Studied by 6 people
Formation of the Earth
4.6 billion years ago
The oldest thing on Earth, a zircon, was found in:
Australia
Plate tectonics have a profound impact on Earth’s living systems and our understanding of them. Why?
The configuration of the continents helps determine ocean circulation. Geographic isolation and proximity can be drivers of evolution. Subduction has destroyed most of the older rocks on Earth, thus destroying any fossils that might have existed in them.
What are the earliest fossils on Earth?
Biomarkers, isotopic fractionations and chemical fossils
Formation of the Moon
4.5 billion years ago
Initiation of plate tectonics
3 billion years ago
Oxygenation of the Earth
2.5 billion years ago
The event that occurred between 2400 and 2200 mya (2.4 and 2.2 billion years ago) and enabled life as we know it today was:
The Great Oxidation Event
Scientists who study fossils of organisms other than humans are:
paleontologists
Fossil beds are composites. This means:
They may include fossils brought in from somewhere else. They are time-average.
The atmosphere of the Early Earth consisted primarily of:
Nitrogen and carbon dioxide
The study of sequences of rocks in time is called:
stratigraphy
Fossils are:
evidence of life preserved in rocks
Fossils are preserved in __________ rocks
sedimentary
The three types of fossils are:
body, trace, and chemical
What has to happen for an organism to become a fossil?
Death, rapid burial, preservation, lithification (becoming a rock), erosion and exposure
The Green River shale, Burgess Shale, Solnhofen Limestone and Chengjiang are examples of:
lagerstatten
The vast majority of fossils are found in:
sediments deposited in shallow lakes, lagoons or flood plains
The study of hierarchical relationships and naming of organisms is called:
taxonomy
The paleontology species concept is NOT based on
DNA
One of the best examples of an evolutionary series that is strong evidence for evolution was collected by:
O.C. Marsh
A fundamental grouping of organisms that descended from a common ancestor is a:
phylogeny
What is NOT a problem for paleontologists when setting up a new species?
Evolutionary series
Ontogenetic, population and taphonomic are all types of
variation that hinder paleontologists in recognizing species
The environment in which sediment was laid down is called
depositional environment
The relative time scale used by all geologists world-wide is mostly based on
marine fossils
Replacement/Permineralization fossil
Dissolved compounds in ground water swap out shell and skeleton material
Cast/Mold fossil
Sediment fills in around and inside the organism and the hard parts dissolve
Chemical fossil
chemicals preserved that provide an organic signature for life including itsotopes and biomarkers preserved in rocks
Mummification fossil
Organism is desiccated and preserved in a very dry environment
Freezing fossil
Organism is preserved in ice
The processes involved in fossilization are known as
taphonomy
Convergent evolution
Similar structures or traits that develop independently on different organisms to solve the same problem
Darwin’s preferred model of evolution was
phyletic gradualism
Erasmus Darwin was
Charles Darwin’s grandfather, thought transmutation was driven by competition and sexual selection and all life came from a common ancestor but didn’t have evidence
Jean-Baptiste Lamarck was
The man who developed the first cohesive theory of evolution after his studies of biology, called it transmutation and thought acquired traits were inherited
A species can have one of two fates
Extinction or speciation
Body fossils
Hard parts of an organism, such as bone, teeth or shells
Trace fossils
not actual biological material but provide evidence of the activities of ancient organisms, coprolites, tracks, eggs
Natural selection is driven by
competition for sexual partners, space and food
Natural selection
The process in which heritable variations that result in better adaptations to a changing environment result in a new species
phyletic gradualism
evolution that occurs slowly in a very stable environment
punctuated equilibrium
pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change, unstable environment
extinction
to die out completely
background extinction
the extinction that goes on all the time in relatively small numbers, caused by biological causes and natural selection
mass extinction
when global extinction rates rise dramatically for a geologically short time
mass extinction characteristics
geologically rapid, involves a significant number of organisms from different phyla and is global
how many mass extinctions have there been?
5 (Ordovician Silurian, Devonian, Permian Triassic, cretaceous-tertiary)
The generally accepted cause of the end-Cretaceous mass extinction was
a meteorite/bolide impact
evidence for a meteorite impact at the end of the Cretaceous includes
high iridium levels, tektites and shocked quartz
The crater believed to be the one formed by the end-Cretaceous meteorite is near
the Yucatan Peninsula, Mexico
The largest mass extinction was
end-Permian (or Permian-Triassic), 95% of marine animal species exterminated, entire classes & orders disappeared
The cause of the end-Permian mass extinction is
still not known for sure, but the ocean became inhospitable
explosive radiation
the geologically sudden increase of global species diversity
mass extinction results in
explosive radiation due to vacant ecological niches
Most of the body plans on Earth arose
during the Cambrian radiation
The three evolutionary faunas recognized by Jack Sepkoski are
Cambrian, Paleozoic, Modern
Which phyla has no symmetry?
sponges (Porifera)
The basis of Functional Morphology is
form follows function
In functional morphology, biomechanics is used to
decide what really is possible
In evolution, compromise occurs because
nature is parsimonious and wants to use the fewest resources, therefore it will not expend energy for an unnecessary adaptation
Convergent evolution demonstrates functional morphology because
similar structures evolve to solve the same problems
Convergent evolution happens because
there are a limited number of morphologies that will perform a function successfully
We figured out what a Dire Wolf looked like by using
comparison
Functional morphology
the study of structural adaptations an organism makes to its environment and lifestyle
What is not true of morphological features?
They are usually neutral (features are NOT usually neutral, meaning they almost always have a purpose, a neutral feature would be eye color)
paleontology
the study of fossils
What are problems with the fossil record?
Physical destruction, rarefaction (preservation bias), age bias
Biological species concept
species is a group of populations whose members have the potential to produce fertile offspring
ontogenetic variation
changes that you can see between young individuals and old individuals of the same species
population variation
genetic differences between local populations
taphonomic variation
when geological processes like plastic deformation change the shape of a bone, resulting in apparent anatomical differences
microevolution
evolutionary change within a species or small group of organisms, especially over a short period
macroevolution
large-scale evolutionary changes that take place over long periods of time
divergent evolution
dissimilar organs that have a similar origin and underlying anatomy
What are the nature of morphological features?
they are mostly adaptive, very few neutral (non-functional) features, only a limited number of ways an organism can adapt to its environment, most options are already in use by extant organisms, many fossil morphological features can be extrapolated from a living equivalent, adaptation is non-random
pseudo fossils
not actual fossils, they are minerals or rocks that happen to look like fossils
unaltered/original material
dead organism has been incorporated into the rock but has not undergone the permineralization or replacement processes
permineralization
new material fills in the void spaces of a dead organism
replacement
the organisms original materials are replaced with new ones
bilateral symmetry
the organism is mirrored down the center
radial symmetry
the organism has repeated segments arranged around a central point
chirality
symmetry that involves rotation as well as reflection
five-point symmetry
the organism has five matching segments repeated around a central point, ex. starfish
Note
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