What Is a Species?
A
population or group of
populations whose members
have the ability to breed with
one another in nature and
produce fertile offspring.
Microevolution refers to change in the
allele frequencies within a population.
Macroevolution :
These changes include:
-the origin of different species,
-the extinction of species, and
-the evolution of major new features
of living things, such as wings or flowers.
Speciation
The origin of new species is
known as
speciation
Geographic Isolation and Speciation
Geologic processes constantly change and
rearrange Earth's features.
 This change can separate different
populations of one species.
Ex: A mountain range may gradually emerge,
slowly splitting a population of organisms
that cannot cross it.
Separation of populations as a result of
geographic change or dispersal to
geographically isolated places is called
geographic isolation.

What Is Taxonomy?
Classification of living things is
called "Taxonomy."
This is when scientists put
organisms into groups when they
have things in common.
The first groups they use are the
Kingdoms.
There are five kingdoms
-Animal Kingdom
-Plant Kingdom
-Fungi Kingdom
-Protist Kingdom
-Moneran Kingdom
Now represented by 2 kingdoms
Each Kingdom is then split into smaller
groups, called Phyla.
Each Phylum is split into smaller groups
called Classes,
Each Class is split into Orders,
Each Order is split into Families,
Each Family is split into Genera,
Each Genus is split into Species.
As each group is split into
smaller groups,
the organisms are more
and more alike.
A Five-Kingdom Scheme
 It
places prokaryotes such as
bacteria in the kingdom Monera.
 Organisms of the other four
kingdoms all consist of eukaryotic
cells.
 The kingdoms for plants, fungi,
and animals consist of
multicellular eukaryotes.
The Linnaean System of
Classification
The system of classification most widely
used in biology dates back to Swedish
botanist Carolus Linnaeus (1707–1778).
 The system has two main characteristics—
a two-part Latin name for each species
and a hierarchy, or ordering, of species
into broader and broader groups.

Scientists from around the world agreed to
use the ancient language of Latin to give
organisms, and their groups, names.
Sometimes a group will have a "Common
Name" and a fancy, scientific Latin name.
For example, there is a Family of frogs
called "Ranidae" (Scientific Latin name).
This Family's common English name is
"Tree Frogs."
Every Species gets a fancy scientific
Latin name.
A Bullfrog is also known as "Rana
catesbeiana."
A White-tailed Deer is known as
"Odocoileus virginianus.“
A Monarch butterfly is known as
"Danaus plexipus."
One thing that makes it easier
to understand all these names
is to know that a Species
always has a first and a last
name
The first name is also the
name of the Genus group that
Species is in.
So the Monarch butterfly is
known as Danaus plexipus
and it is in the Danaus genus.
Notice that the first name of a
Species is always capitalized,
while the second name is not.
Species are classified into groups
within groups. A diagram that reflects
such hypotheses of evolutionary
relationships has a branching pattern
called a phylogenetic tree
-The diagram's name comes from
the word phylogeny, meaning
"evolutionary history.
Three Domains
 In
the last decade, molecular data
and cladistics have led to a
reevaluation of the five-kingdom
system.
 A three-domain system as one
alternative to the five-kingdom
system.
 A domain is a taxonomic category
above the kingdom level.
This newer scheme recognizes
three basic groups: two domains of
prokaryotes—the Bacteria and the
Archaea—and one domain of
eukaryotes, the Eukarya.
The Bacteria and the Archaea differ
in a number of way. What is most
important to understand here is that
classifying Earth's diverse species
of life is a work in progress.