EOSC 326 Final Exam Study Guide Module C Lesson 10 ...
EOSC 326 Final Exam Study Guide Module C Lesson 10 Learning Objectives 1. Describe why organisms have different potential for preservation; Hard body parts are more likely to be preserved than soft body parts, animals with a skeleton or shell is more likely to be preserved. Animals that stay in one place are more likely to be preserved than mobile animals. And animals that live on soft (muddy) substrates are more likely to be preserved than animals that live on hard (rocky) substrates. 2. Compare and contrast body and trace fossils; Body fossils are preservations of actual animal body parts, whereas trace fossils are tracks and evidence left behind by animals such as footprints, fecal matter, and burrows. 3. Compare and contrast the different methods of fossil preservation; Direct preservation is the fossilization of body parts without any chemical or physical changes, except for the removal of soft tissue. Indirect preservation: 1) Carbonization – Common in fish, insects, and plants. Fossils are preserved as thin films of carbon. First the material is buried, then a chemical reaction occurs where water transforms the material into carbon, finally, hydrogen, oxygen, and nitrogen are driven off as gases. 2) Petrification – Common in bones and some groups of plants and shells. Material is first buried, water percolates through pore spaces and a supersaturated solution of calcium carbonate or silica precipitates minerals in the pore spaces. Spaces get completely filled up and the material becomes a solid rock. 3) Dissolution and replacement – Common in shells and other species like trilobites. Material is buried, original material dissolves and is replaced by sediments or other materials like calcite. 4. Define and identify an external mold, a cast and an internal mold; 1) External mold – Preserves the external features a shell. 2) Internal mold – Preserves the internal features of a shell. 3) Cast – Replica of the original shell. 5. List and define the different modes of life that have been exploited by marine organisms over time. 1) Pelagic organisms – Marine animals that live up in the water column. 1. Nektonic groups can move about freely and are not dependent on currents. Size ranges from microscopic to a few meters long. 2. Planktonic groups are microscopic and float around in the water column. 2) Benthic organisms – Marine animals that live on the ocean floor. 1. Infaunal – Animals that live within the substrate. 1. Burrowers – Animals that burrow into muddy substrates, like clams. 2. Borers – Animals that bore into hard rock substrates, like a boring bivalve. 2. Epifaunal – Animals that live on the substrate. 1. Cementing – Sessile animals, do not move around. 2. Vagrant – Animals that move around on the substrate.
Lesson 11 Learning Objectives 1. Compare and contrast a bioherm and a mound; Bioherms (aka reefs) are the product of organic processes. Organisms that are almost exclusively benthic cementers live in one place for an extended period of time, and produce carbonate structures. Mounds are steep cone-‐like structures or flat lenses of relatively small size. They typically form in quiet water environments, they are made of mud and lack a macroscopic skeletal structure. Many metazoan, algae, and microbial communities have played a crucial role in the formation of mounds in the last 3.5 billion years. 2. List and explain the controls of bioherm growth and development; Reefs are restricted to shallow, clear, tropical waters. The majority of reefs are restricted to the photic zone. Temperature: Ideally between 25-‐29°C, but can grow between 18-‐36°C. Salinity: Ideally between 25-‐35ppt, but will grow between 22-‐40ppt. 3. List and explain the different stages of bioherm succession; Known as the Walker-‐Alberstadt model of reef succession. There are four stages: 1) Stabilization – Skeletal debris from echinoderms or algae move around on the substrate and accumulate into piles. Living organisms such as algae, plants, and some types of echinoderms gather around these piles and stabilize the substrate. Low diversity stage. 2) Colonization – Incoming of reef building organisms. Cementers cement down on the mounds and stabilize the substrate creating patch reefs. Massive and branching growth forms act as framework organisms, these groups stick up into the water column and slow down passing material. 3) Diversification – Reef reaches the water/atmosphere interface. Lateral diversity occurs because conditions differ depending on where you are on the reef. 4) Domination – Very low diversity, reef is dominated by only a few species. Encrusting is a typical growth habit in this stage. Change from diversification to domination is often sudden. 4. Compare and contrast the 4 zones found in a reef during the diversification phase; 1) Lagoon – Calm and quiet, this zone is blocked by the reef from wave action. Substrate contains a high amount of organically produced material, this material shifts easily, not many species colonize this zone. Biota is limited to some pelagic scavengers and some infaunal bivalves and worms. 2) Back reef – Shallow, high light intensity and high temperatures. Conditions tend to be moderately quiet, but during heavy storms, parts of the reef crest can get thrown into the back reef. Organisms in this zone are generally radial symmetric; they tend to be stubby, branching or massive forms that extend above the substrate. Sponges, mollusks, crustaceans and burrowers are common here. 3) Reef crest – Built up to near the water/atmosphere interface and is exposed at low tide. This area has greatest wave action, it is very high energy. Cementing is very important, calcareous algae and encrusting corals dominate this area. 4) Fore reef – Extends from low-‐tide mark into deep waters, slopes downward at a steep angle. Species diversity decreases at greater depths, the top part is a high energy zone and animals
