Geo 105 Exam 2
What characteristics do you share with lobe fin fishes?
arm bones
How does the transition from Lobefin Fishes to Amphibians supports the Darwin's theory of descent with modification? (IMPORTANT - you will see this)
bones on lobefin fish shifted over time to become vital components of the arm.
Ostracoderms
"Shell skinned"; armored jawless fish of the Paleozoic; first to use gills for respiration instead of feeding. the armored jawless fishes of the Paleozoic.
Anomalocaris
"abnormal shrimp"; thought to be the first predator. Extinct shrimp like life form closely related to Arthropoda. It was a top predator that rules during the Cambrian period
Megalodon
"big tooth"; an extinct species of shark that lived during the Cenozoic era. Giant shark of sc. Fed on whales
Eryops
"drawn out skull" because most of its skull is in front of its eyes; semi-aquatic amphibian Eryops is the most famous Paleozoic amphibian and an interesting example of natural engineering. Having evolved from lobe-finned fish, Eryops retained many fish-like characteristics but adapted them for land life.
Describe the first land community. When did it appear?
consisted of mostly amphibians adventuring on land. During Carboniferous period.
The earliest occurrence of reptiles in the fossil record occurs during what time? To which amphibian group are reptiles most closely related
during carboniferous. Oldest reptile founded trapped in a tree stump.
Stromatolites
earliest form of life on earth structures formed in shallow water by the accretion and cementation of sedimentary grains of microorganisms, especially cyanobacteria (blue green alge)
What geological factors leads to a hothouse climate?
-56 MYA; period where the earth had no ice; temperatures were very high- described as "feverish;" was caused by surge of carbon; tectonic plates were very active during this time period; didn't absorb for 150,000 years
Why were the reptiles so much more successful at living on land than the amphibians?
-Amphibians have a skin that requires constant moisture and can only stay out of water for a certain period of time; reptiles have thick, coarse, dry skin that is better for living on land -They also have stronger legs that do not need buoyancy of water -Amphibian eggs require water or they will dry out and reptiles can lay eggs on dry land
Why do some think there are only three kinds of metazoans?
-Three types of metazoans: asymmetrical, bilateral, radial -Hox gene: master regulatory gene that control structure; in all metazoans -Regulate body structures and we only have 3 types of mutations from this gene
What are the three major groups of reptile? (Hint: skull type)
1. anapsid: no additional opening behind the orbit of the eye. 2. synapsid: one opening behind the orbit of the eye. 3. diapsid: two openings behind the orbit of the eye.
Lateral Line
A faint line visible on both sides of a fish's body that runs the length of the body and marks the location of sense organs that detect vibrations in water only functional in water.
Eusthenopteron
A genus of prehistoric lobe-finned fishes; close to tetrapods
Amphioxus
A marine invertebrate found in soft substrates in shallow sea; the model organism to study the development of vertebrates Chordate. Intermediate form between invertebrates. Notochord. Slender fish without eyes or definite head. Used gills to filter food particles. Swim near the bottom both ends are tapered.
What is the great oxygenation event? What was the importance of that event?
A rapid increase of oxygen. without it there would be no multicellular organisms and continents would look different.
Coelacanths
A rare order of fish; closely related to lungfish, reptiles and mammals. Name for the grouping of 2 similar fish. The West Indian Ocean coelacanth and the Indonesian. Oldest known lineage of honey fish and closely related to lobe-finned fish and tetrapods
What is snowball earth?
A severe ice age that occurred 700 million years ago and covered the Earth from pole to pole
Cooksonia
An extinct grouping of primitive land plants; most types come from Britain worlds oldest known underwater plant, mushroom shaped and had vascular characteristics
Explain how a symbiotic relationship among Proterozoic prokaryotes may have given rise to eukaryotes.
Andosymbiosis - oxygen and energy - one cell ingested by another and individually grew and gained internal organs. Evolution of a eukaryote by two prokaryotes living together.
Hallucigenia
Animal with toothpick like spines found in Burgess Shale Cambrian animal known from articulated fossils in exceptional Burgess Shale-type deposits. Had 14 "tentacles" that seemed to have a mouth at each tip. These were believed to be feeding aids. 3 Cm long
BIF
Banded iron formation was laid down before 3.5-1.8 billion years ago during the Archean Eon. It consists of black iron minerals and red-brown chert. Oxidized iron deposited produced BIF
What evidence indicates that eukaryotic cells had evolved over 2 billion years ago?
