Chapter 9 - From Tree Shrew to An Ape Flashcards
what major extinction event occurred 252 million years ago?
Permian-Triassic e.v.
- aka: “the great dying”
what happened during the Permian-Triassic e.v.?
volcanic eruptions resulting in 90% of all species being wiped out
what period followed the Permian-Triassic e.v.?
the Triassic period
what species dominated during the Triassic period?
Therapsids (warm blooded, furred creatures)
what period followed the Triassic period?
the Jurassic period (dinosaurs)
what period followed the Jurassic period?
the Cretaceous period
what extinction event happened 66 million years ago?
the Cretaceous-Paleogene e.g.
- aka “K-Pg”
what happened during the Cretaceous-Paleogene extinction?
a meteorite struck earth, wiping out the dinosaurs and the mammals underwent adaptive radiation
what two factors influenced change in earth’s environments over time?
- continental drift
- climate change
what temperature trend have we seen over the last 20 million years?
a cooling and drying trend
what era follows the Cretaceous period? (and we are in now?)
the Cenozoic Era
- aka “the age of mammals”
what are the 7 epochs within the Cenozoic Era?
- Paleocene
- Eocene
- Oligocene
- Miocene
- Pliocene
- Pleistocene
- Holocene
what epoch showed the first primates?
the Paleocene epoch
what was significant about the Eocene epoch?
the first haplorrhines and strepsirrhines
what epoch is associated with simiiformes?
the Oligocene epoch
what was significant about the Miocene epoch?
the first fossils of apes “the age of apes” in Africa
what epoch showed the first hominins?
the Pliocene epoch
what was significant about the Pleistocene epoch?
showed the first anatomically modern humans
what epoch are we in now?
the Holocene epoch
what epoch was known for erratic temperatures?
the Pleistocene epoch
what importance do deep sea cores have?
they show records of past climate and geology
what importance do oxygen isotopes have?
they show records of past climate, there is a higher O18:O16 ratio in colder climates
what type of anthropologists study fossils?
paleoanthropologists
what is Radio-Carbon Dating?
using radioactive forms of carbon to date fossils, only effective within 60 000 years
what is an isotope?
different forms of the same element based on the number of neutrons
what is a half life?
half of the time it takes for half of a material to decay
what does potassium-argon dating involve?
it uses volcanic rocks surrounding fossils
what is an indirect dating method?
testing the materials surrounding a fossil rather than the fossil itself
what is uranium-lead dating?
uses cave flow stones to determine the age of material
what is the method of thermoluminescence?
testing of the last time a material was heated/exposed to light
what is the method of electron spin resonance?
testing the last time a material was exposed to radiation
what is the method of paleomagnetic dating?
detects shifts in the magnetic field
what is the method of biostratigraphy?
sequences of species buried, that can tell us when a species lived in comparison to others buried there
what are Plesiadapiforms?
- small species with primate like traits from North America
what is the Arboreal Hypothesis?
the idea that primates evolved for life in the trees (e.g. grasping hands, binocular vision)
what is the Angiosperm Hypothesis?
the idea that flowering plants and primates co-evolved
what is the Visual Predation Hypothesis?
the idea that primates evolved to catch insects (e.g. enhanced vision, grasping hands)
what are Adapids?
strepsirrhine ancestors (lemurs), diurnal, quadrupedal, larger than Omomyids
what are Omomyids?
haplorrhine ancestors (tarsiers), nocturnal
describe the Aegyptopithecus
frugivore, sexually dimorphic, 2123 dental formula, arboreal, quadruped (a haplorrhine)
what are the new world vs old world monkeys?
new world: platyrrhines
old world and apes: catarrhines
how did old world monkeys and apes differentiate during the Miocene epoch?
apes became rare, and old world monkeys became plentiful
what is the Proconsul?
the earliest ape ancestor
-> no tail, quadrupedal, frugivore
what is the earliest ape ancestor?
Proconsul
what is Morotopithecus?
one of the earliest ape ancestors
when did the last common ancestor of humans, chimpanzees and gorillas live?
8-10 million years ago
when did the last common ancestor of humans, bonobos, and chimpanzees live?
8-5 million years ago
who may have been an ancestor of Orangutans?
Sivapithecus
