existed.
1st creatures that invaded land were
amphibians evolved from sarcopterygians
What evidence do we have of sarcopterygians
great fossil record of intermediate taxa, traits.
We have great fossil evidence and intermediates for
the evolution of tetrapod limbs from lobe fins. Fossils show many steps of major evolutionary transition
Mammal like reptiles were dominant in
In addition to evolution of tetrapod limbs from lobe fins, what other thing do we have great evidence for?
The transition from reptiles to mammals. We see trend towards larger brain cases, more erect, jaw,earbones. and tooth specialization.
1st true mammals occurred in, but were
late triassic, but were small, uncommon, ecologically unimportant homogeneous insectivores.
___ era commonly associated with dinosaurs
Dinosaurs were dominant land vertebrates when...
late triassic to end of cretaceous.
dinosaurs were mostly, but 1 clade was
herbivorous, 1 clade carnivorous
Some new ideas about dinosaur behavior
erect posture, active - 1. POSSIBLY WARM BLOODED 2. Behaviorally complex with things like sociality and maternal care. Sex selection too.
2 major groups of dinosaurs
1. Saurischians-lizard hipped. 2. ornithischians - bird hipped. These are sister taxa, so hard to tell if dinos are in a clade, or if they had two evolutionary origins
three types of marine reptiles that diversified at end of triassic
1. mososaurus - true lizards 2. plesiosaurs - more than 5 digits 3. ichtyosaurs - had dorsal fins, thought to evolve convergently with dolphins, sharks.
List the major events in plant evolution
1. chlorophyll a,b developed - we get algae from it. 2. Then cuticle evolves in ordovician, we get mosses from it. 3. Vascular tissue evolves in silurian, we get club moss horsetails, and ferns from it. 4. Seeds evolve in carboniferous and we get Cycads, ginkgo, conifers. 5. Flowers evolve in cretaceous and we have now have angiosperms. So 1. Chlorophyll 2. Cuticle 3. Vascular tissue 4. Seeds 5. Flowers
1st insects appeared in
Insects are in hexopoda, what are the closest insect relatives?
myriapoda - had chitinous exoskels and amber.
Most insect orders in place by the
Did angiosperm evolution drive insect diversification?
Only for certain species. Idea was that you may have new niches to fill, and so you examine diversity of insect species around that time. They actually found that rate is slower following flowers for diversification, so we don't have an overall positive effects - but rate increases for some groups like bees, flies, moths, and beetles.
Birds apparently evolved from
Bird evolution/ flight
Historically controversial, many ideas. Birds apparently evolved from dromaeosaurs/therapod dinosaurs. And much discovery has gone on in the past 10-20 years in new insights.
What do we see as the main transition species for bird evolution
Archaeopteryx was the first birdlike dinosaur. Descended from dromaeosaurs, Had many features similar to modern birds such as 3 toed foot with 4th reversed toe. Unique leg joint. diapsid two holed skull, hollow bones, long slender tail, heavy skull. Modern birds tend to have reduced fused versions of all these things.
Archaeopteryx was dominant when
diversifying a species through adapting to the changes in the environment, such as new niches...
dino extinction led to mammalian
Most modern orders of Mammals by
paleocene, early eocene
Describe adaptive radiation of mammals
in the paleocene, early eocene - dinosaurs were gone, leaving niches for mammals to fill
Time when mammals were diverse
paleocene and early eocene onward
saber toothed tiger is example of
extinct mammal from cenozoic peroid.
Biggest land mammals
baluchitherium - a rhinocerid
a rhinocerid, biggest land mammals
bizarre horse relative
***Is macroevolution predictable? Explain why this might be so. Who pioneered this theory?
We observe convergent evolution - independent parallel mammal radiation - example of placental and marsupial lineages. We see the same types of forms evolving in both marsupial and placental analogs. We see saber tooth tigers, seal like, mole like, fish like taxa evolving more than once in different lineages. Stephen Jay Gould questioned this concept. Wondered if niches were "real"
Pleistocene famous for
ice ages occurred when?
end of permian, and quaternary
Last ice age was when?
What effect did Ice ages have on the the world?
Organisms moved in latitude, altitude to follow environment; across bridges like the icy Bering Strait. Some were cold adapted and settled in new places like the woolly mammoth and woolly rhino.
