Study sets, textbooks, questions
Upgrade to remove ads
Geo. Test 2
Terms in this set (54)
arrangement of visible layers of rock
-Represents a change in the kind of sediment being laid down in one place
-A change in the environment!
-Refers to sequence of different kind of rocks
-Usually meters thick
- packages of sediment in a certain rock type, usually represents subtle changes of deposition
-Measured in centimeters
inclined beds of sediment (usually sand) in a horizontal unit of rock.
the bouncing motion of particles, collides and loosens other particles
Could be the result of a flood or typical stream deposit
stream flowing in one direction
tidal current since oscillating flow
Wet clay dries and contracts; may show drying of puddle or if extensive, drying of lake beds
Importance of fossils in sedimentary rocks
- 98% of fossils are found in sed rock
-Type of fossil - ocean, freshwater, land
-Organism tells much of the ecosystem:
-predator - prey relationships
-prehistoric food chain
-adaptations to environment
-position of the continents
-Tell conditions of the Earth/locale
-Pollen grains show when plant species evolved and died out
bodies of sediment containing physical, chemical, and biological attributes that tell the story of environmental deposition.
Study of the origin, correlation, deposition, and formation of layered rocks through principles of chemistry, physics, paleontology, and ecology.
an educated prediction based on a couple of observations and a few facts.
an explanation in science based on numerable experiments and observations
-Organisms are arranged from simple to complex
-Species are fixed, permanent
-Earth is young (Gen 1-2)
-Doesn't say species are fixed nor evolving
-Fossils were interpreted to be from the Great Flood described in Genesis.
Put organisms in order by similar characteristics (taxonomy):
-Testing the Great Flood
-Sediment sizes and organisms should show a pattern of arrangement
-Observations don't support the idea of a Great worldwide flood.
-Fossil record shows a sequence of greater complexity through time
-History of life is recorded in rock strata containing fossils:
-Each stratum contains a unique assemblage of fossils
-The older the stratum of rock, the more dissimilar the fossils are to present-day species.
-Extinctions take place where species appear and later disappear.
-First piece of evidence that species weren't fixed
John-Baptiste de Lamarck
First to propose how organisms could change or evolve:
1st part - A body part used extensively will become bigger and stronger
Traits are acquired during an organism's lifetime
2nd part - "inheritance of acquired traits"
Improved traits are passed along to offspring
Implication - takes a vast amount of time for a species to change from "acquired traits"
-Mainly responsible for Theory of Evolution
-Went on scientific expedition (The Beagle) to sail along the west coast of South America
today's organisms have descended with modification from ancestors that lived in the past.
similar individuals that in nature breed and produce fertile offspring
-a rare change in the DNA of genes within a sex cell that ultimately creates genetic diversity.
-The chemical structure of the gene is changed; changes genetic information that is passed on
-Mutations occur by an errors during DNA replications in the sex cell
-Mutations can be a positive, neutral, or negative change
-Most mutations occur in isolated populations from others of its kind
-Organisms in all populations possess heritable variations from one another
-Some variations are more favorable in terms of survival
-Not all young survive to reproductive maturity
-Those organisms with more favorable variations are more likely to survive and pass on these heritable traits.
the gradual accumulation of minor changes eventually brings about the origin of a new species
-Takes a tremendous amount of time
-little or no change takes place in a species existence, then evolution occurs rapidly.
-Gives rise to a new species within a few thousands of years
-Mass extinction of species contributes to open niches in ecosystem
Organisms that are distantly related but developed similar characteristics because they occupy similar niches in the ecosystem.
Organisms have recently evolved characteristics as well as some features of their ancestral parents.
nonfunctional structures in a living organism that were functional for their ancestor
Evidence of evolution
1. Oldest fossil-bearing rocks should be very different from today's species, more recent rocks more similar to today's species.
-Transitional fossils are identifiable fossils between modern species and their predecessors
3. Geography determinant
Prevalent Theory - same climate should produce same species (NOT TRUE)
-Major isolated land areas and islands have distinct animal and plant communities
4. Molecular level
-All living things are made from the same molecular structures
-Only 20 kinds of amino acids are used create genes (in animals)
-All living organisms are made of cells consisting of proteins, fats, carbohydrates, and water
-See process of natural selection in microbes and in selective breeding of dogs and flowers.
