Week 11 Animal Classification Domain Eukarya Kingdom Animalia Multi cellular organisms with tissues except sponges Animals are heterotrophic and able to move Classification True Tissue Symmetry o All animals besides sponges have true tissues o Radial multiple planes divide the organisms into mirror images Cnidarians o Bilateral only one plane divides the organism into mirror images everything else besides sponges which have no symmetry Gut Development o Protostome mouth first gut develops front to back Anthropods Roundworms Molluscs Annelids and Flatworms o Deuterostome mouth second gut develops back to front Chordates and Echinoderms Molting shedding an exoskeleton and replacing it with a larger one at regular intervals o Anthropods and Roundworms molt o Molluscs Annelids and Flatworms do not molt In Sum Chordates All features form in embryos but may no persist in adulthood Notochord rod of tissue that extends from heads to tail stiffens when the muscles contract during locomotion primitive chordates keep the notochord for life Dorsal Hollow Nerve cord forms the central nervous system in vertebrates Pharyngeal Gill Slits earliest chordates were aquatic but now all chordates retain gill slits in the embryo Post Anal Tail for some chordates this is only present in the embryonic form o For example the hagfish has a skull of cartilage lacks jaws and vertebrae and the notochord is retained as a flexible rob of cartilage Vertebrae Chordates Key Features The vertebra protects the nerve cord and places for muscle attachment Made way for adaptive radiation organisms diversify into new forms of fast moving animals in the sea Jaws are hinged bones that frame the mouth arose from gill arches the evolution of jaws selected for new defenses in prey Paired fins allow fish to swim fast and straight with great maneuverability Jaws and paired fins arose around the same time which created a great selective pressure on predators and prey for fast maneuverability and good sensory system Lampreys Fishes without jaws or paired fins a tail fin propels them through water Parasitic feed by attaching mouth to fish and sucking out the fish s liquids with a scraping tongue only 1 7 fish survive a lamprey attack Invasive species to the Great Lakes Skeleton of cartilage Fishes Three types are cartilaginous ray finned and lobe finned The developments of jaws and fins allowed for fish diversity Transition from Water to Land 3 main obstacles respiration gravity and egg desiccation drying out Predatory fish living in shallow water evolved major innovations which allowed hem to move to land Respiration Problem Gravity Problem o Aquatic animals used gills o To breath on land lungs evolved from the swim bladder found in ray finned fish o Transition to land required structural support to resist gravity s pull o Limbs evolved from jointed fins found in lobe finned fishes and vertebrae modified to transmit body weight Egg Desiccation Problem o Eggs once laid in water needed to be laid on land o Amniotic eggs were created with a water proof eggshell to prevent drying out before the egg was ready to hatch Limbs lungs and modified vertebrae evolved from fish to make amphibians Amphibians First terrestrial vertebrates Double life because they are born and young in the water and move to land for adulthood Eggs are non amniotic Reptiles Amniotic eggs paired kidneys scaly skin ectothermic body temp is controlled by outside conditions Birds are just reptiles that evolved to have feathers feathers evolved before birds and probably had nothing to do with flight instead they were fore courtship and insulation Reptiles and birds evolved to being mammals with hair long legs and mammary glands Mammals Split from reptiles early mammals ate insects Endothermic have hair and produce milk for their young Adaptations o Hair for insulation o Mammary glands for nursing the young o Long vertical legs allowed for faster running and catching prey Groups of Mammals echidnas o Monotremes females lay eggs don t have nipples 5 species platypus and o Marsupials females give birth after a short period of development most species have a pouch for further development of the young about 300 species including kangaroos o Placental females have a placenta that give oxygen and nutrients to the embryo about 4 500 species currently Week 12 Ecology the study of interactions between organisms and their environment Population Ecology study of populations in relation to their environment The exponential model of growth creates a J shaped curve which characterizes some rebounding populations elephant populations grew exponentially after hunting was banned The logistical model created an S shaped curve once the organism reaches carrying capacity Populations can cycle based on predator prey relations Human Population Growth Human population grew slowly until 1650 when it started increasing greatly The global population is now more than 7 billion Age structure diagrams can predict population growth as well as illuminate social conditions the carrying capacity for humans is 10 billion but we can increase the carry capacity by expanding to new habitats increasing agricultural productivity and finding new way to live at higher densities Community Ecology o Populations interact to form communities interspecific interactions o Since these interaction affect the survival and reproduction they can be either negative positive or neutral 0 o Species compete for a resource in short supply o Strong competition can lead to local elimination of the competing specie Competition Predation o Predator prey interaction o Feeding adaptations of predators are claws fangs poison and stingers o Predation exerts strong selective pressure on prey which adapts defenses of camouflage cryptic coloration aposematic hiding forming herds alarm calls or mimicry Symbiosis species living in direct and intimate contact with each other o Parasitism the parasite derives nourishment from the host which is harmed in the process parasites can change the behavior of the host to benefit itself o Mutualism benefits both species the ant acacia tree o Commensalism 0 one specie is benefited and the other is indifferent birds and water buffalos o Facilitation or 0 one species has positive effects on another species without direct contact the plant Juncus makes the soil more hospitable for other plants to grow Week 13 Community Ecology Succession gradual change in species composition over time o Primary