What do we call this↓? Scientific Name Lumbriculus variegatus The California Blackworm What do we call this↑? Common Name Lumbriculus variegatus Scientific classification Kingdom: Animalia Phylum: Annelida Class: Clitellata Subclass: Oligochaeta What is this called? Order: Lumbriculida Family: Lumbriculidae Genus: Lumbriculus Species: L. variegatus Specific Epithet From: http://en.wikipedia.org/wiki/Lumbriculus_variegatus How do we know that the CA Blackworm is alive? • It has all of the CHARACTERISTICS OF LIFE • What are they? • Made of Cells, Taken as a group change over time (Evolution), Respond to their environment, contain the universal genetic code (DNA), Obtain and use materials and energy, Grow and Develop, Reproduce, Maintain a stable internal environment (Homeostasis) California Blackworm • • • • • • Made of Cells A multicellular organism Cells form __________ Tissues Tissues form ___________ Organs Organs form __________________ Organ Systems Organ Systems for the Multicellular ___________________ Organism California Blackworm • Taken as a group, change over time. What does this mean? • They have evolved. • They are adapted to their environment. • They have adaptations that allow them to live in shallow freshwater. Name some of their adaptations. How could this be Behavior / an adaptation for Appearance survival? • Some worms tend to form clumps and tangled masses • They have transparent skin. Worms in the middle are protected from ultraviolet rays that may reach them • Those in the middle are protected from predators, won’t easily become fish food! How could this be Behavior / an adaptation for Appearance survival? • Protective coloration • They look like the color of their natural environment, mud, making them less easily visible to predators. How could this be Behavior / an adaptation for Appearance survival? • Some • The anterior end feeds while the posterior is up higher in position the water. There is more themselves oxygen higher up in the with their water. Worms get oxygen by posterior up diffusion through their skin. and their • Posterior has light receptors anterior down which alert the worm to changes in light which may signal the presences of a predator How could this be Behavior / an adaptation for Appearance survival? • They move like a corkscrew when you touch one of their ends. • If the anterior is touched, the worm first turns before corkscrewing away. This allows it to protect its anterior end. • When touched on the posterior, the worm moves quickly from danger in a corkscrew motion. Evolution In 1859 the English naturalist Charles Darwin published The Origin of Species. The book contained two major arguments: 1. He said that all living things on earth today are the descendants — with modifications — of earlier species. 2. Natural selection is the mechanism that explains how evolution takes place. Evolution involves two interrelated phenomena: adaptation Over the course of time, species modify their phenotypes in ways that permit them to succeed in their environment. speciation Over the course of time, the number of species multiplies; that is, a single species can give rise to two or more descendant species. Darwin maintained that all species are related; that is, any two species on earth today have shared a common ancestor at some point in their history. From: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/E/Evolution.html http://www.pbs.org/wgbh/evolution/educato rs/teachstuds/svideos.html http://www.ucmp.berkeley.edu/education/e xplorations/tours/Trex/index.html What Did T. rex Taste Like? is an introduction to cladistics, the most commonly used method of classification today. Cladistics organizes living things by common ancestry and evolutionary relationships, enabling us to better understand life's present diversity and evolutionary history. Like other methods of classification, cladistics makes use of the observable features of organisms. Cladistics also allows us to examine the ways in which features change within groups, and to observe patterns of origin and diversification over time. Unlike any other method of classification, cladistics is a powerful predictive tool, allowing us to propose hypotheses about the relationships between organisms. This module presents a simplified version of the process used to generate cladistic analyses and demonstrates its predictive power. Typically dozens or even hundreds of features are examined before a cladogram is produced. Although in this module only structural features are used, true cladistic analyses also use biochemical, genetic and even behavioral features. California Blackworms • Have the universal genetic code • DNA makes _______ RNA which makes a Polypeptide which forms a _________ Protein ____________ • What is a segment of DNA that codes for Gene polypeptide called? _____________ chromosomes • Where do we find genes? On ______________ • What does chromosome mean? • Colored Body California Blackworms • Respond to their environment • How do they they respond when you touch their anterior? Turn around • How do they respond when you touch their posterior? Corkscrew away California Blackworms • Obtain and use materials and energy. Explain. • They are Heterotrophs • Ingest, Digest, Absorb nutrients which move by diffusion through their bloodstream to their cells so that the cells Cellular Respiration to make ATP can do __________________________ Energy… You get it from Cellular Respiration. California Blackworms • Grow and Develop. Explain. • Get bigger and change California Blackworms • Reproduce. Explain. • Asexually by fragmentation California Blackworms • Maintain a stable internal environment. Explain. • Homeostasis – i.e. These organisms must regulate water, salts, glucose, etc.in their bodies. Which end is this? Anterior Which end is this? What is happening here? Damaged worm will fragment Posterior Why is this end this light color? The worm has regenerated posterior segments Image From: http://www.raazebaghaa.com/showthread.php?p=1362 Blood flows from posterior to anterior on the dorsal side. Enlarged California Blackworm anterior is darker and thicker Enlarged California Blackworm posterior is lighter and thinner Enlarged California Blackworm Where is the pulse faster? Posterior, Why? Because that is where it originates! Enlarged California Blackworm Don’t Forget to Study!
