Download Chapter 5 Outline APES

Chapter5
Evidence for the evolution of life comes from:
A.
B.
C.
D.
A.
chemical experiments.
fossils.
chemical analysis of ancient rocks and core samples.
DNA mutations.
Chemical Experiments
The Earth's primitive gaseous atmosphere was
 methane.
 ammonia.
 water vapor.
 nitrogen.
The source of energy used to the synthesis of biological chemicals on primitive Earth is
 ultraviolet light.
 radioactivity.
 lightning.
 sunlight.
The origin of organic molecules on Earth came about by 3 theories
 formation of organic molecules from gaseous inorganic molecules and an energy
source
 formation of organic molecules around hydrothermal vents in the ocean floor
 formation on dust particles in outer space
Fossil History
The fossil record is incomplete because
 not all fossils have been found.
 some fossils have decomposed.
 some life forms left no fossils.
Fossil come from
 bone
 leaves
 teeth
 shells
Chemical analysis of ancient rocks and core samples and Fossil history proved:
1. The distance of the earth from the sun has created a temperature just right for the evolution of life that is
dependent upon water.
2. The size of the earth has enough mass to gravitationally attract the atmosphere.
3. Biological evolution of life is anaerobic prokaryotes-photosynthetic prokaryotes-aerobic
prokaryotes-eukaryotes-multicellular organisms.
4. Current hypothesis about the earth's is that cyanobacteria produced atmospheric oxygen by using
photosynthesis
5. The oxygen revolution was most likely brought about by cyanobacteria
Mutations
Mutations are a source of new genetic material.
Mutations can be caused by
 ultraviolet light.
 X rays.
 certain chemicals.
 Radioactivity
A gene pool is the genetic composition of a population.
Evolution is called a change in the genetic composition of a population over successive generations
Microevolution is the term that describes small genetic changes that a population within a species experiences
An example of this the changes in coloration within the population of peppered moths is an example of
microevolution.
macroevolution is The term used to describe the long-term, large-scale evolutionary changes among groups of
species
The change from a light to a dark color in the peppered moth was the result of industrial pollution
1. directional natural selection is when natural selection results in a shift toward one end of a normal range
of traits
2. stabilizing natural selection is when natural selection results in a shift toward the average of a range of
genetic expressions for a particular trait
3. disruptive natural selection is when natural selection shifts allelic frequencies toward the extremes of a
range of genetic expressions for a particular trait
4. coevolution is called over the course of time, the change in the gene pool of one species may lead to
the change of the gene pool of another species.
Coevolution can involve the interaction of
 plants and herbivores.
 pollinators and flowers.
 parasites and hosts.
 plant roots and fungi.
Coevolution
 occurs when interacting species exert selective pressures on each other.
 occurs between plants and the herbivores that eat them.
 may play a role in the evolution of camouflage.
Niche and Habitat
An organism's niche is analogous to its way of life.
An ecological niche includes
 nutrient relationships with other species.
 types of resource requirements.
 range of tolerance to different physical and chemical conditions.
 types of competitors.
Habitat is the location where a species lives.
convergent evolution. is species belonging to different taxonomic groups may develop a resemblance resulting
from adaptation to similar environments.
Extinction
 Genetic diversity helps prevent a species from becoming extinct.
 The phenomenon in which animals with favorable adaptation reproduce more
rapidly is called differential reproduction.
Geographic isolation is a common mechanism contributing to speciation
Geographic isolation may result from a(n)
 volcanic eruption.
 earthquake.
 mountain range.
 river
Geographic isolation gives rise to
 reproductive isolation.
 speciation.
 divergent evolution.
 microevolution.
Types of Evolutionary Changes
1.
2.
3.
4.
5.
dynamic equilibrium.
a steady state hypothesis.
a punctuated equilibrium hypothesis.
a gradualist model of evolution.
natural selection.

Darwin's description of macroevolution as an accumulation of steady, small evolutionary changes is
best described as a gradualist model of evolution (a gradualist model of evolution is evolutionary
change occurs at a slow but constant rate, with small changes accumulating over time.)
a steady state hypothesis is new matter is continuously created as the universe expands.
dynamic equilibrium is constantly shifting and changing, at the COMPONENT LEVEL, in order to
maintain a stable, organized configuration at a PATTERN LEVEL.
natural selection is survival of the fittest
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Gould's view of macroevolution as long periods of relatively little change interrupted by short periods
of relatively rapid change is best described as a punctuated equilibrium hypothesis.

For your knowledge
Punctuated equilibrium says that in long periods of time, mutations simply accumulate but do not cause any
drastic phenotypical changes, followed by short periods where these mutations are suddenly expressed. This
would account for the lack of transitional fossils in many phylogenic branches.
Gradualism is the model that says mutations and phenotypical changes are gradual and explain the fossil
record gaps as simply missing because fossils are hard to find.
common misconception about evolution are
 Evolution is a grand plan of the perfecting of species.
 In a Darwinian world, the strongest survive.
 Humans evolved from apes.
 In a Darwinian world, the biggest survive.
True fact about evolution is that the key to survival in a Darwinian world is coexistence through occupying
different niches.
Biodiversity and Extinction
1. Biodiversity is believed to be the result of speciation and extinction.
2. Extinction history and views
 Biologists estimate that 99% of all the species that have ever existed are now
extinct.
 Mass extinctions raise the extinction rate above the background extinction rate.
 Most mass extinctions are believed to be due to global climatic changes.
 Earth has experienced over a 5 great mass extinctions.
3. It takes on the order of 10 million years for adaptive radiations to rebuild biological diversity after a
mass extinction.
4.
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Patterns of speciation and extinction are affected by
climatic changes.************
continental drift.
meteorites crashing into the earth.
human activity.