Lesson 7

• Evolution


  Descent with modification, a process in which species change and give rise to new species over many generations
• Evolutionary history of life

  • Forms a branching tree with many levels, in which all species can be traced back to an ancient common ancestor
• Protein Sequencing


  A technique to find out amino acid sequences in protein
• Homologous features


  If two or more species share a unique physical feature, such as a complex bone structure or a body plan, they may all have inherited this feature from a common ancestor
• Analogous features


  Physical similarities that evolved independently in different organisms because the organisms lived in similar environments or experienced similar selective pressures
• Convergent evolution


  The process where analogous features evolve independently in different organisms
• Biologists don't conclude how species are related based on any single feature they think is homologous. Instead, they study a large collection of features (often, both physical features and DNA sequences) and conclude relatedness based on these features as a group.
• Molecular biology


  Similarities between biological molecules can reflect shared evolutionary ancestry
• DNA


  The molecule that carries genetic information for the development and functioning of an organism
• RNA


  The molecule that is present in the majority of living organisms and viruses, made up of nucleotides
• Transcription and translation


  Processes that take the information in DNA and use it to produce proteins
• Biogeography


  The geographic distribution of organisms on Earth follows patterns that are best explained by evolution, in combination with the movement of tectonic plates over geological time
• Fossil record


  Preserved remains of previously living organisms or their traces, dating from the distant past