BIO FINALS!

• John Ray


  Established the modern concept of a species, noting that members of one species do not interbreed with members of another species. He first used the term species as the basic unit of taxonomy. He also studied fossils and recognized them as remnants of organisms that were once alive.
• Erasmus Darwin


  Charles Darwin's grandfather. Aware that the modern organisms are different from the fossils scientists have collected. Believed that the offspring inherited features from their parents, and that the organisms today descended from a common ancestor.
• Charles Robert Darwin


  Came up with the idea that the best-adapted organisms are those that can survive to breed and pass on their traits to their offspring. Developed his theory of evolution by natural selection as a coherent explanation for the form and distribution of species in different locations.
• Charles Darwin's travels


  1. Reading of scientific books

  2. Collection of plant and animal specimens

  3. Recording of observations, serving as hypotheses on how life changes over time
• Darwin's most famous travel involved a trip to the Galapagos Islands, composed of many small islands located 1,000 kilometers west of South America. The islands have differing climates despite the proximity of the islands with one another.
• Darwin noted that the characteristics of certain animals, such as the shape of tortoise shells or the beaks of birds, vary from one island to another. He also found out that the species present in one location were different from the species found in other locations, and what seemed like animals that look alike may actually belong to several different species (e.g., mockingbird).
• Darwin wrote and published a book entitled On the Origin of Species, in which he proposed the now famous theory of evolution by natural selection. He then presented pieces of evidence demonstrating this process, which according to him has been taking place for millions of years.
• Struggle for existence


  Members of each species compete to obtain food, living space, and other necessities of life. The stronger and faster are able to hunt for food and protect themselves from their enemies.
• Theory of use and disuse


  Organisms could alter the size, shape, or structure of particular body parts or organs by continuously using them in new ways. Unused body parts or organs would eventually decrease in size for several generations until they finally disappear.
• Theory of inheritance of acquired characteristics


  Organisms inherited their traits from their parents, and they may also pass them on to the next generation of offspring.
• Many other observations can be used as pieces of evidence for evolution. These include biogeography or the geographical distribution of organisms, fossil records, DNA and protein sequences, presence of homologous structures, and embryology.
• Homology


  Similarities in the bone structures of the limbs of different vertebrate animals, such as arms, legs, wings, and flippers. These homologous structures may have different functions but are constructed from the same basic features.
• DNA/Protein sequences


  • Chimpanzees have DNA that are identical to humans. Dogs and wolves share many similarities in their DNA sequences.
• Biological diversity is the number and the kinds of organisms living on Earth at a particular time
• Evolution


  The scientific explanation of the diversity of life
• Evolutionary theory


  A well-supported, testable explanation of a natural phenomenon or change over time, is the process of how present-day organisms have descended from ancient ones
• Fitness


  The ability of an individual to survive and reproduce in a specific environment
• Principle of descent with modification


  Species descend through generations with several changes over time and this principle also implies that organisms are related to one another
• Modern phylogenetic tree


  Represents the evolutionary relationships among sets or groups of organisms, called taxa (singular: taxon). The tips of the tree represent the groups of descendant taxa (which are often the species) and the nodes on the tree represent common ancestors of those descendants. Two descendants that split from the same node are called sister groups.
• Directional selection


  Happens when a change in the environment causes a change in the observable spectrum of phenotypes. In this process, organisms with a phenotype that is well suited to their current environment are more likely to survive
• Stabilizing selection


  Occurs when intermediate phenotypes are more likely to survive in the environment
• Artificial selection


  Nature provides the variation among different organisms so that humans can select the variations that are useful to them. This can be done through a technique called selective breeding. This type of mechanism is done by farmers and breeders. In this process, individuals with desirable traits or characteristics are bred to increase the chances of having offspring with the same desirable traits.
• Nonrandom mating


  Contributes to the population change from one generation to the next. This is described as the selected probability of mating with another individual in the population.
• Inbreeding


  When individuals are more likely to mate with their close relatives than with distant relatives. In this manner, individuals choose their mates based on their genetic history. This type of breeding is common, and it results in changes in genotype frequencies, although the frequencies of alleles in the population remain unchanged.
• Founder effect


  Happens when there is a loss of genetic variation because of the migration of a small subgroup in a population. Due to the small population size and the geographical or social isolation of the population from other organisms of the same species, some genetic traits prevalent in the subgroup may lead to the presence of certain genetic diseases in the next generation.
• Substitution effects


  Substitution may cause changes in the protein structure, silent mutations, or change an amino-acid producing codon into a STOP codon, causing a formation of an incomplete protein.
• Frameshift mutation


  Another type of mutation caused by insertions and deletions in the genetic material. This happens when the information is no longer parsed correctly, resulting in the production of useless proteins.
• Cladogram


  A diagram that represents the evolutionary relationships among organisms, with a five-branch pattern reflecting an important assumption that existing groups of organisms divide into five kinds as a new kind of organism arises
• Taxonomy has classified organisms into groups that have biological meaning, helping scientists study different organisms easily and identify threatened and endangered species
• The most recent ways of classifying and naming organisms focus more on genetic and molecular similarities
• Specific epithet examples


  • Felis catus (common cat)
  • Phyllium bonifacioi (leaf insect species found in the Philippines)
  • Dendronotus albus (sea slug)
  • Ixora philippinensis (Philippine santan)
• Specific epithet


  Can be used to indicate the locality, collector, or eminent person
• Specific epithet


  Can be used to describe some of the characteristics of the species
• Specific epithet


  Can be an ecological name, or the habitat to which the organism was first observed
• Taxonomic category


  A group or level of organization, also called a taxon
• Linnaeus's system of classification

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Kingdom


  The largest and most inclusive among the Linnaean taxa, includes the main division where all organisms on Earth are classified
• During Linnaeus's time, he only classified two kingdoms: Kingdom Animalia and Kingdom Plantae
• Phylum


  One of the major taxa used in classifying organisms, includes many different organisms that share important characteristics
• Class


  A subdivision of a phylum, broadly includes the major organisms that are distinct from other organisms internally and externally