Download 5. Evolution and Biodiversity State Frameworks Central Concepts

EVOLUTION AND NATURAL SELECTION NOTES
5. Evolution and Biodiversity State Frameworks
Central Concepts: Evolution is the result of genetic changes that occur in constantly
changing environments. Over many generations, changes in the genetic make-up of
populations may affect biodiversity through speciation and extinction.
5.1 Explain how evolution is demonstrated by evidence from the fossil record,
comparative anatomy, genetics, molecular biology, and examples of natural
selection.
5.2 Describe species as reproductively distinct groups of organisms. Recognize
that species are further classified into a hierarchical taxonomic system (kingdom,
phylum, class, order, family, genus, species) based on morphological,
behavioral, and molecular similarities. Describe the role that geographic
isolation can play in speciation.
5.3 Explain how evolution through natural selection can result in changes in
biodiversity through the increase or decrease of genetic diversity within a
population.
EVOLUTION AND NATURAL SELECTION NOTES
Chapter 15 Darwin's Theory of Evolution
Our natural world presents us with a puzzle about life's diversity. Homo
sapiens share Earth with millions of other species with every imaginable
shape, size, and habitat. This variety is called biological diversity. How did
all these different organisms arise? How are they related?
Theory- well supported testable explanation of phenomena that have occured
in the natural world.
Evolutionary Theory-is a collection of scientific facts, observations, and
hypotheses which can account for this diversity of life.
Evolution - change over time. Process by which modern organisms have
descended from ancient organisms.
1700's: There is not much debate about the evidence that, based on fossil
records, organisms have changed over time.
The big debate is the MECHANISM for evolution. What caused organisms to
evolve.
EVOLUTION AND NATURAL SELECTION NOTES
Jean-Baptiste Lamarck 1744-1829
France 1809: described the 1st theory of evolution.
*simplest creatures from spontaneous generation
*series of transformations to more complex
organisms.
*his work is weakened due to lack of evidence as to
a mechanism for these transformations.
Lamarck suggests:
*animals become more complex because they strive to be better. This
desire for improvement fuels the transformations.
*traits acquired during the life of an organism are passed on to the next
generation.
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Jean-Baptiste Lamarck 1744-1829
How Lamarck explains the evolution of giraffes with longer necks.
Fiddler crab example
EVOLUTION AND NATURAL SELECTION NOTES
Jean-Baptiste Lamarck 1744-1829
Pro's: Removed God as the instigator of life. Animals change
through time. changes make them better adapted to their
environment.
Lamarck is vilified in the scientific community due to his lack of
evidence. Common sense should tell us that traits acquired during
life are not passed down to the next generation.
With a neighboring classmate, come up with an
example that refutes "Lamarckism" as the mechanism for
evolutionary change.
1889 Weismann (Germany) Mice
EVOLUTION AND NATURAL SELECTION NOTES
Charles Darwin 1809-1882
*1831-1836 Voyage on the HMS Beagle
*His findings, collections, and experiences
effect his thinking.
*Has an abundance of evidence that he will
use as support for his theory.
Ideas that helped shape Darwin's theory:
*Rich fossil record was challenging the traditional view of life.
*James Hutton (1795) and Charles Lyle (1830)- Earth is many
millions of years old and the processes that changed Earth (erosion,
volcanism) in the past are the same processes that operate in the
present.
*Thomas Malthus (1798)- notes that human birth rate is faster than
death rate. Reasons that if the human population continues to grow
unchecked, sooner or later there would be insufficient living space and
food for everyone.
EVOLUTION AND NATURAL SELECTION NOTES
Charles Darwin 1809-1882
Upon his return on the Beagle, he filled notebooks with his ideas
about the diversity of life and how many closely related organisms
were uniquely adapted to their particular environment.
1838- Darwin is convinced
that Natural Selection is the
mechanism for evolutionary
change.
EVOLUTION AND NATURAL SELECTION NOTES
Charles Darwin 1809-1882
Charles Darwin's criteria for evolution by natural selection:
*Populations increase in size therefore increasing competition for resources such as food,
living space, etc.
*Not all organisms are equally equipped for the competition for resources
*There is always variation for each trait in a population. These variations are inherited
from parents.
*Organisms with slightly better variations, that allow them to survive in their
environment, survive and breed. Those with less beneficial variations do not survive
and breed.
*Useful or beneficial characteristics of survivors are passed to their offspring.
*Over time, populations gradually change to better adapt to their environment.
EVOLUTION AND NATURAL SELECTION NOTES
How Darwin explains the evolution of giraffes with longer necks.
Fiddler crab example
EVOLUTION AND NATURAL SELECTION NOTES
Lamarckism vs. Darwinism
EVOLUTION AND NATURAL SELECTION NOTES
Charles Darwin 1809-1882
1838 Charles Darwin is convinced that Natural Selection is the
mechanism for the change in organisms over time yet he waits another
20 years before he publishes! Why?
*continues to collect evidence to support and avoid Lamarck's fate.
*avoid shock waves in society and religion.
"God-less lanscape for life"
What causes him to publish The Origin of Species by Means of Natural
Selection in 1859?
502 pages of
evidence.
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Alfred Russell Wallace
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vs.
Wallace was an admirer of Darwin and was inspired by his Beagle
voyage.
He sent Darwin a paper detailing his idea on Evolution by Natural
Selection and asked for Darwin's critique!
Deal was brokered and they presented there papers together in London
in 1858. The Origin of the Species by Means of Natural Selection is
published in 1859 and Darwin considered the Father of Evolution.
Interesting Note: Darwin cannot explain HOW traits are passed from
parents to offspring. Do you know anyone at the time who could?
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I Can Help!
Gregor Mendel
1822- 1884
Who am I?
EVOLUTION AND NATURAL SELECTION NOTES
Mendel orders 40 reprints of
his paper, Experiments in
Plant Hybridization (1865), by
Gregor Mendel and sends
them to many famous
scientists at the time.
Was Darwin one of them????
EVOLUTION AND NATURAL SELECTION NOTES
Evidence for Evolution
Evolution- Change in the genetic makeup (phenotype) of a population over time
Fossils in sedimentary rock
Homologous anatomy
Analogous organs
Vestigial structures
Comparative embryology
Fish
Salamander
Turtle
Chicken Rabbit
Biochemistry: DNA and Protein
sequence similarities
Human