BIO

• Precambrian Era


  • Hadean eon
  • Archean eon
  • Proterozoic eon
• Hadean eon


  • Earth takes 10 million years to cool: initial atmosphere escapes into space (H&He) and the core forms (Fe&Ni)
  • No life possible as the Earth initially formed 4.6 billion years ago
• Archean eon


  • Volcanic outgassing of water and carbon dioxide occurred for millions of years, helping to build atmosphere and then oceans
  • Simple, single-celled forms of life appeared 3.8 billion years ago. They will become more complex and successful over the next 3 billion years: Prokaryotes than Eukaryotes
• Proterozoic eon


  • At 3 billion years ago, banded iron formation rocks appear due to rising oxygen levels in the atmosphere and sea
  • Cyanobacteria begin producing free oxygen (photosynthesis)
• Paleozoic Era


  • Cambrian Period
  • Ordovician Period
  • Silurian Period
  • Devonian Period
  • Mississippian Period
  • Pennsylvanian Period
  • Permian Period
• Cambrian Period


  • Explosion of life
  • All existing phyla came into being here
  • Life forms in warm seas as oxygen levels rose enough to support life
  • Dominant animals: trilobites and brachiopods
• Ordovician Period


  • Great extinction due to growth of ice caps including in what is now northern Africa
  • First animals with bones appear
  • Dominant animals: marine invertebrates including corals and trilobites
• Silurian Period


  • Extensive erosion
  • First land plants appear and land animals follow
• Devonian Period


  • Dominant animals: fish
  • Amphibians, evergreens and ferns appear
  • Pre-pangea forms
• Mississippian Period


  • First seed plants appear
  • Much of North America is covered by shallow seas and sea life flourishes (bryozoa, brachiopods, blastoids)
• Pennsylvanian Period


  • Modern North America begins to form
  • Ice covers the southern hemisphere and coal swamps formed along the equator
  • Lizards and winged insects first appear
• Permian Period


  • 90% of Earth's species become extinct, including trilobites, blastoids, fish and amphibians because of heavy volcanism
• Triassic Period


  • First dinosaurs appear (Coelophysis, Chindesaurus, Plateosaurus)
  • First mammals- small rodents appear (Eozostrodon)
  • Life and fauna re-diversify
  • Rocky Mountains form
  • Pangea breaks apart
• Jurassic Period


  • Pangea still breaking apart
  • Dinosaurs flourish "Golden age of dinosaurs"
  • First birds appear
  • North America continues to rotate away from Africa
• Cretaceous Period


  • T-Rex develops but number of dinosaur species decline
  • Snakes appear and first primates appear
  • Angiosperms appear
• Paleocene Epoch


  • First horses appear (size of a cat)
  • Tropical plants dominate
• Eocene Epoch


  • Grass spreads widely
  • Diverse array of animals develop, including whales, rhinos, and elephants
• Oligocene Epoch


  Cats, dogs, and apes appear
• Miocene Epoch


  Horses, mastodons, mammoths, tigers, and camels live in South Carolina
• Pliocene Epoch


  Hominids develop (Australopithecus anamensis)
• Pleistocene Epoch


  • Modern humans develop and ice sheets are predominant (Ice Age)
  • Asians arrive and settle the Americas
• Holocene Epoch


  • Mastadons become extinct
  • Human culture flourishes
  • Accelerating extinction of many species
• Heritability


  The extent to which traits are passed down from parents to offspring through genetic inheritance
• Differential reproductive success


  Occurs when individuals with advantageous traits are more successful at surviving and reproducing than individuals with less advantageous traits
• Selective Mating


  1. Choosing specific individuals with desired traits to mate and produce offspring with those traits

  2. Relies on natural reproductive processes and genetic variation within populations
• Hybridization


  1. Crossing individuals from different populations or species to combine desirable traits from each parent

  2. Can lead to the creation of hybrids with novel combinations of traits not present in either parent population
• Genetic Engineering


  1. Direct manipulation of an organism's genome to introduce or enhance specific traits

  2. Techniques such as gene editing, gene insertion, or gene suppression to achieve desired outcomes
• Precision Breeding


  • Advances in molecular biology and genomics have enabled breeders to apply precision breeding techniques, targeting specific genes or genetic regions associated with desired traits
  • Allows for more targeted and efficient breeding strategies
• Evidences of Continental Drift Theory:

  1. Fit of the continents
  2. Fossil Records
  3. Geological Similarities
  4. Paleoclimate indicators
• Arthur Holmes proposed the idea that the mantle undergoes thermal convection to finally give Wegener’s Continental Drift Theory a viable mechanism.
• Lithosphere


  The outermost layer of the Earth, consisting of the crust and the uppermost part of the mantle. It is divided into several large and small pieces called tectonic plates.
• Asthenosphere


  Below the lithosphere lies the _, which is a semi-fluid layer of the upper mantle. It behaves like a plastic solid over long periods of time, allowing the overlying lithospheric plates to move.
• Tectonic Plates


  Large, rigid pieces of the Earth's lithosphere that float on the semi-fluid asthenosphere. These plates are composed of oceanic or continental crust or a combination of both.
• Seafloor Spreading


  At mid-ocean ridges, magma rises from the mantle and solidifies to form new oceanic crust. As the crust forms, it pushes older crust away from the ridge, leading to the expansion of the seafloor.
• Subduction


  One tectonic plate is forced beneath another into the mantle due to differences in density. This process results in the formation of deep oceanic trenches and volcanic arcs.
• Collision


  When two continental plates converge, neither is dense enough to be subducted, so they collide and buckle, forming vast mountain ranges like the Himalayas.
• Transform Faulting


  Along transform boundaries, tectonic plates slide past each other horizontally. The friction between the plates can cause earthquakes as stress builds up and is released along faults.