Quiz #2 Flashcards
The transformation of a single species over time
Anagenesis
Species identified from the fossil record based on PHYSICAL SIMILARITIES AND DIFFERENCES with other species along an evolutionary line (lineage)
Paleospecies
The formation of one or more species from another time
Ex: humans, chimpanzees, and gorillas
Cladogenesis
Originally proposed by Niles Eldredge and Stephen Jay Gould (1972), it proposes that most species will exhibit little net evolutionary change for most of their geological history, remaining an extended state called STASIS. When significant evolutionary change occurs it is generally restricted to rare and rapid (on a geologic time scale) events of branching speciation called cladogenesis.
Punctuated Equilibrium
Two different methods to study fossil record
Relative Dating & Chronometric Dating
- Determines which fossils are older (relative to each other)
- Does not determine exact date
Relative Dating
- Layers of earth
- Utilizes the geological process of superposition (the accumulation over time of the earth’s surface)
Stratigraphy/Strata
The older the strata (layers, singular=stratum) are on the bottom, and the younger strata are on the top
Principle of Superposition
The study of the temporal and spatial distribution of fossil organisms
Biostratigraphy
Provides an ‘exact’ date (plus or minus statistical variation)
Chronometric Dating
-Divided into two eons
Geologic Time
(4.6 billion years ago to 545 million years ago)
Precambrian Eon
-545 million years ago to present Broken into 3 geological eras: -Paleozic (545-245 mya) -Mezozoic (245-65 mya) -Cenozoic (65 mya-present)
Phanerozic Eon
- ‘Age of mammals’
- Mammals radiate to fill vacant environmental niches left by the extinction of the dinosaurs
Cenozoic
- 225 mya (plate tectonics)
- last time land was above sea level
Pangea
- Paleocene epoch
- Eocene epoch
- Oligocene epoch
Epochs
65-54 mya B.P
Paleocene epoch
- 54-34 mya B.P
- Frist primate (primative prosimians)
- First anthropoids (man like)
Eocene epoch
- 34-23 mya BP
- Radiation to anthropoids
Oligocene Epoch
- 23-5 mya B.P.
- Radiation of early apes, divergence of apes
- Divergence of apes and hominids
Miocene Epoch
At the end of the mezoic, the earliest likely ancestors of the primates existed
Nocturnal, Arboreal, Insectivores, (like the tree shrew)
An order of mammals adapted to insect eating
Insectivores
- First PRIMATE LIKE mammals in the paleozoic epoch (65-54 mya) .
- Quadraped mammals with arms and legs adapted for climbing.
Plesiadapids
Not mammals
Plesiadapids
Lack postorbital bar (the bony ring separating the eye orbit from the back of the skull in primates
Adaptive Radiation
3-D Spatial orientation required
-Depth perception for leaping from branch to branch
-Overlapping fields of vision needed
-vision more important than smell
Retention of primitive form with 5 digits helps
Good hand eye coordination
Szalay: Requirements for life in trees
Stereoscopic vision and grasping hands first evolved as ADAPTATIONS FOR HUNTING INSECTS ALONG BRANCHES
Visual Predation Model (Cartmill 1974)
Suggest primate origins might relate to eating a mixed diet including fruit/nector/flowers/ rather than only insects
Sussman’s Hypothesis
Newly evolved flowering plants
Angiosperms
When did the first true primates appear?
Beginning of Eocene Epoch 50-55 mya
One group of Eocene primates that were diurnal leaf and fruit eaters is somewhat similar to modern lemurs and lorises
Adapids
Another group of smaller, nocturnal fruit and insect eaters is somewhat similar to modern tarsiers
Omomyids
Anthropoid evolved fairly early, possibly as long as 50 mya, might have evolved from a group other than lemur/loris-like or tarsiers-like primates
Anthropoid origins
Anthropoid fossils first paper in the Eocene Epoch (54-34 mya) in both the Old World and New World
Old World Anthropoids
Where does the most evidence of anthropoid evolution come from?
Africa, South America, and parts of East Asia
Where does the most evidence of New World Monkey Evolution come from?
Fay, Egypt
Earliest fossil record of New World Monkey
30 mya
Single origin for _________, including NWM, in the Old World
Anthropoids
Oldest fossil evidence for apes (mostly dental evidence) is from anthropoids form the _______
Miocene (22-5 mya)
The ________ apes were incredibly diverse until 5-10 mya
Miocene
Lived in Africa 23-17 mya
Genus Proconsul
Lives14-7 mya
-Possibly early ancestor of the modern orangutan
Sivapithecus