either cement or have arms that protrude into the current. This area is rich in cracks and crevices, it has the highest diversity of all reef zones. 5. List and define the three major roles played by organisms that inhabit modern and fossil bioherms; 1) Framework organisms – Provide the rigid skeletal framework that allows the reef to stand above the substrate. Examples include sponges, archaeocyathids, rudist bivalves, and corals. 2) Cementing organisms – Fill in the spaces between the framework organisms, binding the reef together. Examples include algae, corals, and stromatoporoids. 3) Bioeroding organisms – Bore into the framework organisms of the reef and can take over their skeletons. They destroy the reef. Examples include clionid sponges and boring bivalves. 6. Explain why biodiversity in bioherms is so high. This is because the reef can provide many different environments, which allows different species to inhabit different parts of the reef. As well, many different roles are available which takes many different species to fill. Lesson 12 Learning Objectives 1. List and describe the main morphological features of the four groups of benthic organisms in the Lesson; 1) Stromatolites – Mats of cyanobacteria form on hard substrates, the sticky mat traps sediments and in order to photosynthesize, the cyanobacteria must migrate upwards. This cycle continues and pillar-‐like structures are built. 2) Sponges – Sac-‐shaped, consists of two layers of cells held together by mesoglea. Within the mesoglea is the sponge’s skeleton made up of flexible protein fibers and hard spicules. Sponges have no organs, nervous system, circulatory system, mouth, or anus. Stalk-‐shaped sponges are found in deep waters, broad and flat sponges are found in shallow waters. 3) Archaeocyathids – Consisted of a calcium carbonate skeleton, has an exterior cone and an interior cone. The cones are joined together by vertical cross-‐pieces called septae that extended the length of the structure. The space between the cones is called the intervallum. 4) Stromatoporoids – Modular organisms that grow by secreting calcareous sheets parallel to the substrate. They typically have a calcium carbonate skeleton intersperse with irregular vertical pillars. The surface of the organism contains living tissue, while the lower areas are calcite. They can appear as massive domes, sheets, or sticks. 2. Describe how these 4 groups have contributed to bioherm development; 3. Identify which role(s) each of these groups occupies (framework, cementer, bioeroder) in bioherms; 1) Stromatolites – Very minor component of reefs, they only currently grow in extreme environments (ie. High salinity areas like Hamelin Pool) because grazers of the cyanobacteria like snails usually prevent the growth of stromatolites. 2) Sponges – Framework organisms, because of their skeletal structure and their hard spicules. 3) Archaeocyathids – Framework organisms, they have a calcium carbonate skeletal structure. 4) Stromatoporoids – Dome and stick shaped species served as framework organisms, the sheet shaped species served as cementing organisms. 4. Describe the general principle of surface area to volume changes during an organism's growth and why it can impact efficiency and survival;
As a sponge grows, its surface area increases by a square function whereas its volume increases by a cubic function, meaning the volume increases much faster. This large size makes feeding and breathing less efficient for the animal. 5. List and explain the ways that some corals have adapted to compensate for their surface area to volume problem. To address this problem, as sponges grow, the inner walls become more complex with multiple chambers. There are three grades of sponges based on their size and inner wall complexity, from small to large (simple to complex) they are the asconoid, syconoid, and the leuconoid. Lesson 13 Learning Objectives 1. Describe the basic biology and adaptations of corals; • Exclusively marine carnivores; larvae are mobile but adults are benthic cementers. • Corals are characterized by coral polyps sitting in calcium carbonate cups called corallites. • The body wall is made up of three layers: o Outer cell layer – Contains muscle cells, nerve and sensory cells, and cnidocyte cells. o Inner cell layer – Assimilates food. o Mesoglea – Circulates fluid between outer and inner cell layers. Amoeboid cells are suspended in the mesoglea. • Cnidocyte cells are specialized stinging cells found on the tentacles used to subdue prey. Each cell contains a stinging structure called a nematocyst. • Corallites are the hard parts of corals, they are the cups that coral polyps sit in. They are shaped like an ice cream cone, with vertical partitions inside called septa. Septal grooves and growth lines may be apparent on the outside. The part where the polyp is attached is called the calice. • Corals can be solitary or colonial. Solitary corals are single organisms where only one coral is alive at one time. Colonial corals contain many live corals. • As coral polyps grow, they secrete small curved angled plates called dissepiments along the inside of the corallite, this pushes the coral polyp up to where there is more space. The polyp then secretes a horizontal plate below it for it to sit on called a tabula. • Corals solve the surface area to volume problem by having its internal soft tissues protrude into the cavity creating folds, or by growing septa to push the soft tissues together creating folds. These folds increase the surface area available for digestion. • Growth lines can tells us how fast the Earth was rotating in the past. Ordovician year was 412 days whereas a Devonian year was 400 days. Tidal pull of the moon is slowing Earth’s rotation. 2. Define and describe algal/coral symbiosis; • Zooxanthellae are a type of algae that live in the tissue of coral polyps and other organisms. These algae evolved separately from corals. 3. Compare and contrast the advantages and disadvantages of this symbiosis to both parties (algae and coral); • This is a mutually beneficial relationship for the coral and the zooxanthellae. In producing calcium carbonate for its shell, carbon dioxide is also produced. Zooxanthellae photosynthesize and remove carbon dioxide, this drives more calcium carbonate production. • Corals with zooxanthellae grow up to 3 times faster than corals without zooxanthellae. • A second advantage is the oxygen produced by zooxanthellae, and a third advantage is the organics produced are food for the coral. • Zooxanthellae receive carbon dioxide, a place to live, and protection from the coral. • Disadvantage to the coral is it is restricted to the photic zone where photosynthesis can occur. Disadvantage to the zooxanthellae is it may get eaten by the coral.