The last ice age had what major change to the world?
extinction of the megafauna.
***Big picture to evolution of marine inverts, plants, insects, tetrapods
We see general trend of increasing diversity across taxa.
Are cambrian plant taxa around today?
Need to get slide on primate phylogeny
Chimps and bonobos are around ___% similar to humans
The closest relatives of chimp, bonobos, and gorillas and humans all came from
East Africa noted for
origin of many primate species.
What recent discovery questions that idea that origin of primates was in east africa
ancient fossil discovered in Chad, conflicts with rift valley origins.
Do we have a good human fossil record?
Yes. Many species, many intermediate forms with trends-but most remains are fragmentary
Oldest hominids estimated age
Until recently, 4.4 my ago. New estimates say oldest hominids were 6 my old. Phylogeny is controversial.
Paranthropus is another name for
List the major trends that characterize the evolution of hominids
increasing body size, increasing brain size. 5 digits, increasing digit mobility. flat nails instead of claws, bipedalism, decreased nose length, decreased canine tooth length. Increased vision, decreased olfaction.
more prominent in human with evolutionary time
One of the most primitive hominids from east Africa. - Protruding face, large canines, small brain, longer arms with curved digits, very apelike w/ tree climbing, but BIPEDAL.
Lucy is an example of
another old hominid lineage from e. Africa. not our ancestors though. They were large, burly, with large jaw and molars. HAD THE BIGGEST HOMINID TEETH AND USED STONE/BONE TOOLS.
Had the biggest hominid teeth and used stone/bone tools
from e. s. Africa. One of the great missing links. Had a bigger brain, less protruding face, apelike limb proportions, but better bipedalism. OUR PRESUMED ANCESTOR that used stone tools for cutting/crushing w/ a single blow.
Used stone tools for crushing/cutting with a single bloe
presumed to be the missing link ancestor to humans
colonised Asia 1 mya. Had round cranium w/ smaller teeth and brow ridge. FIRE 0.5 mya. - COEXISTED with us.
Which homo form created fire and is thought to have coexisted with us?
older, African form believed ancestral to us. Heavy tool use 1.5 mya-200000 yrs ago. Made symmetrical tools like hand axes, and these designs were conserved for a million years.
Homo sapiens have existed since
300k yrs ago.
300k yrs ago. Bigger brain. Modern humans around 120k yrs ago.
"Anatomically modern" humans
120 k yrs ago
refers to older "archaic forms"
diversified tools and techniques. Arrows/harpoons/chisels, needles. Paintings as well. Had independnt Asian and African origins.
If you see a painting in a cave of a previous hominid which is it most likely to be
Single species hypothesis
That only 1 hominid species could exist at a time because their niches are the same. This was popular before a more complete fossil record came to be
Coexistence of hominid species
We now know that 4 species lived at same time and place around 1.8 mya in north Kenya. So huge thing that multiple species are coexisting. Big factor in racism.
A./P. boisei - H. ergaster - H. habilus - H. rudolfesnsis
coexisted at the same time in Northern Kenya
200-40 kya in Europe and Asia. Had dense bones, skulls and brows. Often depicted as brutes but were fully upright, big brains and good tool makers. They shaped stone core before making blade. They made first specialized spear tips. Also first examples of burial.
First examples of human burial/religion in
Made 1st spear tips
Modern humans coexisted with neanderthals, but what happened?
Modern humans quickly replaced them about 40 kya. People think 1. Neanderthals were ill adapted and moderns won 2. Neanderthals were exterminated by modern humans 3. That neanderthals genetically interbred with modern humans, assimilated by moderns. We have evidence of hybridization in fossils of Portuguese child that lived after Neanderthal extinction. Long presence of neanderthal genes, means that there was considerable interbreeding.
There is considerable controversy about the transition from H. ergaster/erectus to H. sapiens
4 models - African replacement, hybridization and assimilation, multiregional evolution, candelabra
Model about how H. ergaster/erectus evolved to H. sapiens. H. sapiens evolved in Africa then migrated to Eurasia, replacing local forms like H. ergaster/erectus WITHOUT Hybridizing with them
Hybridization and assimilation
Model of how H. sapiens arose. Same as African replacement model, where H. sapiens evolved in Africa, then moved to Eurasia but HYBRIDIZED with H. ergaster/erectus and establish themselves
Model of how H. sapiens arose. Idea that H. sapiens evolved in Europe, Africa, and Asia at the same time, while gene flow maintained these populations as a single species.
