The Study of Life

• Formerly called blue-green algae, these cyanobacteria are some of Earth's oldest life forms
• Stromatolites along the shores of Lake Thetis in Western Australia are ancient structures formed by the layering of cyanobacteria in shallow waters
• Biology


  The study of living organisms and their interactions with one another and their environments
• Biology is a very broad discipline because the scope of biology is vast.
• Biologists may study


  • Microscopic or submicroscopic view of a cell
  • Ecosystems and the whole living planet
• Many researchers are committed to finding ways to protect the planet, solve environmental issues, and reduce the effects of climate change
• Science


  Knowledge that covers general truths or the operation of general laws, especially when acquired and tested by the scientific method
• Scientific method


  A method of research with defined steps that include experiments and careful observation
• Hypothesis


  A suggested explanation for an event, which can be tested
• Theory


  A tested and confirmed explanation for observations or phenomena
• Science may be better defined as fields of study that attempt to comprehend the nature of the universe
• Natural sciences (alternative definition)

  • Life sciences (biology)
  • Physical sciences (astronomy, geology, physics, chemistry)
• Natural sciences are sometimes referred to as "hard science" because they rely on the use of quantitative data
• Branches of biology


  • Cell biology
  • Anatomy
  • Physiology
  • Botany
  • Zoology
• Inductive reasoning


  A form of logical thinking that uses related observations to arrive at a general conclusion
• Deductive reasoning


  A form of logical thinking that uses a general principle or law to forecast specific results
• Descriptive (or discovery) science, which is usually inductive, aims to observe, explore, and discover
• Hypothesis-based science, which is usually deductive, begins with a specific question or problem and a potential answer or solution that can be tested
• The scientific method was first documented by England's Sir Francis Bacon
• The scientific method


  1. Observation

  2. Question

  3. Hypothesis (suggested explanation)

  4. Prediction

  5. Experiment

  6. Result analysis
• A valid hypothesis must be testable and falsifiable
• Rejecting one hypothesis does not determine whether or not other hypotheses can be accepted, it simply eliminates one hypothesis that is not valid
• Inductive and deductive reasoning are often used in tandem to advance scientific knowledge
• My coffeemaker works
• Inductive reasoning


  Drawing a general conclusion from a number of observations
• Deductive reasoning


  Predicting specific results from a general premise
• Inductive reasoning example


  • Observations: 1) Members of a species are not all the same, 2) Individuals compete for resources, 3) Species are generally adapted to their environment. Conclusion: Individuals most adapted to their environment are more likely to survive and pass their traits on to the next generation.
• Deductive reasoning example


  • Premise: Individuals most adapted to their environment are more likely to survive and pass their traits on to the next generation. Prediction: If global climate change causes the temperature in an ecosystem to increase, those individuals better adapted to a warmer climate will outcompete those that are not.
• Examples of reasoning


  • All flying birds and insects have wings, birds and insects flap their wings as they move through the air, therefore wings enable flight
  • Insects generally survive mild winters better than harsh ones, therefore insect pests will become more problematic if global temperatures increase
  • Chromosomes, the carriers of DNA, separate into daughter cells during cell division, therefore DNA is the genetic material
  • Animals as diverse as humans, insects, and wolves all exhibit social behavior, therefore social behavior must have an evolutionary advantage
• The scientific method may seem too rigid and structured, but there is flexibility
• Scientific reasoning is more complex than the scientific method alone suggests
• The scientific method can be applied to solving problems that aren't necessarily scientific in nature
• Basic science


  Seeks to expand knowledge regardless of the short-term application of that knowledge
• Applied science


  Aims to use science to solve real-world problems
• Examples of applied science

  • Improving crop yield, finding a cure for a disease, saving animals threatened by a natural disaster
• Basic knowledge has resulted in many remarkable applications of great value
• Applied science relies on the results generated through basic science
• Few solutions would be found without the help of the wide knowledge foundation generated through basic science
• Examples of how basic and applied science work together

  • Discovery of DNA structure led to understanding of molecular mechanisms governing DNA replication, enabling development of techniques to identify genetic diseases, pinpoint crime scene individuals, and determine paternity
  • The Human Genome Project relied on basic research with simple organisms and the human genome, with the goal of using the data for applied research to seek cures and early diagnoses for genetically related diseases
• Some discoveries are made by serendipity, a fortunate accident or lucky surprise