4. Compare and contrast the traits and adaptations of the three main groups of corals; 1) Tabulate corals – Very small coral, almost all tabulate corals are colonial. They can contain 100-‐1,000 polyps per coral head. Adjacent polyps may be joined by pores that allow some transport of nutrients. Tabulate corals contain zooxanthellae, they lack septa and have well developed tabulae. They do not have a SA:volume problem. 1. Favosites – Closely packed colonial tabulate coral. Corallites are small. Ranges from Ordovician to Permian. 2. Halysites – Chain corals, corallites are linked together in chains. Spaces in the structure are filled with sediments to strengthen the structure. Ranges from Ordovician to Devonian. 3. Syringopora – Loosely bundled corallites linked together by calcium carbonate rods. Ranges from Silurian to Pennsylvanian. 2) Rugose corals – Wrinkled ridges around the outside of the coral, includes both colonial and solitary forms. Solitary forms have a horn shape, colonial forms have hexagonal corallites. Skeleton is made of calcite and they usually have tabulates. There were a minor component of the reef fauna, it is unclear if they had zooxanthellae. Ranged from Ordovician to Permian. 3) Scleractinian corals – Include both solitary and colonial forms, skeleton is made of aragonite. Tabulates are absent but dissepiments are present in many species. Appeared in middle Triassic to repopulate the vacant niches left by the extinct tabulate and rugose corals. Hermatypic corals are the dominant reef builders, they generally have zooxanthellae. They have a basal plate that separates the polyp from the substrate, allows for better anchorage to the substrate. They can also attach to other corallites for additional stability. Ahermatypic corals are non-‐reef building and can live in very deep waters, and lack zooxanthellae. 5. Use the three types of coral as a first approximation for the age of a rock; Time Period Coral types existent Cenozoic Scleractinian Cretaceous Scleractinian Jurassic Scleractinian Triassic Scleractinian Permian Favosites Rugose Pennsylvanian Favosites Syringopora Rugose Mississippian Favosites Syringopora Rugose Devonian Favosites Halysites Syringopora Rugose Silurian Favosites Halysites Syringopora Rugose (Colonial appeared) Ordovician Favosites Halysites Rugose (Solitary) Cambrian Precambrian 6. List key points in the history of the three main groups of corals (e.g. appearance, morphological trends, etc.). • Tabulate corals were the first corals to appear in the Ordovician. They were major reef components during various times in the Paleozoic. • Rugose corals appeared shortly after Tabulate corals. o Ordovician: Simple walls, septa, and tabulae. o Silurian: Colonial forms appeared, and dissepiments appeared. Few Silurian Rugose corals survived into the Devonian. o Devonian: New Rugose corals appeared in the Middle Devonian, with larger forms and wider dissepiments. End-‐Devonian mass extinction hugely impacted them.
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o Mississippian: New Rugose corals appeared, more complex forms, developed a central axial structure in the corallites that helps strengthen the structure. Scleractinian corals first appeared in the Middle Triassic. o Late Jurassic: Expanded with the radiation with Hermatypic and Ahermatypic groups. o Became more active in Mesozoic and Cenozoic. o Colonial forms are now the major component of reef systems.
