This document discusses biodiversity and classification of living organisms. It defines biodiversity as the variety of species in a region, including different ecosystems and genetic diversity. It describes levels of biodiversity at the genetic, community, and landscape levels. Certain regions are identified as biodiversity hotspots with high concentrations of endemic species. The history of classification systems is reviewed, from early systems distinguishing plants and animals, to the modern 5-kingdom system (Monera, Protista, Fungi, Plantae, Animalia). Binomial nomenclature and the hierarchical categories of domain, kingdom, genus and species are also defined.
2. Biodiversity refers to the total number of
species found in an area.
Includes the large variety of species, different
ecosystems and genetic differences.
Endangered species: species in danger of
extinction
Threatened species: species likely to become
endangered in the near future
4. Ecologists describe biodiversity as an
attribute of three other levels of biological
organization:
Genetic diversity: variation among members of a
population, higher genetic diversity higher chance
of survival.
Community diversity: community composition,
increases the levels of biodiversity.
Landscape diversity: a group of interacting
ecosystems within one landscape.
5. Biodiversity not
evenly spread
throughout
biosphere
Protecting some areas
will save more species
than protecting other
areas
Regions of the world
are called
biodiversity hotspots
Contain unusually large
concentrations of
species
CAPE REGION
6. INDIGENOUS
SPECIES
Occurs in a place
naturally
Native
A species can be
indigenous to a
number of places at
once
ENDEMIC SPECIES
Occurs naturally
only in that place.
Native to an
exclusive or limited
area.
Not widely
distributed won't
be found naturally
anywhere else.
e.g. Madagascar Flying Fox
endemic to Madagascar
7. More than a million species of living
organisms discovered and described
Estimated 賊30 million species still to be discovered
Scientists involved in describing species are
called taxonomists
8. Plant & animal species identified exhibit great
deal of variation
In form, structure, mode of life & other aspects
Plants & animals need to be divided into
discrete groups based on the differences
In order to study them.
9. Classification: the scientific practice of
identifying, naming and grouping of living
organisms.
Branches of biology that deal with
classification:
Taxonomy deals with describing and naming
organisms.
Systematics deals with grouping and arranging the
described taxa into a hierarchical classification.
10. Makes studying living organisms convenient.
Helps in specific identification of an organism.
Study of a few representatives from each distinct
group helps to integrate idea of life as a whole.
Reveals relationships among various groups of
organisms.
Provides information about plants and animals
occurring in specific geographical regions.
Indicates evolutionary relationship
Establishing gradually increasing complexity of form and
structure in different groups of organisms.
11. ARISTOTLE (Greek philosopher)
1st to classify organisms
Either as plants or animals
He formulated the 2 kingdom system = Plantae
and Animalia
Plant group subdivided into 3 smaller groups:
shrubs, herbs, and trees.
Animals subdivided into groups according to
where they lived: on land, water or in the air.
12. Ernest Heackel
Proposed adding a third kingdom = Protista
Robert Whittaker (1969)
Expanded the classification system to five
kingdoms
Organisms were placed in these kingdoms based
on type of cell, complexity, and type of nutrition
All prokaryotes were placed in the monera
kingdom.
Organisms without a membrane bound nucleus
13. Carl Woese (1970)
Proposed 2 groups of prokaryotes after
researching the rRNA
Bacteria
Archaea
These also fundamentally different from each
other
Should be assigned to separate domains
(higher classification category than a kingdom).
Thus formulated a 3 domain system =
Bacteria, Archaea and Eukarya
15. Linnaeuss System
Carolus Linnaeus (Swedish Botanist)
developed a method of classifying organisms
properly.
Based on classifying according to physical &
structural similarities.
E.g. he might use the similarities in flower parts as
a basis for classifying flowering plants.
Became foundational way for todays modern
classification systems.
16. Modern classification systems use a two-word
naming system called Binomial Nomenclature
Bi: two
Nomial: associated with a name
Species is given a unique and stable name
Meant that each species is composed of two
Latinised words (similar to name & surname)
1. Genus
2. species
17. First word identifies the genus name of the
organism.
A genus (plural form = genera) consists of a
group of similar species.
Second word, the species, often describes a
characteristic of the organism.
Scientific name = the Genus name + species
name
18. Example: Homo sapiens (wise man)
Note:
Genus name begins with capital letter
Species name begins with lower case letter.
Both names are always italicized or
underlined
Example: Sutherlandia frutescens or
Sutherlandia frutescens
19. Latin is the language of scientific names
Many organisms have common names just
like you might have nicknames.
Example:
Sutherlandia frutescens (scientific)
Cancer bush / Kankerbos (common)
Accepted by speakers of all languages
Each name applies only to one species
Each species has only one name
20. A Kingdom is the largest group in the
classification system
Encompasses all the related species
Living organisms are subdivided into 5 major
kingdoms:
MONERA
PROTISTA
FUNGI
PLANTAE
ANIMALIA
(Organisms cannot belong to more than one)
21. Kingdom Monera
Consists of all bacteria simple, single celled
organisms with no nucleus
22. Kingdom Protista
Consists of single celled or simple multi-
cellular organisms
Some obtain energy by photosynthesis
algae.
Some ingest other organisms
Some absorb molecules through the cell
membrane
E.g. Amoeba, Euglena.
23. Kingdom Fungi:
Single celled e.g. yeast- to multi cellular
organisms
Body composed of very fine threads
saprophytic nutrition
24. Kingdom Plantae:
Plants
Multi cellular terrestrial organisms
Cells have cell walls, obtain energy through
photosynthesis
Kingdom Animalia:
Animals
Multi cellular, aquatic and terrestrial organisms
Cells have no cell wall, feed on other organisms
Editor's Notes
The Archaea are a group of single-celled microorganisms.
Eukarya: The domain comprised of eukaryotes or organisms whose cells contain a true nucleus