Because fossils are big and you can see them without a microscope
Why does Earth have seasons?
Because the earth is tilted at 23 degrees and spins on an axis. This means either the northern hemisphere or southern hemisphere is tilted closer to the sun and rotates throughout the year creating different seasons.
Did limbs and air breathing occur before or after tetrapods emerged to live on land? Please explain.
Before. Panderichthys developed first external nostril used to breath in shallow, low oxygen ponds. Limbs began to shaped arm like while still a fish. muscles, skeleton, and other shit needed to form first before they could actually walk on land.
Discuss the possible causes for the increase of diversity of life during the Cambrian.
Cambrian explosion: a. increased geologic activity: more volcanic eruptions, sea level rise (made more shallow water environments) b. Increased food supply: burrowing releases nutrients c. oxygen level increases d. hox genes e. evolution of eyes, important of predators f. complex community development: predator-prey interactions
What characteristics are common to all chordates?
Chordates, including humans, all have four common evolutionary characteristics-a dorsal nerve cord, a notochord, pharyngeal gill slits, and a post-anal tail. However, when you look at humans you only see the nerve cord.
Tetrapods
Comprises the first four-limbed vertebrates and their descendants
Archaea
Domain consisting of unicellular prokaryotes that have cell walls. oldest fossil period any group of single celled prokaryotic organisms
What climatic/atmospheric conditions enable insects of the Carboniferous Period to grow so large?
During this time period due to the growth of rainforests; we see increased oxygen production; this enables insects and other animals to grow larger and flourish
C. Lyell
Father of modern geology. Wrote the first book. Created the concept of uniformitarianism
Tikaalik
Fish that developed adaptations to the oxygen-poor shallow-water habitats which led to evolution of tetrapods.transition fossil, flexible neck, flat head, fin at the end of the arm
What are Hox genes and why these genes so important in the evolution of metazoans?
Found within all Metazoans; Master (regulatory) genes; Control Structural Genes; determine form, number, and structure. they decide which characteristics should be produced and its import for evolution since metazoans will have some of the same characteristics so we can trace back.
Lung Fish
Freshwater fish belonging to the subclass Dipnoi; distinguished by their ability to breathe air and has a well-developed internal skeleton the side fins of the lung fish are the same bones that create arms and legs.
DNA
Fundamental hereditary material of all living organisms. A molecule encoding the genetic instructions used for development
What climatic event led to the dominance of reptiles and decline of amphibians?
Growth of rainforest → tropical climate; more oxygen in air allows for animals to thrive on land; amphibians start to go extinct permian
What is the effect of shrinking sea ice on global temperatures? Why?
HIGHER WATER LVLS. LESS ICE, LESS SUNLIGHT REFLECTED BACK INTO SPACE. HOTTER CLIMATE.
How has human activities altered the chemistry of Earth's Atmosphere? How do these changes alter the Earth's climate?
HUMANS BURN FOSSIL FUELS. RE-RELEASES STORED CARBON INTO ATMOSPHERE(GREENHOUSE GASSES)
What was Pikaia and what is its importance today?
Humans exsist because Pikaia survived the Burgess decimation Pikaia is an example of an organism with similiar characteristics of humans. For Example: *notochord- rod like structure, resembles spine *gills- resemble internal gas exchange *single dorsal nerve cord on the top of brain
Ichthyostega
Ichthyostega is an early tetrapod genus that lived at the end of the Upper Devonian period. It was a labyrinthodont, one of the first tetrapods in the fossil record.
What is the importance of Tiktaalik and Panderichthys?
first animals to move onto land. Amphibians.
How did an increase in geological activity at the start of the Cambrian contribute to an increase in species diversity?
Increased geologic activity casued volcanic eruptions which increased CO2 levels and made temperatures warmer. This caused sea levels to rise, making more shallow water environments.
Why are Extinctions important?
It allows the evolution of new species to replace the species which have gone extinct. The new species are often more evolved than the ones which went extinct.
What is the Burgess Shale fauna?
It contains Cambrian fossils (over 100,000 fossils) of more than 130 animal species. It was very complex community of animal species. There was a huge variety of body forms. Many "experimental" body plans, which of many are now extinct. It is an example descent with modification.