Module D Lesson 18 Learning Objectives: 1. Describe what factors control speciation events; Biological factors: Reproductive strategy, mode of life, competition, and predation. Environmental factors: Physical barriers, climatic conditions, stability of climate. 2. Compare and contrast cosmopolitan and endemic species; Cosmopolitan species: Restricted to certain habitats, but are found worldwide in these habitats. Example is the bay mussel. Endemic species: Confined to a particular environment, living in small, restricted ranges. Example are the finches of the Galapagos islands. 3. Discuss why there is a species latitudinal diversity gradient; There is higher species diversity in the tropics, and diversity decreases closer to the Polar Regions. This is seen in terrestrial and marine organisms. Possible factors include: Warmer climate in the tropics, more stable and predictable climate in the tropics, more resources in the tropics, and many species originate in the tropics. 4. Compare and contrast speciation events related to dispersalist and vicariance biogeography. Dispersalist biogeography: 1. Corridors: No barriers to dispersal, an example is the continent of North America between Oregon and New York. 2. Filter bridges: Selective connections between two areas. There are some barriers to dispersal such as oceans, mountains, or certain climatic conditions. Some species are able to disperse while others aren’t. An example is the Isthmus of Panama leading to the Great American Biotic Interchange. 3. Sweepstakes route: These are means of dispersal which are chance happenings. Such as two landmasses separated by a large body of water. An example is the transport of iguanas from South America to the Galapagos islands. Vicariance biogeography: • Once large and continuous species have consequently been instantaneously separated into different groups by plate movements, sea level changes, or the appearance of mountain ranges.
Lesson 19 Learning Objectives: 1. Identify and describe the differences between disjunct and temporal biogeographic patterns; Disjunct Patterns -‐ Derived from communities that are already fossilized. Fossils are transported. -‐ Permits us to piece together the formation of tectonic plates at the time the fauna was fossilized. -‐ Aka “beached Viking funeral ships”. Temporal Patterns -‐ Derived from living communities, living creatures are transported by plate tectonics. -‐ Shows how plate tectonics have created or eliminated geographic barriers leading to speciation, competition, and extinction of fauna. 2. Compare and contrast the six different endemic patterns that can be present in fossil and living biotas and be able to cite details of a specific example for each one; Disjunct Patterns 1. Endemic Center Fragmentation -‐ Rifting or seafloor spreading fragments one endemic zone into multiple zones. 2. Tectonic Suturing -‐ Subduction closes ocean basins, bringing different endemic zones side-‐by-‐side. 3. Boundary Off-‐set -‐ Transform faulting and seafloor spreading that occur across two or more endemic faunas can lead to overlaps of endemic zones. Temporal Patterns 1. Faunal Convergence -‐ Ocean basin closes and fauna on both sides of the basin becomes increasingly similar as it gets easier to travel across. 2. Faunal Divergence -‐ Seafloor spreading or mountain belt formation can divide an existing fauna, fauna on opposite sides become increasingly different as dispersion is made harder. 3. Complementarity -‐ Single tectonic activity causes faunal divergence in one area, and faunal convergence in another. -‐ Good example is the Isthmus of Panama. As the land bridge formed, land animals were able to disperse between North America and South America. But marine animals were no longer able to disperse between the Caribbean and the Pacific. 3. Explain the role of diversity differences in identifying different levels of continental fragmentation. Diversity is a function of latitude (check the course notes for details). When one area has a very different level of diversity from an area which is in close proximity, this is odd. This is what 'diversity differences' means. Different levels of continental fragmentation could be interpreted as how far an area has moved relative to where it is now. A little, or a lot.
Module E Lesson 20 Learning Objectives 1. Define the chordates and vertebrates; • Vertebrates are a subgroup of Chordata, contain a notochord, a stiff rod of cells that runs down the center of the spine. Presence of a definite head, series of stiffened segmented elements (vertebrae). • Chordates have a spine but the spine is not segmented, and do not necessarily have a definite head. 2. Describe examples of the early chordates; • Pikaia – Found in the Burgess Shale in BC. Lived swimming above the ocean floor, presence of tentacles at the head. • Myllokunminga – 30mm long, gill pouches behind poorly developed head, myotomes, narrow dorsal fin. • Haikouichthys – Similar to above, may possess a skull. Earliest fish? 3. Describe the evolution of agnathans and the gnathostomes; • Agnathans – Creatures with no jaw. • Gnathostomes – Creatures with a jaw. 4. Express the significance of the evolution of the lobe finned fish from ray fins; • Ray fins currently dominate the oceans, their evolution often occur in pulses concurrent with sharks, perhaps an evolutionary arms race. • Lobe fins have a slower but more powerful stroke than Ray Fins, and are important in our understanding of the later development of terrestrial vertebrates. • Devonian Lobe Fins are regarded as the ancestors of all terrestrial animals. 5. Detail the development of our understanding of the tetrapods. • Tetrapods all share some common features: o A spine consisting of interlocking spurs; o A pelvis attached to a backbone that supports the weight of the animal o All possess a rib cage to protect the heart and lungs o All breathe air through nostrils o They possess limbs (or used to) that follow a pattern of 1 bone – 2 bones – many bones. • Tetrapods evolved from fish. In Devonian times, rivers were drying up, fish stranded in pools of water had to drag themselves onto land and find deeper waters. This led to the evolution of limbs. • Group of Lobe Fins most closely related to Tetrapods are the Eusthenopteron. Lesson 21 Learning Objectives 1. Describe form and function of Acanthostega and its significance in our understanding of tetrapod evolution; • Mainly aquatic animal, developed limbs in water, limbs could not support weight on land, did not have ankle, front elbow could not bend forward, and had 8 fingers. • Further evolution will lead to development of terrestrial animals.
