Biology
Evolution: A History & a Process
Terms:

A ________________________________ is a group of organisms, or population, that
can be interbreed & produce fertile offspring.

__________________________________________ are the differences found within
species. Ex: eye color and hair color.
o These can be determined by the environment, genetics or both.
o If inherited, it is the result of a random
__________________________________ or
_______________________________________________.

____________________________________________________ are inherited traits
that increase a population’s chances of
__________________________________________ and reproduction in a particular
environment.

A niche is a ______________________________________ and the
_____________________________________ a population plays in that habitat.
o This includes where an organism lives, what & how it eats, how offspring are
raised, where predators are, and space, light, moisture, & temperature.
Darwin’s Theory of Evolution

__________________________________________ wrote The Origin of Species

Describes his idea of evolution:
_____________________________________________________________________

Theory based on observations made when traveling on the
__________________________________________________ around the S.
American coastline, specifically the Galapagos Islands.

Based theory on current thoughts of the time
Influences on Darwin

Evolution means _________________________________________________; process
by which populations change in response to their environment

Georges Buffon suggested the Earth was older than originally believed (few
thousand years).

Jean-Baptiste ______________________________________________ (1809)
theorized that fossils are extinct forms of living organisms found today (in other
words, evolution occurred- the organisms today exist b/c of the fossils; they are the
ancestors). His theory includes 3 points.
Lamarck’s Idea of Evolution:
1. Organisms were striving toward constant
__________________________________________________________.
2. Body parts that were used in life continued to
____________________________________________ whereas unused body parts
waste away. This is the idea of
___________________________________________________________________.
3. Once the structure is modified by use and disuse (#2), the modification is inherited
by the offspring. This is called the inheritance of
__________________________________________________________________.
Think of Dobermans.
Charles Darwin studied finches and many other organisms on the Galapagos Islands. He studied
many factors which influenced his theory of evolution by
_______________________________________________________________________________.

Charles _____________________________________________ hypothesis
about _________________________________________________________:
it occurs extremely slowly & gradually but it can influence plant and
animal life over long periods of time.

Thomas ________________________________________________ (an
economist) idea of
_______________________________________________________________
and populations: Darwin believed this principle could be applied to the
competition of food, water & space and the ability to survive allowed for
reproduction.
Darwin’s Theory of Evolution by Natural Selection:

Darwin wrote a book, On the Origin of Species by Means of Natural Selection, which
explains his theory.

His Theory involves: Descent with Modification:
1. Organisms descended from ____________________________________________ species &
Descendants accumulated different ______________________________________________________
(or adaptations)
2. Natural Selection is the ________________________________________________ for
evolution
Descent with Modification & Natural Selection
This means:

______________________________________________ occur within a population
(they are ALREADY there).

These are ______________________________________________________.
o Understand, all of Darwin’s knowledge was based on observations. He knew
nothing of __________________________________________________.
o Some variations are favorable.

Not all of the young produced in each generation
______________________________________________________.
o This may be the result of disease, lack of food, or they may be victims of
______________________________________________.

Individuals that DO survive and have favorable variations WILL reproduce (and
pass on those favorable variations to the next generation). THEREFORE, the next
generation will have a larger number of offspring with the
__________________________________________________ variations.

Darwin stated ALL organisms were _______________________________________.

He used a tree analogy.
Evidence of Evolution

_______________________________________ are preserved remains, or
imprints, of ancient organisms found in rocks or sediments.

Paleontologists are scientists who study ______________________________

____________________________________________ is the variety & abundance
of species that makeup a biological community.

99% of all types of organisms that ever lived are now
_______________________________________(no longer exists).

Geographic distribution (patterns of life) has provided evidence as well.
Structures

_____________________________________structures are traits such as the human
arm and whale fin that are similar in different species b/c the 2 species share a
__________________________________________ ancestor.
o In this case, the arm and fin have evolved from the forelimb of a vertebrate
ancestor.

Analogous structures are characteristics that are similar in
__________________________________________ but are different in structure in
distantly related organisms.
o Ex: wings of bats and wings of insects.

__________________________________________ structures are structures that are
often small or reduced in size and no longer used but inherited and still present in
organisms.
o Ex: pythons have leg and hip bones, humans have an appendix, manatees
have leg bones.

____________________________________________ is the study of early
developmental stages of organisms.
o Scientists use this, along with biochemistry, to study and understand
evolution.
Other Evidence

Developmental: stages of _____________________________________ devo are
similar

Molecular: similar _________________ sequences

Selective breeding to produce a desired trait is
______________________________________ selection (think dog breeding).

Example of Natural Selection in Action:
_________________________________________________________________

Pesticides are ___________________________________________ (kill insects that
destroy crops & homes)

Some insects are resistant to pesticides (have genes); they survive & reproduce
(passing on this trait).

Understand, insects do not _____________________________________ resistant;
they already had the genes for resistance!
Concept 14.5 NS & SCA

_____________________________________________________ (SCA) is a genetic
disease affecting the shape of RBCs, creating symptoms of fatigue, body pain,
organ damage & sometimes death.

There is a ____________________________ frequency of SCA in Africa and even
higher frequency of heterozygous individuals
WHY?

Heterozygous SCA have resistance to ____________________________________
(plasmodium, organism that causes malaria, does not reproduce well w/in sickleshaped RBCs); this is called the
__________________________________________________________________.
Antibiotic Resistance

____________________________________________ are medications that kill (or
inhibit the reproduction of) bacteria

Some bacteria are resistant to antibiotics (again, this is b/c they contain genes for
the resistance).

Antibiotic _________________________________________________allows the
st
bacteria that survive the 1 round of antibiotics to reproduce & pass on the
_____________________________________ for resistance.

This is becoming a health concern.