What is the Mistaken Point fauna? What is the importance of this fauna?
It is a marine environment and the water is 2000M. It is found on the edge of continent. This structure contains multiple fossils, holdfasts and branching stuctures.
What was the importance of the Ediacaran fauna?
It is first ecosystem to be discovered in earth history. It is an integrated ecosystem. It was dominated by filer feeding organisms. There were very low oxygen
What is the importance of the Little Shelly Fauna?
It is the first appearance of skeletonized taxa in the rock record.
Know the times of the following firsts: jawless fish, sharks, land plants, lobe-fin fishes, amphibians, reptiles, trilobites, worms, and Therapsid.
Jawless fish: 480 MYA caledonian -Sharks: 420 MYA Silurian -Land plants: 420 MYA Silurian -Lobe-fin fish: 415 MYA devonian -Amphibians: 375 MYA Devonian -Reptiles: 340 MYA Amniote -Trilobites: 521 MYA Cambrian -Worms: -Therapsid: 275 MYA Permian
Discuss the evolution of shark teeth.
Jaws come from gill arch supports Evolution remodels exsisting structures (descent with modification) Sharks and bony fishes have jaws with teeth, the teeth are replaced periodically.
How did jaws evolve? What is the importance of jaws?
Jaws evolved from gill arch supports
Discuss the change needed to the skeleton of Acanthostega to enable an animal to move on land.
first retard with fingers(8) and fish like tail.3
Describe the skull of Carboniferous age Amphibians.
first with small brain. third eye. lateral lines
Trace the changes in the vertebrate limb from lobefin fishes to reptile.
Lobefin fish first spotted with radius and ulna. Amphibians evolve to have more structure Start to form legs to waddle on Later amphibians can walk on land Reptiles evolved from amphibians and have more skeleton, thus better arms Reptiles develop better stride and supported skeleton form land movement
List and describe the problems that organisms had to overcome before they could inhabit the land. Why would vertebrate animals move to the land?
Low oxygen in the water and less competition on land for food. Safer on land too.
Today, Lungfishes live in South America, Africa, and Australia. Explain this distribution of Lungfishes.
Lungfishes can live without water due to Estivation. They can breathe air in water with low oxygen levels. They can dig holes in the mud where they build a nest and remain there until water levels rise again.
What characteristics do you share with Theriodonts?
Mammal-like reptiles that lived from the Middle Permian to the Middle Cretaceous; Theriodont jaws that made chewing a lot easier (similar to our teeth) back teeth were larger to chew meat; Synapsid skull-THIS IS WHAT WE HAVE
What phylum is best represented in the Burgess Shale Fauna?
Many were Anthropods most were unknown
How does flood basalts after the global climate?
Massive volcanism causes flood basalts form; long-term volcanism causes global warming; more carbon dioxide being added into the air = increased temperatures
What are metazoans and what characteristics do all metazoans have in common?
Metazoans are animals. There are 3 types: -asymmetrical -bilateral symmetry -radial symmetry They produce collagen (glue of life, only produced by metazoans) They all have Hox Genes which determine form , number, and structure Some metazoans include sponges, worms, and humans
How did the evolution of life alter the earth's physical environment?
Methane by archea, cyanobacteria produces oxygen, oxygen in the atmosphere created the ice age.
Uniformitarianism
Methodological assumptions that the laws of chemistry and physics have remained constant throughout the history of earth. the fact that the same natural laws that are in place today have always been true.The assumption that the same natural laws and processes that operate in the universe now have always operated
Little Shelly Fauna
Mineralized fossils with a nearly continuous record from the latest stages of the Ediacaran to the Early Cambrian period. The first appearance of skeletonized taxa in the rock record
How does mountain building effect the climate
Mountain building effect climate change because of ocean continental convergence. When mountains are formed it is from two convergent plates colliding which creates uplift and weathering affecting the climate.
Prokaryotic Cells
No membrane bound nucleus
Pikaia
Oldest chordate from middle Cambrian; only one with internal nerve cord (spine)
Acanthostega
One of the first vertebrate animals to have recognizable limbs. intermediate between lobe finned fish/ tetrapods
Opabinia
Opabinia, another small Cambrian critter, grew to eight centimeters (about three inches). This creature likely caught prey with the grasping claws of its long, tube-like proboscis and then stuffed the food into its mouth — much as an elephant uses its trunk.