2. Account for the role that environment had on the evolution of limbs; • Devonian was a world that was wet and lush, 10m canopies developed as forests grew, and swamps developed at the borders of land and water. • Limbs developed because limbs were easier to navigate in swamps than were fins. And swamps were a good place to be in terms of hiding from predators like Hyneria. 3. Place Tiktaalik within the story of the evolution of tetrapods. • Tiktaalik was the transition animal between a fish and a tetrapod. It contained features of both which allowed it to live in the water as well as be able to move onto land. • After Eusthenopteron and before Acanthostega.
Lesson 11 Learning Objectives 1. Compare and contrast a bioherm and a mound; Bioherms (aka reefs) are the product of organic processes. Organisms that are almost exclusively benthic cementers live in one place for an extended period of time, and produce carbonate structures. Mounds are steep cone-‐like structures or flat lenses of relatively small size. They typically form in quiet water environments, they are made of mud and lack a macroscopic skeletal structure. Many metazoan, algae, and microbial communities have played a crucial role in the formation of mounds in the last 3.5 billion years. 2. List and explain the controls of bioherm growth and development; Reefs are restricted to shallow, clear, tropical waters. The majority of reefs are restricted to the photic zone. Temperature: Ideally between 25-‐29°C, but can grow between 18-‐36°C. Salinity: Ideally between 25-‐35ppt, but will grow between 22-‐40ppt. 3. List and explain the different stages of bioherm succession; Known as the Walker-‐Alberstadt model of reef succession. There are four stages: 1) Stabilization – Skeletal debris from echinoderms or algae move around on the substrate and accumulate into piles. Living organisms such as algae, plants, and some types of echinoderms gather around these piles and stabilize the substrate. Low diversity stage. 2) Colonization – Incoming of reef building organisms. Cementers cement down on the mounds and stabilize the substrate creating patch reefs. Massive and branching growth forms act as framework organisms, these groups stick up into the water column and slow down passing material. 3) Diversification – Reef reaches the water/atmosphere interface. Lateral diversity occurs because conditions differ depending on where you are on the reef. 4) Domination – Very low diversity, reef is dominated by only a few species. Encrusting is a typical growth habit in this stage. Change from diversification to domination is often sudden. 4. Compare and contrast the 4 zones found in a reef during the diversification phase; 1) Lagoon – Calm and quiet, this zone is blocked by the reef from wave action. Substrate contains a high amount of organically produced material, this material shifts easily, not many species colonize this zone. Biota is limited to some pelagic scavengers and some infaunal bivalves and worms. 2) Back reef – Shallow, high light intensity and high temperatures. Conditions tend to be moderately quiet, but during heavy storms, parts of the reef crest can get thrown into the back reef. Organisms in this zone are generally radial symmetric; they tend to be stubby, branching or massive forms that extend above the substrate. Sponges, mollusks, crustaceans and burrowers are common here. 3) Reef crest – Built up to near the water/atmosphere interface and is exposed at low tide. This area has greatest wave action, it is very high energy. Cementing is very important, calcareous algae and encrusting corals dominate this area. 4) Fore reef – Extends from low-‐tide mark into deep waters, slopes downward at a steep angle. Species diversity decreases at greater depths, the top part is a high energy zone and animals
either cement or have arms that protrude into the current. This area is rich in cracks and crevices, it has the highest diversity of all reef zones. 5. List and define the three major roles played by organisms that inhabit modern and fossil bioherms; 1) Framework organisms – Provide the rigid skeletal framework that allows the reef to stand above the substrate. Examples include sponges, archaeocyathids, rudist bivalves, and corals. 2) Cementing organisms – Fill in the spaces between the framework organisms, binding the reef together. Examples include algae, corals, and stromatoporoids. 3) Bioeroding organisms – Bore into the framework organisms of the reef and can take over their skeletons. They destroy the reef. Examples include clionid sponges and boring bivalves. 6. Explain why biodiversity in bioherms is so high. This is because the reef can provide many different environments, which allows different species to inhabit different parts of the reef. As well, many different roles are available which takes many different species to fill. Lesson 12 Learning Objectives 1. List and describe the main morphological features of the four groups of benthic organisms in the Lesson; 1) Stromatolites – Mats of cyanobacteria form on hard substrates, the sticky mat traps sediments and in order to photosynthesize, the cyanobacteria must migrate upwards. This cycle continues and pillar-‐like structures are built. 