Model of how H. sapiens arose. Idea that H. sapiens evolved in Europe, Africa, Asia at same time, but no gene flow so independent origins of H. sapiens. PROVEN FALSE.
Present genetic and anatomical evidence suggests that all modern people descended from....... all modern non Africans are descended from...... and thus.....
All modern peoples descended from African ancestors. All modern non Africans are descended from H. sapiens who left Africa within the last few hundred thousand years. And thus racial differences have evolved since then.
Migration pattern of h. sapiens
started in Africa, then went to Asia and Europe, then went to Australia and New World via land bridges. Then later on to South America. African origins supported by mtDNA.
Genetically, how do we know that h. sapiens originated in Africa
African origins are supported by mtDNA. African sequences are older.
How can we tell the progression of h. sapiens moving from africa outward
mtDNA sequences in closer regions are similar.
Humans have greater genetic variation as a species than do related ape species. T/F
False. Humans have less genetic variation as a species than do related ape species. Humans are relatively homogenous, suggests possible recent bottleneck.
Idea that humans have similar mtDNA because of a recent population bottleneck. Humans are relatively homogenous.
Describe variation patterns in humans
Among populations, variation is low, less than that among mammal subspecies. But within population variation is high. Populations show frequency, not fixed differences.
In humans, 85% of variation is
In humans 8% of variation is
Are patterns of genetic variation = races?
no. Pigmentation and genetic differences not strongly correlated.
You observe many races of individuals, does that mean that we have large genetic variation?
Skin color is a human adaptation more than an estimate of variation. T/F
people that live in UV all year round near equation synth it all the time, but near poles, Not so much. Adaptation.
__% of species are extinct
taxonomic diversification rate
rate of origin-rate of extinction
Is extinction well known?>
Not a well understood process
A high number of species with large geographic distribution can provide resistance to extinction?
extinction via replacement by superior competitor
The Great American Interchange
Idea that when S. America fused with N. America via panama, species from both continents crossed the land bridge and settled in other continent. However, from prior competition with Eurasia, N. American species were better competitors and drove some of the S. American species extinct. So, we see more species in South America that orginated from North, than seeing things in North that originate from South.
Genetic drift leads to
loss of heterozygosity
Effective population size
the number of individuals in an ideal population (in which every adult reproduces, in which the rate of genetic drift would be the same as it is in the actual population.
Colonization of new habitat by few individuals whose allele frequencies are not representative of the population
Genetic drift increases the frequency of colorblindedness.
Equation for New alleles created by mutation in each generative
Equation for chance of new allele drifting to fixation
x/2n ------- really it is 1/2N
Equation for number of new alleles that are created by mutation and are destined to drift to fixation is
2Nv x 1/2N = v v = neutral rate of evolution at the locus is equal to mutation rate.
Neutral theory of molecular evolution
1. Vast majority of base substitutions are neutral. rate of evolution = v 2. Size of population has no role on fixation of allele.
sampling error in the production of offspring genotypes from the parental gene pool that results in random changes in allele frequencies.
Drift leads to .... and loss of
pop divergence, loss of heterozygosity
Explain why some regions evolve faster than others, and how neutral theory attempts to reconcile this
- We know that k=v. We also say that k=fv, where f is the fraction of neutral mutations. This matters in regions like pseudogenes and important genes. - You see more evolution in pseudogenes because there are tons more selectively neutral mutations that could occur. In an actual protein, there aren't many sites you could mutate and get a selectively neutral mutation.
Inbreeding increases....but does not alter
Inbreeding increases homozygosity. Does not alter allele frequencies.
When inbreeding causes the same allele to be reproduced 2x in an individual from one grandparent
Do you ever have a heterozygote autozygote?
No because then the two alleles can't be the same.
Alleles identical by descent
Inbreeding may lead to reduced mean fitness if it generates offspring homozygous for deleterious alleles T/F?
Self fertilizing species typically exhibit lower levels of diversity T/F?
True, with inbreeding, can't have genetic variation
Heritability is the proportion of phenotypic variation that is due to additive genetic differences among individuals.
