Download Evolution - Mr. Gittermann

EVOLUTION
EVOLUTION:

Any change in the genes of a population over
time
ORIGIN OF LIFE:
Big Bang Theory:
explosion of a mass of
matter to create the
universe
 4.6 billion years ago

ORIGIN OF LIFE THEORIES
Abiogenic Molecular Evolution:
a) Organic molecules gradually assembled from
inorganic elements
b) Hildane – “Hot Dilute Soup”, combination of
Earth’s primitive atmosphere (H20, CO2, Ammonia)
and UV radiation created organic molecules
c) Oparin – energy from the sun, lightning, and
volcanic heat formed organic molecules
EVOLUTIONARY THEORY BASICS:
1)
2)
Gradualism: slow change over time
First cell was probably a “protocell”
1)
2)
3)
4)
3)
Membrane bound cell that reproduced
Heterotrophic
Prokaryotic
Originated probably four billion years ago
Life may have originated more than once
EVOLUTION OF EVOLUTIONARY THEORY:
1)
Georges Cuvier:
Catastrophism: Only one time of creation that
populated the entire world, global catastrophe
wiped out most of them.
2)
Jean Baptiste de Lamarck:
Theory of Inherited Characteristics: environmental
pressures and “internal desires” bring about
physical changes that would be that would be
passed on to offspring
EVOLUTION OF EVOLUTIONARY THEORY:
Charles Lyell:
Theory of Uniformity: The same geological
processes that are occurring now, happened
in the past as well
*An issue for scientists as most people thought
the world was only six thousand years old as
noted in the Bible.
3)
CHARLES DARWIN:
Naturalist aboard the
H.M.S. Beagle for a
five year exploration
 His notes became the
basis of his
evolutionary theories
and book, The Origin
of Species

BEGINNING COMPONENTS OF NATURAL SELECTION:

Used his notes on Finches, especially in
regards to their beak and diet to create his
framework
THEORY OF NATURAL SELECTION:
a)
b)
c)
d)
e)
f)
More offspring are produced than can survive
All members must compete for resources
All organisms show individual variations mostly
due to heredity
Some variations are better adapted to survive
These organisms that are more likely to survive
therefore reproduce, therefore increase
frequency of better adaptations
Change over long enough time results in new
species
POPULATIONS:
Individuals do not evolve, populations over time
do
 A group of individuals of the same species who
occupy the same area
 Gene Pool: all the genes present in a
population, population shows variation

SOURCES OF VARIATION:
1.
2.
3.
4.
5.
Gene mutation (produces new alleles)
Crossing over at meiosis (leads to new
combinations of alleles in chromosomes)
Independent assortment at meiosis (Anaphase I
& II, leads to mixes of maternal and fraternal
chromosomes in gametes)
Fertilization (puts together combinations of
alleles from two parents)
Changes in chromosome number or structure
(lead to loss, duplication, or alteration of alleles)
MICROEVOLUTION:
Changes of gene frequencies within a
population
 Caused by: mutation, genetic drift, gene flow,
and natural selection

MUTATION:
Heritable change in DNA that can alter gene
expression
 Can be neutral, harmful, beneficial, or lethal
 Original sources of alleles and thus variation

GENETIC DRIFT:

Random change in gene frequencies over the
generations as brought about random events
only
GENE FLOW:
Allele/gene frequencies change as individuals
leave a population or new individuals enter a
population
 Physical movement of genes

PEPPERED MOTHS:
DEVELOPMENT OF NEW SPECIES:
Species: A group of organisms that breed and
produce offspring that can reproduce
 Speciation: The development of a new species
from an existing species

SPECIATION:

Reproductive Isolation:
groups of the same
species can not contact
each other and adapt to
separate environments,
and thus develop into
different species
SPECIATION:
Adaptive Radiation: One common ancestor
develops into different species based on
competition, location, food supply, etc.
 Ex: Darwins finches

MACROEVOLUTION:
Large evolutionary changes in which new
species emerge
 Punctuated Equilibrium: new species suddenly
emerge
 Gradualism: Gradual, slow change over time
with intermediate organisms found.

EVIDENCE FOR EVOLUTION:
1.
Fossil Record:
a)
b)
c)
Sequence of fossils
Rocks formed in layers with older ones on bottom
Fossils in older layers are older and simpler
COMPARATIVE ANATOMY:
Comparing anatomical structures of current
organisms with each other and past organisms
 Vestigial Organs: have no current function;
appendix, wisdom teeth, penguin wings, little
toe
 Homologous Structures: Same structure in two
organisms but different functions

EMBRYONIC DEVELOPMENT:

Similarities in the developmental stages of
embryos amongst different organisms