2) Sponges – Sac-‐shaped, consists of two layers of cells held together by mesoglea. Within the mesoglea is the sponge’s skeleton made up of flexible protein fibers and hard spicules. Sponges have no organs, nervous system, circulatory system, mouth, or anus. Stalk-‐shaped sponges are found in deep waters, broad and flat sponges are found in shallow waters. 3) Archaeocyathids – Consisted of a calcium carbonate skeleton, has an exterior cone and an interior cone. The cones are joined together by vertical cross-‐pieces called septae that extended the length of the structure. The space between the cones is called the intervallum. 4) Stromatoporoids – Modular organisms that grow by secreting calcareous sheets parallel to the substrate. They typically have a calcium carbonate skeleton intersperse with irregular vertical pillars. The surface of the organism contains living tissue, while the lower areas are calcite. They can appear as massive domes, sheets, or sticks. 2. Describe how these 4 groups have contributed to bioherm development; 3. Identify which role(s) each of these groups occupies (framework, cementer, bioeroder) in bioherms; 1) Stromatolites – Very minor component of reefs, they only currently grow in extreme environments (ie. High salinity areas like Hamelin Pool) because grazers of the cyanobacteria like snails usually prevent the growth of stromatolites. 2) Sponges – Framework organisms, because of their skeletal structure and their hard spicules. 3) Archaeocyathids – Framework organisms, they have a calcium carbonate skeletal structure. 4) Stromatoporoids – Dome and stick shaped species served as framework organisms, the sheet shaped species served as cementing organisms. 4. Describe the general principle of surface area to volume changes during an organism's growth and why it can impact efficiency and survival;
As a sponge grows, its surface area increases by a square function whereas its volume increases by a cubic function, meaning the volume increases much faster. This large size makes feeding and breathing less efficient for the animal. 5. List and explain the ways that some corals have adapted to compensate for their surface area to volume problem. To address this problem, as sponges grow, the inner walls become more complex with multiple chambers. There are three grades of sponges based on their size and inner wall complexity, from small to large (simple to complex) they are the asconoid, syconoid, and the leuconoid. Lesson 13 Learning Objectives 1. Describe the basic biology and adaptations of corals; • Exclusively marine carnivores; larvae are mobile but adults are benthic cementers. • Corals are characterized by coral polyps sitting in calcium carbonate cups called corallites. • The body wall is made up of three layers: o Outer cell layer – Contains muscle cells, nerve and sensory cells, and cnidocyte cells. o Inner cell layer – Assimilates food. o Mesoglea – Circulates fluid between outer and inner cell layers. Amoeboid cells are suspended in the mesoglea. • Cnidocyte cells are specialized stinging cells found on the tentacles used to subdue prey. Each cell contains a stinging structure called a nematocyst. • Corallites are the hard parts of corals, they are the cups that coral polyps sit in. They are shaped like an ice cream cone, with vertical partitions inside called septa. Septal grooves and growth lines may be apparent on the outside. The part where the polyp is attached is called the calice. • Corals can be solitary or colonial. Solitary corals are single organisms where only one coral is alive at one time. Colonial corals contain many live corals. • As coral polyps grow, they secrete small curved angled plates called dissepiments along the inside of the corallite, this pushes the coral polyp up to where there is more space. The polyp then secretes a horizontal plate below it for it to sit on called a tabula. • Corals solve the surface area to volume problem by having its internal soft tissues protrude into the cavity creating folds, or by growing septa to push the soft tissues together creating folds. These folds increase the surface area available for digestion. • Growth lines can tells us how fast the Earth was rotating in the past. Ordovician year was 412 days whereas a Devonian year was 400 days. Tidal pull of the moon is slowing Earth’s rotation. 2. Define and describe algal/coral symbiosis; • Zooxanthellae are a type of algae that live in the tissue of coral polyps and other organisms. These algae evolved separately from corals. 3. Compare and contrast the advantages and disadvantages of this symbiosis to both parties (algae and coral); • This is a mutually beneficial relationship for the coral and the zooxanthellae. In producing calcium carbonate for its shell, carbon dioxide is also produced. Zooxanthellae photosynthesize and remove carbon dioxide, this drives more calcium carbonate production. • Corals with zooxanthellae grow up to 3 times faster than corals without zooxanthellae. • A second advantage is the oxygen produced by zooxanthellae, and a third advantage is the organics produced are food for the coral. • Zooxanthellae receive carbon dioxide, a place to live, and protection from the coral. • Disadvantage to the coral is it is restricted to the photic zone where photosynthesis can occur. Disadvantage to the zooxanthellae is it may get eaten by the coral.