What are examples of living and fossil jawless fishes?
Ostracoderm and Astraspis
What is Pangaea? What was the climate?
Pangea was a supercontinent that existed during the late paleozoic and early mesezoic era. It formed
Why does sexual reproduction lead to the genetic death of the parents?
Parents have made the new version of themselves
Name the metabolic process in which carbon dioxide and water combine into organic molecules, and oxygen is released as a waste product. What is its important?
Photosynthesis - creates oxygen
Describe and draw a very early fish. Label its features.
Pikaia is considered the first form of a fish- looked like a worm. It has 4 distinct features crucial to later fish. -Head distinct from its tail -bilateral symmetry (left side of body looks like the right side) -V shaped muscles -Nerve cord running down the body
How does supercontinents breakup?
Plate tectonics
What are causes of the long term (millions of years) swings between hothouse and icehouse conditions?
Plate tectonics
What predators were in the Burgess Shale Fauna? Why are predators an important factor for increasing species diversity? (Red Queen Hypothesis)
RQH- the host evolves defenses against the predator and the parasite, in tune evolved to overcome host defenses "arms race". Both sides must constantly evolve just to maintain the status quo.
What types of symmetry are found within metazoans?
Radial Symmetry No Symmetry (asymmetrical) Bilateral Symmetry
What is a lobefin as opposed to a ray-fin? (Draw or describe).
Ray Finned Fish are considered the most successful group of vertebrates, at least in water. They have multiple paired fins and are the largest single group of chordates. They exsisted in the Upper Silurian period, 408 MYA. A few distinguishing features: true bones, teeth fused with jaw bones, gas bladder. Dominant Genus of fishes since the Mesozoic. Lobefin Fish include Lungfish, Coelacanth, and Osteolepiforms. Single series of bone supports fin. Bottom dwellers used fins to "wadde" (such as the coelacanth). Pelvic and pectoral fins are muscular with extensions of the skeleton. Gave rise to the amphibians.
Trace Fossils
Record activity of organism. Geological records of biological activity. Fossil of a footprint trail burrow or other trace of an animal rather than of the animal itself
What is the evidence that Glaciers were widespread during Late Proterozoic snowball earth?
Reduce CO2 fluxes into the atmosphere, world ices over completely which shuts down weathering and the oceans become anoxic
What are continental red beds and what do they indicate about condition of the atmosphere?
Sandstone and shales of red color. They indicate a transition to a warmer atmosphere. RED COLOR IS CAUSE BY OXIDATION OF IRON ON SURFACE. INDICATES OXYGEN IS NOW PRESENT IN ATMOSPHERE.
What is the relationship between sea level and climate? Why is there a connection?
Sea level rises as glaciers melt. Glaciers are melting due to high CO2 levels in the atmosphere which are caused by Greenhouse gases.
What are stromatolites and how do they form? Why were they important?
Single celled prokaryotes. Formed by malt-like masses of microbes-photosynthetic cyanobacteria
Discuss the benefits of skeletonization.
Storage of mineral nutrients protection from predators movement support increase in size It was an adaptive breakthrough, allowing preferential survival and niche exploration
What is the Greenhouse effect?
The absorption of longwave radiation by greenhouse gases in earth's atmosphere
What is Albedo?
The fraction of solar energy reflected from the eath back into space. (High albedo is found on snow and ice)
What in the relationship of CO2 and global atmospheric temperatures?
The relationship is prevelant in atmospheric temperatures because when rainfall with CO2 falls it weathers the mountain which alters the weather by cooling it. The higher amount of CO2 in the atmosphere heats up the global atmospheric temperature more.
What is the importance of the appearance of burrows? Describe these burrows.
They are trace fossils, and trace fossils tell you about behavior of the organisms. Hints that life is becoming complicated
Why does the fossil record become richer during the Cambrian?
They had shells, there was now something to fossilize
What fish has a wrist?
Tiktaalik
What is the Greenhouse effect?
Trapping of Suns warmth in planets lower atmosphere, land and water absorb radiation, which gets trapped by greenhouse gases- making atmosphere warmer
What are trilobites?
