GENBIO FINALS REV

• Dating methods

  • Relative dating
  • Absolute dating
• Relative dating


  Estimate, not specific dates, only classify as younger and older
• Absolute dating


  Specific origin, specific time range in years
• Absolute dating - Isotope decay


  • Used to determine the range
• Geologic time scale


  The "calendar" for events in Earth history, divided into named units of abstract time called: Eons, Eras, Periods, and Epochs

  
• Precambrian life

  • Hadean Eon
  • Archaean Eon
  • Proterozoic Eon
• Hadean Eon


  Named after the Greek god and ruler of the underworld, Hades, dated minerals at 4.4 billion years, with evidence that liquid water was present, unlikely that life could have formed and established in the extremely volatile conditions
• Archaean Eon


  Archaea exists, no oxygen gas on Earth/in the atmosphere, complex chemical reactions in the young oceans transformed carbon-containing molecules into simple, living cells that did not need oxygen to live, oxygen only in compounds such as water, Archaeans - extreme bacteria, life on earth started on water
• Proterozoic Eon - Ediacaran Period


  First appearance of algae, invertebrates, eukaryotic cells, and blue-green (Cyanobacteria), first oxygen-dependent animals formed, the Ediacara fauna
• Phanerozoic Eon


  • Paleozoic Era
  • Mesozoic Era
  • Cenozoic Era

  
• Paleozoic Era


  • Cambrian Period
  • Ordovician Period
  • Silurian Period
  • Devonian Period
  • Carboniferous Period
  • Permian Period
• Cambrian Period


  The time when many kinds of invertebrates and the first vertebrates appeared, first fish appeared: Agnathans (jawless fish), Cambrian Explosion - Most of the major animal groups started to appear in the fossil record, a time of rapid expansion of different forms of life on Earth

  
• Ordovician Period


  Fungi, plants, and animals colonizes the land
• Silurian Period


  First vascular plants appeared, Vascular Plant - Ability to transport food and water
• Devonian Period


  Bony fishes diversified, insect and first amphibians appeared
• Carboniferous Period


  First seed plants appear, origin of reptiles and amphibians dominate
• Permian Period


  Reptiles diversify, major extinction of marine organism (96%), three of every four species on land died out
• Mesozoic Era


  • Triassic Period
  • Jurassic Period
  • Cretaceous Period
• Triassic Period


  Dinosaurs evolve, origin of mammals, gymnosperms dominate, gymnosperms - naked seeds

  
• Jurassic Period

  Dinosaurs abundant, first birds appear, gymnosperms dominate
• Cretaceous Period


  Angiosperms diversify, angiosperms - coated seeds, bears fruits, dinosaurs extinct at the end of this period
• Cenozoic Era

  • Paleogene Period
  • Neogene Period
  • Quaternary Period
• Paleogene Period

  • Paleocene Epoch
  • Eocene Epoch
  • Oligocene Epoch
• Paleocene Epoch


  Mammals, insects, birds diversify

  
• Eocene Epoch


  Angiosperms dominate
• Oligocene Epoch


  Origin of primates; Purgatorius, dating back as far as 65 mya
• Neogene Period


  • Miocene
  • Pliocene
• Miocene


  Mammals and angiosperms continue to diversify
• Pliocene


  Bipedal human ancestor; Ardipithecus ramidus
• Quaternary Period


  • Pleistocene Epoch
  • Holocene Epoch
• Pleistocene Epoch


  Ice ages and origin of Homo
• Holocene Epoch


  The time since the end of the last major glacial epoch or "ice age"; the current time we are living in
• Mass extinction


  A short period of geological time in which a high percentage of biodiversity, or distinct species dies out
• Evolution

  The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth, the gradual development of something, especially from a simple to a more complex form
• Evidence of evolution


  • Fossil records
  • Biogeography: evidence from geographic distribution
  • Comparative anatomy
  • Vestigial structures
  • Molecular biology
• Fossil records


  The most direct evidence of evolution, we need to study fossils and sedimentary rocks to learn about past environment and climatic condition, fossils are the preserved remains of previously living organisms or their traces, dating from the distant past, sedimentary deposits contain fossils, remains, or traces of animals, plants, and other organisms from remote past, through dating of rocks on which they were found, the accurate age of the fossils is determined
• Dating methods


  • Relative dating
  • Absolute dating
• Relative dating


  Rocks and the fossils that were generally in the deeper strata were assumed to be older while the younger ones were those found in the upper part
• Absolute dating


  Rocks are dated through radiometric age dating where the most significant factor considered to identify a rock age is the degree of radioactive decay. The older the rock, the more isotopes are decayed
• Biogeography


  The discipline of biology that studies the present and past distribution patterns of biological diversity and their underlying environmental and historical causes, broad organisms that had already evolved before the breakup of the supercontinent Pangea (about 200 million years ago) tend to be distributed worldwide, in contrast, broad groupings that evolved after the breakup tend to appear uniquely in smaller regions of the earth (Endemic Species), the patterns of new habitat, migrations, adaptation of species in response to new environments, divergence from the ancestral population, and the formation of the noel species, are chiefly apparent on islands