Transcript BIOLOGY NOTES EVOLUTION PART 1 PAGES 14-15, 368-386

BIOLOGY NOTES
EVOLUTION PART 1
PAGES 297-319
Standards:
5.1
____Explain
how the scientific theory of evolution is
supported by the fossil record, comparative
anatomy, comparative embryology, biogeography,
molecular biology, and observed evolutionary
change
____
5.2 Describe the conditions required for natural
selection, including: overpopulation of offspring,
inherited variation, and the struggle to survive,
which results in differential reproductive success
5.3 Describe how mutation and genetic
____
recombination increases genetic variation
5.12
____ Explain how and why the genetic code is
universal and is common to almost all organisms
Essential Questions:
1. What mechanisms have allowed for
diversity in organisms?
2. How is the scientific theory of evolution
supported by different disciplines?
I. Evolution = the biological process of
change by which ____________
descendents come to
_______
differ from their __________
ancestors
A. History
1. Carolus Linnaeus (1700’s) – proposed that
fixed but do change over
organisms are not _____
time from breeding experiments
organisms so similar
• species = a group of __________
to one another they can reproduce and have
______
fertile offspring
2. Georges Louis Leclerc de Buffon (1700’s) –
shared ancestors
proposes that species _______
instead of arising separately
3. James Hutton (1795) & Charles Lyell (1833)
– two geologists who discovered that the Earth
was really ________,
millions not thousands, of years
old
theories by
• Hutton and Lyell broke former ________
studying rock layers and suggesting
geographical formations due to weather,
erosion and other natural forces occur
________,
slowly. Thus, the Earth must be ________
millions of
years old.
4. Thomas Malthus (1798) – An economist who
suggested that human population growth is
_______
limited by resources such as food, water and
space. A population that grew too large would
struggle for existence.
result in a ________
• This led evolutionists to wonder if ________
animals
also competed as animals generally have even
more offspring than humans
5. Jean Baptiste Lamarck (1809) – A scientist
acquired
who proposed the theory of _________
characteristics
• Lamarck believed that an organism’s ____
use or
disuse of a trait determined if it were passed
on to _________
offspring
e.g.fiddler crab claw, birds flying
• This is an obviously ________
incorrect hypotheses
behavior cannot affect
because an organism’s ________
it’s heredity
• Lamarck’s hypotheses were important,
however, because he is the first scientist to
suggest that organisms do, in fact, _______
change
over time and are ultimately adapted to their
environment
____________
6. Alfred Wallace (1858) – A scientist whose
Malaysia confirms Darwin’s theory
studies in _________
of _________
evolution
5. Charles Darwin – proposed the modern
evolution through the
scientific theory of _________
natural selection
MECHANISM of _______
• Studied different fossils, collected evidence,
and made numerous observations while on
H.M.S. Beagle in 1831
board the _____________
 got most of his evidence from the
__________
Galapagos islands
• Published the ______
Origin of Species in 1859 with
his mechanism (how it happens) of evolution
B. Darwin’s Modern Theory of Evolution
Premise #1: Individuals differ and these
inherited (passed on to
differences are _________
offspring)
• At this point in time Mendel’s work was not
very well known so Darwin did not know ____
how
variation among organisms occurred
• Darwin, however, did know variation occurred
among ________
different species by observing and
recording variation among _________
hundreds of
organisms
e.g. finches, tortises, etc.
• with Mendel’s work, we now know this variation
occurs at the genetic level and we call the
alleles
variations for a single trait _______
• with a better understanding of genetics we now
mutations
know variation occurs because of ___________
and during _______
sexual reproduction / _________
crossing
over
Premise #2: Organisms _________
compete for limited
resources.
• Struggle for existence = members of the
same ________
species regularly compete for _____,
food
living space, etc.
• Members of the same species compete
overpopulation
because of ______________
• Fitness = the ability of an individual to _______
survive
and reproduce in its environment
 each organism has advantages or
disadvantages in the struggle for survival
_______
 adaptation = any inherited _____________
characteristic
that increases an organism’s chances of
survival
________
• If the environment changes, something that
may have been an _____________
adaptation could or
could not be of use
e.g. dinosaur size
Premise #3: Within each species competition,
there are winners and ______
losers
• Natural Selection (a.k.a.) Survival of the
adapted to
fittest = those organisms best ________
their environment survive to reproduce and
these organisms pass on their traits (acts on
___________)
phenotypes
• Evolution occurs through _______
natural selection
(also known as the MECHANISM of evolution)
Conclusion #1: Those species of organisms that
descendent from a
are alive today are ____________
common ________
ancestor but, have been _________
modified
or changed over time (EVOLUTION)
• As natural selection occurs, species gradually
become very ________
different from each other
• this is what Darwin termed ________
descent with
modification
____________
C. Evidence for the Scientific Theory of Evolution
1. Fossils = preserved remains or _________
evidence
of the existence of an organism
e.g. dino bones
• This tells us that there have been a _______
variety of
different organisms alive over millions of _____
years
older the
• The lower in the rock layers, the _____
organism is believed to be
• Within millions of years there are large _____
gaps
decomposition
WHY? ______________
a. most fossils are found in ____________
sedimentary rock
b. other types of fossils include: ______,
casts amber
preserved fossils, petrified fossils, imprints, and
______
molds
c. as ____________
paleontology continues, many missing
discovered
“links” have been ___________
2. Homologous Body Structures = structures
function but the same
that have different ________
basic _________
structure
e.g.bat wings, human hand, whale flipper
• Similar structures indicate similar genetic codes
in the _____
DNA molecules of an organism
universal and
• Remember the genetic code is _________
millions or even billions of base pairs long in
every cell
• It is unlikely that long sequences of matching
different species
base pairs exist in two ________
unless these organisms evolved from a
common ancestor
_________
sequencing
• this can be proven using genetic ___________
3. Vestigial Organs = organs present within an
function
organism that serves no useful ________
e.g. human appendix
• Why would organisms have organs they do not
use?
 if the organs do not affect the survival of
life then natural selection would not have
____,
eliminated these organs
 this can also explain why there are
unused pieces of DNA found in almost all
________
_____________
organisms
• The presence, however, of vestigial organs
species could
suggests that several different _______
ancestor
have evolved from a single ________
4. Embryology
• Many organisms look similar in structure as
embryos which indicates they have a common
________
_________
ancestor
e.g. rat, human, chicken
• Why do organisms eventually look extremely
different from embryo to full grown individual?
cell differentiation
________________
Larva
Adult crab
Adult barnacle
5. Molecular & Genetic Evidence = it has been
species have similar
shown that very different ________
molecular and ________
genetic mechanisms
• the more related two organisms are, the
more _______
related their DNA will be
• pseudogenes = sequences of _____
DNA
useful
nucleotides that are no longer _______
pseudogenes reflects a
 having similar _____________
ancestor
common _________
distribution
6. Biogeography - Geographical ____________
of common plants & animals
e.g. Whale bones in African desert
7. Observed Evolutionary Change
e.g. Spread of antibiotic resistant bacteria