Selection results in change in allele frequencies and genotypic frequencies?
The fitness of a genotype is the average lifetime contribution of individuals of that genotype to the population after one or more generations
5 components of how organisms can be fitter than others
1. Viability selection 2. Sexual selection 3. Fecundity selection 4. Gametic selection 5. Compatibility selection
Antibiotic, enzyme that attacks bacterial cell walls (found in tears, saliva). Main point is where it convergently evolved in cows and monkeys to have new function due to more acidic stomach environment. So, lysosyme = convergent evolution in cows and monkeys
Sperm lysin gene of Abalone
A gene that varies greatly in the amount of nonsynonymous/synonymous mutations in different regions. Very species specific. Lysin creates a hole in the egg for sperm to pass through.
Just the idea of linkage - if you have a favorable gene, then it will be passed on more. And genes that are nearby that gene will be passed along more frequently.
SD in Drosophila
Segregation disorder in Drosophila - where in SD males, sperm are incapacited and SD sperm can fertilize.
Canine Transmissable Venereal Syndrome - infectious disease of dogs that is caused by a pathogenic lineage of cancerous cells. Transmitted from dog to dog. The tumor is thought to be a highly degenerate mammal.
What does the example of selecting the chicken breed with the highest yield do?
Selection at the population level vs. individual. Farmers wanted more eggs, so they thought they could breed chickens that were good at laying eggs- but there was a lot of infighting. So they selected the group with the highest yield, not the individuals. Greatly enhanced egg production and survival.
One side of phylogenetic tree has higher speciation rates than the other
One side of phylogenetic tree has longer survival times.
Example of where having this trait could be beneficial and detrimental to fitness at the same time
Sexual selection - where you could have bright colors and attract mates better, but you also attract more predators.
The operational sex ratio is usually male biased t/F
Females are a limiting resource for males t/F
Variation in mating success greater in females than males? T/F
False, variation in mating success greater among males than females.
Why is variation in mating success greater in males than females?
Because males can put out and make tons of babies without needing to care for them. Females can't do that. Example of elephant seals - we see where male elephant seals have harems of females.
8 Examples of competition for mates *****PROBS AN ESSAY QUESTION FOR ROKAS
1. same sex contests 2. Mate preference by opposite sex 3. scrambles 4. endurance rivalry (remaining reprod. active) 5. sperm competition 6. coercion 7. infanticide 8. antagonistic evolution
Examples of cooperation and altruism
Mole rats, very social mammals, all works are sterile, helping one female to lay eggs
activity that provides benefit to other and to the actor as well
activity that provides benefit to others but lowers the fitness of the actor
Give an example of cooperation
Long tailed manakins - subordinate bird performs leapfrogging display with dominant male. Once dominant male dies, then subordinate male can be dominant.
Inclusive fitness of an allele is comprised of both its direct fitness (effect of allele on individual) and its indirect fitness (effect of copies of allele on other individuals).
Selection based on inclusive fitness is called
_____ is one of the most important explanations of why altruism exists
Describe Hamilton's Rule
An altruistic trait can increase in frequency if the benefit (B) received by the donor's relatives, weighed by their relationship to donor (R) exceeds the costs (C) of the trait to the donor's fitness. R - coefficient of the relationship. Fraction of donor's genes that are identical by descent to any of recipients genes. So for a bro or sister r=1/2, cousin 1/4, half cousin 1/8.
Types of biological variation
1. sexual dimorphism 2. Genetic variation 3. Environmental variation 4. Developmental variation 5. Geographic races 6. Sympatric races 7. Good biological species 8. Hybridization
Good biological species
Completely RI pops, with fixed genetic differences between species, can't mate.
limited interbreeding between normally reproductively isolated species
region where species ranges meet.
reduced capacity for gene flow between populations
positive assortative mating
increased mating b/w similar phenotypes
Examples of behavioral isolation
lacewings, fireflies, beetles
On average at D > 0.4, how long does it take for speciation to occur
speciation of 2 broadly distributed populations due to emergence of major extrinsic barrier.
Examples of peripatric speciation
kingfishers and hawaiian drosophila
example of parapatric speciation
Sympatric speciation requires
genetic linkage between habitat use and mate preference, knowledge of geographic origins
more than 3.5 billion years ago
prokaryotes are monophyletic T/F?
