Lecture 2 Evolution, biosphere, and science (pages 9-16) Life Science I 83.101.102 Dr. Ekaterina (Kate) Vorotnikova Office: 413b E-mail: Ekaterina_Vorotnikova@uml.edu Lecture 2 Evolution, biosphere, and science (pages 9-16)

Mader, Essentials of Biology 2E with CONNECT Plus Access Card Essentials of Biology Second Edition Sylvia S. Mader with McGraw-Hill Connect Biology

Student registration info Course: Life Science 83.101.102  Instructor: Ekaterina Vorotnikova   Section: Spring 2010 mwf 9 am  online registration instructions Go to the following Web address and click the "register now" button: http://connect.mcgraw-hill.com/class/e_vorotnikova_spring_2010_mwf_9_am (http://connect.mcgraw-hill.com/class/e_vorotnikova_spring_2010_mwf_9_am) Web addresses cannot contain spaces. Use lowercase letters or numbers or special characters ( '-' and '_' ) only. This is a unique address for Spring 2010 mwf 9 am

Assignments for a 1/25 week: 1. Lec 1 Assignment 2. Quiz 1 3. Work on LearnSmart study modulus to study chapter 1 until Feb.2 Due on Monday Feb. 1 at 11:00 p.m.

Final grade Grade for exams – 50%; Grade for assignments – 30% (20% for assignments + 10% LearnSmart activity); Grade for quizzes – 20% (100 points max + 5 points for attendance.) Total number of points -105.  

Evolution, the Unifying Concept of Biology Despite diversity, organisms share the same basic characteristics Composed of cells organized in a similar manner Their genes are composed of DNA Carry out the same metabolic reactions to acquire energy This suggests that they are descended from a common ancestor

Classification Taxonomy: Discipline of identifying and classifying organisms according to certain rules Hierarchical levels (taxa) based on hypothesized evolutionary relationships Levels are, from least inclusive to most inclusive: Species, genus, family, order, class, phylum, kingdom, and domain A level (e.g. phylum) includes more species than the level below it (e.g. class), and fewer species than the one above it (e.g. kingdom)

Scientific Names Binomial nomenclature (two-word names)- used to assign each organism with two part name e.g. Homo Sapience Universal Latin-based First word represents genus of organism e.g. Homo Second word is specific epithet of a species within the genus e.g. Sapience Always italicized as a Genus species (Homo sapiens) Genus may be abbreviated e.g. Escherichia coli as E. coli

Taxonomy Leopard: Panthera pardus Jaguar: Panthera onca Tiger: Panthera tigris Lion: Panthera leo Domain: Eukarya Kingdom: Animalia   Phylum: Chordata   Class: Mammalia   Order: Carnivora   Family: Felidae   Genus: Panthera   Species: P. pardus; P. onca; P. tigris; P. leo

Crossota millsae, a brilliant red and purple jellyfish found at a depth of 2000m in the Arctic Ocean The small blue jelly, a type of Narcomedusae, is new to science. Rhacophorus suffry Miniature Muntjac, Muntiacus putaoensis

Biology, 9th ed,Sylvia Mader Domains Chapter 01 Common ancestor Bacteria : Microscopic unicellular prokaryotes Archaea: Bacteria-like unicellular prokaryotes; Extreme aquatic environments Eukarya: Eukaryotes – Familiar organisms I made this figure as a draft. I could replace it by a better one or if you do have a similar figure add it here. A View of Life

PROKARYOTES EUKARYOTES

Prokaryotic cell Eukaryotic cell DNA (no nucleus) Membrane 1-10 µm Figure 1.3 Contrasting the size and complexity of prokaryotic and eukaryotic cells. This figure indicates that the eukaryotic cell is subdivided into functional compartments (organelles) by membranes. Nucleus (contains DNA) 10-100 µm Organelles

Evolution, the Unifying Concept of Biology In 1859, Charles Darwin (12 February 1809 – 19 April 1882) published On the Origin of Species by Means of Natural Selection, presenting a strong, logical explanation of descent with modification, evolution by the mechanism of natural selection. Evolution is descent of species from common ancestors, with genetic modifications that make each species more suited to its environment. Randal Keynes, 62, is the great-great-grandson of Charles Darwin. He is also the author of the book Darwin, His Daughter, and Human Evolution, inspiration for the new film Creation, starring Paul Bettany and Jennifer Connelly. The film opened last Friday and gets a wider release Jan. 29.

Natural Selection A process in which steps 1-3 result in population adapted to the environment (4) The members of a population have heritable variations: differences in their DNA that can be passed from one generation to the next. The population produces more offspring than the resources of an environment can support. The more adapted individuals survive and reproduce to a greater extent than those that lack the adaptations. Across generations, a larger proportion of the population becomes adapted to the environment.

Descent with Modification. The various species of Hawaiian honeycreepers all evolved from one species of finch which originated in North America and arrived in the Hawaiian Islands millions of years ago. They have different bill shapes adapted to different kinds of food: flower nectar, seeds, fruits, insects.. All honeycreepers still share certain characteristics from common finch ancestor – body shape, nesting behavior, etc.

Organization of the Biosphere Population - Members of a species within an area Community - A local collection of interacting populations Ecosystem – A community plus its physical environment How chemicals are cycled and re-used by organisms How energy flows, from photosynthetic plants to top predators

A grassland, terrestrial ecosystem 1. Chemicals cycle through an ecosystem. 2. Energy flows through ecosystem and dissipates as heat. What are two most biologically diverse ecosystems?

Science: A Way of Knowing Biologists Biology is the scientific study of life.

Flow diagram for the scientific method Scientific method begins with observations. May take advantage of knowledge and experiences of other scientists Scientist uses inductive reasoning – uses creative thinking to combine isolated facts into a cohesive whole. Hypothesis – possible explanation for an event Consider only those that can be tested.

Experiments further observations and test hypothesis. Good experimental design, all conditions constant except experimental variable Test group versus control group Data may suggest correlation. Does not necessarily mean causation Scientists are skeptics Conclusion – is the hypothesis supported or not? Experiments and observations must be repeatable.

Scientific theory Ultimate goal of science is to understand the natural world in accepted explanations for how the world works. Cell theory, gene theory Theory of evolution is considered a unifying concept in biology. Some biologists refer to the principle or law of evolution due to over 100 years of support by so many observations and experiments.

Controlled laboratory experiment to test the effectiveness of a medication in humans Controlled study Hypothesis : Antibiotic B is better than Antibiotic A in current use for the treatment of ulcers.

3 experimental groups Reduce possible variances by randomly dividing large group. Control group receives placebo.

The Scientific Method Begins with observation Hypothesis Experimentation (Purpose is to challenge the hypothesis) Often divides subjects into a control group and an experimental group Predicts how groups should differ if hypothesis is valid Results or Data (Observable, objective results from an experiment) The results are analyzed and interpreted Conclusions are what the scientist thinks caused the results

Scientific Theory Scientific Theory: Scientific Principle / Law: Joins together two or more related hypotheses Supported by broad range of observations, experiments, and data Scientific Principle / Law: Widely accepted set of theories No serious challenges to validity

Biodiversity Biodiversity is variation in life on Earth, in a zone of air, land, and water where organisms exist (the number of different species) Abundance of species estimated about 15 million. Fewer than 2 mln. have been identified, named and classified The variability of their genes, and The ecosystems in which they live Extinction is: The death of the last member of a species Estimates of 400 species/day lost worldwide