Trilobites were the first recognizable fossil. Most common and diverse invertebrate
What is the duration of the Wilson cycle?
Wilson cycle consists of 400-500 million years
What are Cynodonts?
a carnivorous, mammal like fossil reptile of the late Permian and Triassic periods, with well-developed, specialized teeth
Why did the first amphibians make excursions out of the water and onto land?
food, oxygen, sex
What are Banded Iron Formations, and how were those structures formed?
formations of alternating hematite and jasper (quartz mineral) bands. There are 3 possible mechanisms for formation. Direct oxidation by O2, UV-photo oxidation, and microbial Fe-oxidizing bacteria,
How did coal form? Describe the environment to where coal forests grew. When and where did it form?
formed when organic matter didnt decompose and was buried. Stored carbon
Discuss the relationship between oxygen and carbon dioxide during the Carboniferous Period.
high o2, low co2. very little decomposition in high o2 environment.
Lobefin Fishes
immediate predecessor of tetrapods - One of the most important characteristics of lobe-finned fish is the lobe in their fins. Unlike other fish, sarcopterygian fish has a central appendage in their fins containing many bones and muscles. The fins are very flexible and potentially useful for supporting the body on land, as in lungfish and tetrapods. Additionally, the Sarcopterygii is known for having enamel on the teeth.
What was the cause of the Huronian Glacial event? How was this event different from Snowball Earth?
in increase of photosynthesis which eventually decreased the greenhouse effect. Silicate weathering slowed decreased CO2
In lobefin fishes, when do nostrils appear?
in panderichthys
Agnatha
a superclass of jawless fish in the phylum chordata
What are the benefits of an amniotic egg compared to an amphibian egg?
amniotic egg gives more protection, incubates on land, and baby comes out looking like adult Amphibian eggs need to be in water and young must go through metamorphosis.
Placoderms
jawed fish from the silurian period with absent teeth. The outside shell of its head and neck were made of bone while the remained of its body was cartilage. Slower than sharks Placoderms do not have true teeth
Why did fishes start breathing air?
low oxygen levels in water
How could such a complex structure like an eye evolve?
millions of years of evolution
What is the fate of the gill arches in fishes
move to form our neck, jaw and ear bones
Amino Acids
proteins of life. organic molecules combined in a specific sequence to form a protein
What indicates that free oxygen was present in the Proterozoic atmosphere 1.8 billion years ago?
red beds
What is the relationship between sexual reproduction and evolution?
sexual reproduction varies in a population as well as evolution
Describe the general Carboniferous forest ecology.
super dense, constant warm temps, very humid.
What is the red Queen hypothesis and how does this hypothesis help to explain the importance of sexual reproduction?
the environment is constantly deteriorating making it so that we have to continually evolve just to "keep up". Sexual organisms can evolve faster than asexual organisms because crossing over, random assortment and random gamete fusion introduce new genes, making offspring more variable
Rayfin Fishes
the largest and most successful group of fishes and make up half of all living vertebrates. One the first fish with bone. Small series of bones outward creating a fin.True bone, true teeth fused with jaw bone
Were the first tetrapods good swimmers or good walkers? Explain.
they were good walderlers. They still had many amphibian characteristics, like lateral lines, so early tetrapods lived in the water and hunted on land. The more they developed the more time they spent on land.
When is a fish not a fish but an amphibian?
thin skin covers body • 3-chambered heart • breath with lungs • reproduce in water • legs • tail • ear to hear
How did the retreat of glaciers during the snowball earth influence the development of metazoans?
warming leads to the rapid melting of ice which causes a big increase in evolution. Due to nutrients in the oceans, sharp increases in phosphorus, increase in photosynthesis algae, oxygen and nutrients stimulated evolution of metazoans.
What are some of the characteristics that you share with Tiktaalik?
• neck • shoulder blades
Discuss the transition from Lobefin Fishes to Amphibians. Place the following in correct order of appearance (Acanthostega, Eusthenopteron, Panderichthys, Ichthyostega, and Tiktaalik), and, for each, discuss the characteristics that were important during this transition.
• panderichthys: external nose holes • tiktaalick: first animal with neck and shoulder blade • acanthostega: first with fingers(8) • Ichthyostega: strong pectoral girdle(breast bone). 7 toes • pederes: 5 toes