The Role of Natural Selection & Evolution in Biology: Overview of Darwin's Theory, Exercises of Biology

Download The Role of Natural Selection & Evolution in Biology: Overview of Darwin's Theory and more Exercises Biology in PDF only on Docsity! Evolution – How Change Occurs Name: ____________________________________ Some Things to Keep in Mind What is SCIENCE? A process that seeks to find ____________________________ for observations of the ________________________________ What are the rules of science? One rule is that we rely on ____________________________________________________ to explain phenomena we see. Science is ___________________________________  Scientific questions must be TESTABLE and that means that you can make observations either through experimentation or some other means to test whether a hypothesis is wrong. Another rule is that science can be _______________________________________!  Scientific process is designed to correct itself  If a scientific idea is found to be wrong or partially wrong, the whole point of science is for evidence to be presented to fix the idea  If evidence arises to disprove an idea, the idea will be either ___________________ to fit the new evidence or it will be ________________________ all together. It’s called the THEORY of Evolution – what does this mean?? THEORY vs. HYPOTHESIS What’s a hypothesis? A ________________ (usually educated) about an explanation for an observation  NOT ____________________- a lot  NOT _____________________ by evidence, or perhaps supported by only a few experiments  Often in everyday usage, people say “I have a theory about…” when what they really mean is “hypothesis”. What is a Theory? An idea that  Explains a _________ of observable phenomena  Has been supported by a _________________ body of evidence  Has been studied by _____________________ people and ______________________ a LOT.  In science it explains something about how things happen in the natural world • Fact: An apple falls from a tree • Theory: Newton’s theory of gravitation explains WHY the apple falls from the tree. So, What is Evolution? Evolution = the __________________ of organisms on Earth have __________________________________________________________________ Natural Selection is the ________________________ of HOW organisms have changed. Where did the idea of evolution come from? ____________from Charles __________________________ The idea of Evolution has been around for a very long time  ______________________________ (Greeks) Darwin is just the one who gave us a __________________________ by which evolution could occur Docsity.com Who is Charles Darwin? British Born _____________________ Tried many careers  Minister  Doctor Became ship’s naturalist aboard the __________________________  _______________-____________________  Focus of ship was to map coast of _______________________ and collect specimens of life forms there HMS Beagle It was Darwin’s job to hike the coast of ______________________________ wherever the Beagle stopped. He made notes describing land forms, etc. He collected LOTS of specimens  Both _________________ specimens and ___________________________  Many never before seen by Europeans Galapagos Islands Of particular interest to Darwin were the plants and animals he found on the __________________________________________ He noticed that the forms of plants and animals on these islands were often ___________________ to those on ____________________ S. America, but __________________________ to be adapted to the various different island habitats on which they lived.  Why are they ____________________________ to _______________________________ organisms??  Why _____________ more similar to other island species that live in similar habitats? Example – ___________________________________ Darwin found several different species of finch on the Galapagos Islands Each species was specifically ___________________ to __________ in the particular habitat in which it lived Each was at least somewhat __________________________ to the others on different islands AND to a finch commonly found on the S. American __________________________ Why? Darwin suggested that the solution to this puzzle that made the most sense was that the original mainland ancestor ______________________ one of the islands many years ago It’s _________________________ slowly became _____________________ to the various __________________ sources available on the many different island habitats Darwin’s Book After many years of pouring over his notes and specimens, Darwin finally published his ideas in a book Title: ____________________________________________________ Date published: _______________________  His book was controversial upon its release, as it remains controversial within some groups today. Despite the any controversy, Darwin’s ideas are the centerpiece upon which all of biology is based.  His ideas are ___________ controversial among ____________________________. Docsity.com Some Terms… __________________________________  All the genes within a population of organisms Relative Frequency - The number of times one allele appears in the gene pool as compared to some other allele • Example:  White allele originally appeared _____________% of the time in the moth population.  Black allele only _______% of the time. If the relative frequency of the alleles in a population change over time, then _________________________ change is occurring What constitutes an Evolutionary Change? Evolutionary change involves change in the _____________________________ of certain ____________________________ in the _______________________________.  _____________________________________________________________________ Species and Evolutionary Change What exactly is a species?  Species – A group of similar-looking, though not identical organisms that breed with one another and produce _____________________offspring in the ____________________ environment (not the zoo). Because members of a species (population) can breed with each other, they share a ________________________________________________. Because of that, when a genetic change occurs in an individual, it can ________________________________through the population as that individual and its offspring mate with other individuals. IF that gene INCREASES _______________________________, it will eventually be found in _________________________ individuals in the population (species?) Speciation When ______________ species evolve from _____________ ones How Does Speciation Occur? members of a population must get ______________________________ If the members are separated such that they cannot _______________________, they are in ___________________________________________ If you have two distinct populations that can’t interbreed (can’t share genes) then natural selection can work _____________________________________ on each group  Perhaps their _____________________________________ are different, etc. Because their gene pools are _______________________, adaptations that appear in one group are ________________________ passed onto the other.  THEN ________________ DISTINCT SPECIES MAY DEVELOP over ________________________. How can a population get separated? (reproductive isolation) ______________________________________________ Barrier Differences in ___________________________ may arise, fertile periods, etc. Once separation occurs, natural selection usually ______________________________between pops. Pops. become adapted to __________________________________________, separate gene pools become _______________________________________. Docsity.com Speciation If the populations remain separated for a long time, their gene pools become so different that their reproductive isolation becomes ______________________________. They are now not just separate populations, but separate species. Darwin’s Finches Adaptive Radiation _____________species gives rise to _________________ species Convergent Evolution Organisms that are ___________ closely related share ________________ physical adaptations because of the __________________________________________they occupy Analogous Structures Structures that are ____________________ in appearance and function, but do _________________________ share a ______________________________________ Bird wing and butterfly wing Gradualism Says evolutionary change occurs _________________________/gradually Darwin’s original idea Modifications to Darwin’s idea of Gradualism Environmental change can cause evolution to go __________________ More evolutionary change after a ________________________________  Lots of habitat, niches to fill ___________________________________  A more modern modification of Darwin’s original idea  Long stable periods interrupted by ___________________periods of _________________ change Docsity.com