6. When 2 species diverge, their ancestors should be similar. Further divergence creates greater differentiation.
7. Potential of new species evolving at the present
Origin of life
-The origin of life is NOT part of theory of evolution.
-How life began from non-living matter is a big question
mainly because the absolute complexity of the cell
Importance of evolution theory
-A universal theory that explains many observations we see:
-Explains The rise of complexity of organisms in the fossil record
-Explains why species are similar and different
-Diversity of life found on Earth present and past
-How organisms modify traits over time
-Foundation of biology
-99.9% of all species that ever lived have gone extinct.
-Extinct species weren't "weak" or inferior.
-Dinosaurs dominated for 150 million years
-Most species in the fossil record last a few million years
-others lasted an immense amount of time before coming extinct.
-Some species don't change for millions of years: Coelacanths (oldest living jawed fish - 410 Ma)
-Most extinctions are Background Extinctions:
-The animal/plant simply disappears from the fossil record
-Other species at the same time period don't disappear
-A failure to adapt to new conditions in its environment (natural selection).
-About 2 - 5 families of organisms become extinct every million years.
a catastrophe where many species are wiped out at once.
Differences between background and mass extinction:
-Major changes to the worldwide environment occurred to create mass extinction.
-In mass extinctions, widespread species can also be wiped out.
-But if a species is widespread across the globe, has a better chance to resist extinction.
-In geologic time, 5 major extinction events
2 theories behind why extinction occurs
1st theory - a specie's failure to adapt to new conditions
2nd theory - bad luck from random accidents
-Widespread organisms have better chance to live in worldwide catastrophe
any record of past life that has been preserved in the Earth's crust.
6 ways to become a fossil
1.Petrification - living cells replaced by minerals slowly over time
2. Freezing - animals/plants entrapped in ice
-Can have entire remains preserved: soft tissue, stomach contents, hair
3.Dessication - mummified animals preserved in arid regions
-Water is removed to atmosphere and prevents bacterial decay
4. Burial - buried in tar pits, peat bogs, or embedded in wax/resin deposits
-Tar pits: soft tissue decays, but have original bones pickled in petroleum
5.Molds/Casts - outlines of animals or their tracks
-Additional sediment hardens in form of animal outline or track
6. Carbonization - a thin film of carbon left by a plant or animal on a layer of rock, same process as coal
-Mostly plant fossils
what fossil records show
1. Less predators, more prey
Mirrors modern ecosystem populations
2. Absences in fossil record - soft body tissue animals
3. Statistically, difficult for an organism to become a fossil
any change of shape or volume to a rock.
Types of Stress
1.Tension: forces acting in opposite directions on a rock
2.Compression: forces directed toward each other on a rock
3.Shear: forces acting parallel to one another on a rock
Fracture vs. Plastic behavior
-Under stress, a rock will fracture close to the surface of the Earth, down to 5km in depth
-Most powerful earthquakes occur near the surface
-Depths past 5km, rocks will usually plastically deform
Mineral grains slide by each other in rock, but rock stays cohesive
-Evident in folds
when a plane in a rock is crumpled or bent
an up-arched fold where older rocks are in the middle
a down-arched fold where youngest rocks are in the middle
the angle of an inclined plane to an imaginative horizontal plane
rigid layer of less dense rocks, 5-70 km thick.
crust and upper mantle
-proposed in 1915 that continents were once together in a landmass called Pangaea (Greek for "all land")
-continental crust floated on oceanic crust since less dense.
Evidence of Drift Theory
-Fit of continental shelves/mid-ocean ridges are better examples
2.Matching types of rocks and ages
-Same types and age of rock found on separate continent
3. Matching mountain ranges
-Matching Appalachian range from Georgia to Norway
-Glaciation on tropical continents - all southern continents
-Land fossils on separate continents:
Cygnonathus - mammal-like reptile in Triassic
mammal-like herbivore, found in southern continents
reptile returned to water
a species of tree, large seeds
Recommended textbook explanations
Pearson Earth Science
Applications and Investigations in Earth Science
Dennis G. Tasa
Sets with similar terms
Chapter 6 Fossils
Ch 5 Evolution
Science Chapter 5 and part of 6
Other sets by this creator
Criminal Investigations Midterm
Criminal Law Exam chapter 7-11 Final
Criminal Law Exam 2
Other Quizlet sets
France Unité 5
HIST 1015 Quiz Questions
organization of nervous system BCS ppt5