4. Compare and contrast the traits and adaptations of the three main groups of corals; 1) Tabulate corals – Very small coral, almost all tabulate corals are colonial. They can contain 100-‐1,000 polyps per coral head. Adjacent polyps may be joined by pores that allow some transport of nutrients. Tabulate corals contain zooxanthellae, they lack septa and have well developed tabulae. They do not have a SA:volume problem. 1. Favosites – Closely packed colonial tabulate coral. Corallites are small. Ranges from Ordovician to Permian. 2. Halysites – Chain corals, corallites are linked together in chains. Spaces in the structure are filled with sediments to strengthen the structure. Ranges from Ordovician to Devonian. 3. Syringopora – Loosely bundled corallites linked together by calcium carbonate rods. Ranges from Silurian to Pennsylvanian. 2) Rugose corals – Wrinkled ridges around the outside of the coral, includes both colonial and solitary forms. Solitary forms have a horn shape, colonial forms have hexagonal corallites. Skeleton is made of calcite and they usually have tabulates. There were a minor component of the reef fauna, it is unclear if they had zooxanthellae. Ranged from Ordovician to Permian. 3) Scleractinian corals – Include both solitary and colonial forms, skeleton is made of aragonite. Tabulates are absent but dissepiments are present in many species. Appeared in middle Triassic to repopulate the vacant niches left by the extinct tabulate and rugose corals. Hermatypic corals are the dominant reef builders, they generally have zooxanthellae. They have a basal plate that separates the polyp from the substrate, allows for better anchorage to the substrate. They can also attach to other corallites for additional stability. Ahermatypic corals are non-‐reef building and can live in very deep waters, and lack zooxanthellae. 5. Use the three types of coral as a first approximation for the age of a rock; Time Period Coral types existent Cenozoic Scleractinian Cretaceous Scleractinian Jurassic Scleractinian Triassic Scleractinian Permian Favosites Rugose Pennsylvanian Favosites Syringopora Rugose Mississippian Favosites Syringopora Rugose Devonian Favosites Halysites Syringopora Rugose Silurian Favosites Halysites Syringopora Rugose (Colonial appeared) Ordovician Favosites Halysites Rugose (Solitary) Cambrian Precambrian 6. List key points in the history of the three main groups of corals (e.g. appearance, morphological trends, etc.). • Tabulate corals were the first corals to appear in the Ordovician. They were major reef components during various times in the Paleozoic. • Rugose corals appeared shortly after Tabulate corals. o Ordovician: Simple walls, septa, and tabulae. o Silurian: Colonial forms appeared, and dissepiments appeared. Few Silurian Rugose corals survived into the Devonian. o Devonian: New Rugose corals appeared in the Middle Devonian, with larger forms and wider dissepiments. End-‐Devonian mass extinction hugely impacted them.
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o Mississippian: New Rugose corals appeared, more complex forms, developed a central axial structure in the corallites that helps strengthen the structure. Scleractinian corals first appeared in the Middle Triassic. o Late Jurassic: Expanded with the radiation with Hermatypic and Ahermatypic groups. o Became more active in Mesozoic and Cenozoic. o Colonial forms are now the major component of reef systems.
Module D Lesson 18 Learning Objectives: 1. Describe what factors control speciation events; Biological factors: Reproductive strategy, mode of life, competition, and predation. Environmental factors: Physical barriers, climatic conditions, stability of climate. 2. Compare and contrast cosmopolitan and endemic species; Cosmopolitan species: Restricted to certain habitats, but are found worldwide in these habitats. Example is the bay mussel. Endemic species: Confined to a particular environment, living in small, restricted ranges. Example are the finches of the Galapagos islands. 3. Discuss why there is a species latitudinal diversity gradient; There is higher species diversity in the tropics, and diversity decreases closer to the Polar Regions. This is seen in terrestrial and marine organisms. Possible factors include: Warmer climate in the tropics, more stable and predictable climate in the tropics, more resources in the tropics, and many species originate in the tropics. 4. Compare and contrast speciation events related to dispersalist and vicariance biogeography. Dispersalist biogeography: 1. Corridors: No barriers to dispersal, an example is the continent of North America between Oregon and New York. 2. Filter bridges: Selective connections between two areas. There are some barriers to dispersal such as oceans, mountains, or certain climatic conditions. Some species are able to disperse while others aren’t. An example is the Isthmus of Panama leading to the Great American Biotic Interchange. 3. Sweepstakes route: These are means of dispersal which are chance happenings. Such as two landmasses separated by a large body of water. An example is the transport of iguanas from South America to the Galapagos islands. Vicariance biogeography: • Once large and continuous species have consequently been instantaneously separated into different groups by plate movements, sea level changes, or the appearance of mountain ranges.
