Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
The Mesozoic Era- Mammals Develop 1. Pangaea began breaking apart resulting in earthquakes, volcanoes, and mountain building. 2. The Mesozoic has three periods: the Triassic, Jurassic and Cretaceous. Triassic hot climate, the Atlantic ocean forms mammals appear- They have hair or fur, and most offspring are born live, not from eggs trees and ferns are still common first dinosaurs appear- They are small, no bigger than chickens, have small heads, long tails and walk on their hind legs Mesozoic: Jurassic “ Age of Dinosaurs” – “Jurassic Park” Two main groups of dinosaurs based on hip structure Ornothischia (bird hipped) had 5 main categories Stegosaurus, ankylosaurs, ceratopsians, pachycephalosaurs, & ornithopods They were mainly herbivores Bob Gardner's "Dinosaurs" Planetarium Show, The Evolutionary Relationships of Dinosaurs Sauruschia were the lizard hipped dinosaurs- there were two types Sauropods- quadrupedal (four legs), herbivores Brachiosaurus, Brontosaurus, Apatosaurus Theropods- bipedal (two legs), carnivores Tyrannosaurus Rex Velociraptor Sauropods Mesozoic: Jurassic Cont… First bird appearedArchaeopteryx Means “ancient wing” Bird with teeth and reptile skeletal structure Transition fossil Between reptiles and birds Cretaceous period Dinosaurs still flourishing sea level has dropped, waters dry up first flowering plants End of the Cretaceous Period and Mesozoic Era At the end of the Cretaceous period and the Mesozoic Era is the mass extinction of most life on earth. A meteorite hit in the Yucatan Peninsula off the coast of Mexico. This caused enormous explosions, tsunamis, wildfires, and so on. Over time, the dust from the collision that rose into the atmosphere blocks out the sunlight plunging the earth into colder temperatures. This results in starvation of many species or the inability to adapt to a new climate and their extinction. Today we see a layer of Iridium around the world to support this. Cenozoic “Age of New Life” A world with people Began 65 million years ago, after the meteorite impact Divided into 2 periods -> Tertiary –for evolution of 1st horses. Quaternary- for evolution of 1st animals to walk on 2 feet. Near end of Tertiary, humanlike creatures began to walk upright on African plains-“Lucy” found in 1977 (3.4 myo) 3.Primates are mammals with opposable thumbs and two eyes in the front of the skull. They have nails vs. claws, they care for infants and they have higher intelligence. 4. Homonoids include three groupings- the great apes, the lesser apes and the Hominids. Homonids are bipedal. The hipbone supports the upright walking, also have larger brains, smaller faces and greater dexterity. Evolution: Change over time Evolution is change over time A species is a group of organisms that can SUCCESSFULLY interbreed, produce fertile offspring Ex. Lions and tigers are similar and can breed (producing Ligers or Tigons) BUT offspring are NOT fertile- Not same species. Ex. A horse and a donkey can mate and result in a mule but it’s not fertile- Not the same species. Ex. A beagle and a German shepherd look different but share similar characteristics. Can breed and produce fertile offspring –same species. Liger Tigon Horse + Donkey = mule + = A gene is a unit of heredity that is passed from parent to offspring. Ex. eye color, hair color, length of arms, etc. A mutation is a change in gene. Can be good or bad. Mutations: Agents of Change 1. After most mutations the organism can’t survive and dies, often before birth. 2. However, sometimes it’s a positive change. 3. A change that increases organisms’ chances of survival is an adaptation. 4. Better adapted =more offspring =so many adaptations may take place that a new species evolves! May result in extinction of previous species. Evolution Example Bacteria Jellyfish Fish Worms Amphibians Reptiles Dinosaurs Birds Lizards Mammals Primates Felines Humans Lions TeacherTube Videos - Simpsons Evolution