Evolution is any change in the genes of a population over time. The origin of life theories propose that organic molecules assembled from inorganic elements in the primordial atmosphere and oceans around 4 billion years ago. Charles Darwin's theory of natural selection proposed that populations evolve over generations as individuals with favorable variations are more likely to survive and reproduce, passing on those variations. Evidence for evolution includes the fossil record showing sequences of simpler to more complex organisms over time, comparative anatomy revealing homologous and vestigial structures, and similarities in embryonic development across species.

1. EVOLUTION

2. EVOLUTION:
 Any change in the genes of a population over
time

3. ORIGIN OF LIFE:
 Big Bang Theory:
explosion of a mass of
matter to create the
universe
 4.6 billion years ago

4. 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

5. EVOLUTIONARY THEORY BASICS:
1) Gradualism: slow change over time
2) First cell was probably a “protocell”
1) Membrane bound cell that reproduced
2) Heterotrophic
3) Prokaryotic
4) Originated probably four billion years ago
3) Life may have originated more than once

6. 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
passed on to offspring

7. EVOLUTION OF EVOLUTIONARY THEORY:
3) 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.

8. 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

10. BEGINNING COMPONENTS OF NATURAL SELECTION:
 Used his notes on Finches, especially in
regards to their beak and diet to create his
framework

11. THEORY OF NATURAL SELECTION:
a) More offspring are produced than can survive
b) All members must compete for resources
c) All organisms show individual variations mostly
due to heredity
d) Some variations are better adapted to survive
e) These organisms that are more likely to survive
therefore reproduce, therefore increase
frequency of better adaptations
f) Change over long enough time results in new
species

12. 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

13. SOURCES OF VARIATION:
1. Gene mutation (produces new alleles)
2. Crossing over at meiosis (leads to new
combinations of alleles in chromosomes)
3. Independent assortment at meiosis (Anaphase
I & II, leads to mixes of maternal and fraternal
chromosomes in gametes)
4. Fertilization (puts together combinations of
alleles from two parents)
5. Changes in chromosome number or structure
(lead to loss, duplication, or alteration of
alleles)

14. MICROEVOLUTION:
 Changes of gene frequencies within a
population
 Caused by: mutation, genetic drift, gene flow,
and natural selection

15. MUTATION:
 Heritable change in DNA that can alter gene
expression
 Can be neutral, harmful, beneficial, or lethal
 Original sources of alleles and thus variation

16. GENETIC DRIFT:
 Random change in gene frequencies over
the generations as brought about random
events only

17. GENE FLOW:
 Allele/gene frequencies change as
individuals leave a population or new
individuals enter a population
 Physical movement of genes

18. PEPPERED MOTHS:

19. 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

20. SPECIATION:
 Reproductive Isolation:
groups of the same
species can not contact
each other and adapt to
separate environments,
and thus develop into
different species

21. SPECIATION:
 Adaptive Radiation: One common ancestor
develops into different species based on
competition, location, food supply, etc.
 Ex: Darwins finches

22. 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.

25. EVIDENCE FOR EVOLUTION:
1. Fossil Record:
a) Sequence of fossils
b) Rocks formed in layers with older ones on
bottom
c) Fossils in older layers are older and simpler

27. 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

30. EMBRYONIC DEVELOPMENT:
 Similarities in the developmental stages of
embryos amongst different organisms