The cenozoic era began ____ yrs ago?
The mesozoic era began ____ yrs ago?
The paleozoic era began ____ yrs ago?
The precambrian began ____ yrs ago
COSDCP. Cambrian, ordovician, silurian, devonian, carboniferous, permian
PEOMPPH - Paleocene, eocene, oligocene, miocene, pliocene/////pleistocene, holocene
***What happened in the paleozoic era, origin of what
Origin of shellfish and corals ----- fish ---land plants ---insects and tetrapods ----reptiles/mammallike reptiles ----
***What happened in the mesozoic era, origin of ?
Mesozoic - first dinosaurs, mammals, birds, angiosperms
***What happened in the cenozoic era, origin of
first horses,whales,monkey,apes,hominids, and modern humans
What happened in the cambrian period?
What happened in the ordovician period?
first fish - all those nashville fossils too
What happened in the silurian
first land plants
What happened in the Devonian?
first insects and tetrapods - rapid expansion of fish diversity
What happened in the carboniferous?
first reptiles and mammal like reptiles
What happened in the permian?
What happened in the Triassic?
First dinosaurs and first mammals
What happened in the Jurassic?
First birds, Archaeopteryx
What happened in the Cretaceous
What happened in the Eocene?
First horses, whales, and monkey
What happened in the Oligocene
What happened in the miocene
first hominids - around 23 mya
What happened in pleistocene
first modern humans around 1.6 mya
Precambrian consists of 70% of earth history?
Humans consists of 1% of earth history?
False 0.002% of earth history
Pangaea formed in, split into Laurasia and Gondwanaland in ___
Triassic, split in late Jurassic
North America, Eurasia
south america,africa, india, anartica,australia
evidence for conditions in India.
Glaciers used to occur in India T/F
Two main forms of amber are
You can recover DNA from specimens
50,000 years old
***Name some things that can prevent us from knowing everything about a fossil
1. stratigraphic incompleteness 2. stratigraphic bias 3. temporal infidelity 4. spatial infidelity 5. limited stratigraphic access 6. preservation bia 7. research bias 8. chronospecies
Mosaic evolution ****s up what
makes deciding chronospecies harder, because you have multiple traits evolving differently so you can't tell when new species arrive
Ediacaran fauna occurred in what era
Cambrian explosion occurred when?
Burgess shale fauna existed when?
trilobites and ammonoids were popular in this period
Describe the basic pathway of fish evolution
Fish first appeared in the ordovician period, and really branched out in the Devonian. The first jawless first were the ostracoderms which later evolved into the placoderms with jaws and armor. Then several other fish branches like the sarcopterygians (ancestors to the lungfish) and teleosts developed. The teleosts have gone on and diversified greatly. We also have the chondrosteans and holosteans
Move to land was in what era?
First amphibians evolved from, how
sarcopterygians - went from lobe fin to tetrapod limb.
Mammal like reptiles were created in, and diversified in
created in carboniferous, diversified in permian and triassic
1st true mammals
Mososaurs, plesiosaurs, ichtyosaurs all are ..... that diversified at end of
Define plant evolution through time
Evolved chlorophyll then cuticle - giving mosses, then evolving vascular tissue - giving club moss, horsetails and ferns - evolved seeds so cycads, ginkgo, and conifers, then flowers and angiosperms came about.
major predatory bird in paleocene - gone now
When did the mammalian radiation begin?
Paleocene - think Paleozoic as beginning of complex life Mesozoic as beginning of dinosaurs, and Cenozoic as mammals
ice ages occurred in the
Common ancestor to chimps dated when?
When did all the species of hominids coexist in Kenya?
Pleistocene - 18.mya
Who were the neanderthals?
Hominid that lived 200-40 kya in Europe and Asia. Dense bones, skulls, large brows. Portrayed as brutes, but good tool makers with big brains, they used specialized weapons and had some of the first instances of burial and jewelry. Modern humans coexisted with them - but abruptly replaced them 40 kya. Hypothesis for why they died out were 1. ill adapted and outcompeted 2. exterminated by h. sapiens 3. interbred with h. sapiens.
What are the main hypothesis about how H. sapiens arose?
1. African replacement 2. Hybridization and Assimilation 3. Multiregional evolution 4. candelabra.