anagenesis Flashcards
(29 cards)
ANAGENESIS
the transformation of a single species over time
PALEOSPECIES
species identified from the fossil record based on physical similarities and differences with other species along on evolutionary line (lineage)
CLADOGENESIS
(branching evolution) formation of 1 more species from another, over time
PUNCUATED EQUILIBRIUM
proposed by Niles Eldridge and Stephen Jay Gould (1972) most species will exhibit little net evolutionary change formats other geologic history, remaining i a extended site called stasis. when significant evolutionary change occurs it is generally restricted to rare and rapid (on a geological time scale) event of branching speciation called cladogenesis.
RELATIVE DATING
Determines which fossils are older (relative to each other) *does not determine exact date
STRATIGRAPHY
strata layers of earth; the accumulation one time of the earths surface.
*utilizes the geological process of super position
SUPER POSITION
the older strata=bottom layer
younger strata= top layer
singular=stratum
BIOSTRATIGRAPHY
study of temporal and spatial distribution of fossil organisms
CHRONOMETRIC DATING
provides an exact date (plus or minus statistical variation
EONS
1) PRECAMBRIAN 4.6 bill -545 mill ya
2) PHANEROZOIC 545 mill- present
ERAS
1) PALEOZOIC 545-245 MYA
2) MESOZOIC 245-65 MYA
3) CENOZOIC 65MYA-PRESENT
CENOZOIC ERA
mammals
- age of the mammals
- mammals radiate to fill vacant environmental niches left by the extinction of the dinosaurs
Pangea 225mya
EPOCHS
1) PALEOCENE 65-54 mya bp
* primate like changes
2) EOCENE 54-34 mya b.p
* first primate (primative prosimians)
* first anthropoids
3) :OLIGOCENE 34-5 mya
* radation of anthropoids
4) Miocene 23-5mya Bp
* radaiton of easy apes divergence of apes
* divergence of apes and hominids
EARLY PRIMATE EVOLUTION
nocturnal, abroreal insectivores
Insectivores: mammals adapted of insect eating
PLESIADAPIDS 65-54
Paleocene
- first primate like mammals
- appeared in the paleocene epoch 65-54 mya
- Quadruped mammals with arms and legs adapted for climbing.
- NOT TRUE PRIMATES
NOT TRUE PRIMATES
lack of postorbital bar (bony ring separating the eye orbit from the bak of the skull
REQUIREMENTS FOR LIFE IN TREES
- 3-D spatial orientation required
- depth perception for leaping from branch to branch
- overlapping fields of vision needed
- vision is more important than smell
- retention of primitive form with 5 digits helps
- good eye coordination helps
VISUAL PREDATOR MODEL (CARTMILL,1974)
stereoscopic vision and grasping hands first evolved as adaptation for hunting insects along branches
SUSSMANS HYPOTHESIS
suggest primate origins right relate to eating:
*mixed diet: fruit, nectar, flowers, gum rather than only insects
FIRST PRIMATES 50-55mya
eocene
appeared 50-55 mya at the beginning of the Eocene epoch (old and new)
EOCENE PRIMATES
OLD WORLD ANTHROPOIDS 54-34 eocene
fossil evidence
southenr climates
*antrpoid first appeareed in the late eocene epoch 54-34 in both old and new world
*most fossil evidence for anthropoid evolution come southern climates in
Africa, South America, and parts of East Asia
*most evidence comes form Fayum Egypt
EVOLUTION OF NEW WORLD MONKEYS
anthropids
30 mya
- Earliest fossil record is 30 mya
- single origin for anthropoids, including new world monkeys in the old world
- The founder generation probably immigrated with rafts and walking to new lands
EVOLUTION OF MIOCENE APES 22-5 mya
fossil eveidence
diverse 5-10
Oldest fossil evidence for apes (mostly dental evidence) is from old world sites from the Miocene (22-5mya)
*miocene apes were incredibly diverse until 5-10 mya
Genus PROCONSUL 23-17
Genus proconsul is believed to be the founding ancestor of all modern apes and humans
*lived in Africa 23-17mya