Lesson 19 Learning Objectives: 1. Identify and describe the differences between disjunct and temporal biogeographic patterns; Disjunct Patterns -‐ Derived from communities that are already fossilized. Fossils are transported. -‐ Permits us to piece together the formation of tectonic plates at the time the fauna was fossilized. -‐ Aka “beached Viking funeral ships”. Temporal Patterns -‐ Derived from living communities, living creatures are transported by plate tectonics. -‐ Shows how plate tectonics have created or eliminated geographic barriers leading to speciation, competition, and extinction of fauna. 2. Compare and contrast the six different endemic patterns that can be present in fossil and living biotas and be able to cite details of a specific example for each one; Disjunct Patterns 1. Endemic Center Fragmentation -‐ Rifting or seafloor spreading fragments one endemic zone into multiple zones. 2. Tectonic Suturing -‐ Subduction closes ocean basins, bringing different endemic zones side-‐by-‐side. 3. Boundary Off-‐set -‐ Transform faulting and seafloor spreading that occur across two or more endemic faunas can lead to overlaps of endemic zones. Temporal Patterns 1. Faunal Convergence -‐ Ocean basin closes and fauna on both sides of the basin becomes increasingly similar as it gets easier to travel across. 2. Faunal Divergence -‐ Seafloor spreading or mountain belt formation can divide an existing fauna, fauna on opposite sides become increasingly different as dispersion is made harder. 3. Complementarity -‐ Single tectonic activity causes faunal divergence in one area, and faunal convergence in another. -‐ Good example is the Isthmus of Panama. As the land bridge formed, land animals were able to disperse between North America and South America. But marine animals were no longer able to disperse between the Caribbean and the Pacific. 3. Explain the role of diversity differences in identifying different levels of continental fragmentation. Diversity is a function of latitude (check the course notes for details). When one area has a very different level of diversity from an area which is in close proximity, this is odd. This is what 'diversity differences' means. Different levels of continental fragmentation could be interpreted as how far an area has moved relative to where it is now. A little, or a lot.
Module E Lesson 20 Learning Objectives 1. Define the chordates and vertebrates; • Vertebrates are a subgroup of Chordata, contain a notochord, a stiff rod of cells that runs down the center of the spine. Presence of a definite head, series of stiffened segmented elements (vertebrae). • Chordates have a spine but the spine is not segmented, and do not necessarily have a definite head. 2. Describe examples of the early chordates; • Pikaia – Found in the Burgess Shale in BC. Lived swimming above the ocean floor, presence of tentacles at the head. • Myllokunminga – 30mm long, gill pouches behind poorly developed head, myotomes, narrow dorsal fin. • Haikouichthys – Similar to above, may possess a skull. Earliest fish? 3. Describe the evolution of agnathans and the gnathostomes; • Agnathans – Creatures with no jaw. • Gnathostomes – Creatures with a jaw. 4. Express the significance of the evolution of the lobe finned fish from ray fins; • Ray fins currently dominate the oceans, their evolution often occur in pulses concurrent with sharks, perhaps an evolutionary arms race. • Lobe fins have a slower but more powerful stroke than Ray Fins, and are important in our understanding of the later development of terrestrial vertebrates. • Devonian Lobe Fins are regarded as the ancestors of all terrestrial animals. 5. Detail the development of our understanding of the tetrapods. • Tetrapods all share some common features: o A spine consisting of interlocking spurs; o A pelvis attached to a backbone that supports the weight of the animal o All possess a rib cage to protect the heart and lungs o All breathe air through nostrils o They possess limbs (or used to) that follow a pattern of 1 bone – 2 bones – many bones. • Tetrapods evolved from fish. In Devonian times, rivers were drying up, fish stranded in pools of water had to drag themselves onto land and find deeper waters. This led to the evolution of limbs. • Group of Lobe Fins most closely related to Tetrapods are the Eusthenopteron. Lesson 21 Learning Objectives 1. Describe form and function of Acanthostega and its significance in our understanding of tetrapod evolution; • Mainly aquatic animal, developed limbs in water, limbs could not support weight on land, did not have ankle, front elbow could not bend forward, and had 8 fingers. • Further evolution will lead to development of terrestrial animals.
2. Account for the role that environment had on the evolution of limbs; • Devonian was a world that was wet and lush, 10m canopies developed as forests grew, and swamps developed at the borders of land and water. • Limbs developed because limbs were easier to navigate in swamps than were fins. And swamps were a good place to be in terms of hiding from predators like Hyneria. 3. Place Tiktaalik within the story of the evolution of tetrapods. • Tiktaalik was the transition animal between a fish and a tetrapod. It contained features of both which allowed it to live in the water as well as be able to move onto land. • After Eusthenopteron and before Acanthostega.
