1. Classification of Living Things
Taxonomy, Hierarchical Classification, Binomial Nomenclature, Genetic Variation, Relatedness, Phylogeny

2. Kingdoms Classification – we all do it
Main classification by Aristotle
Plantae and Animalia
Does not always fit – sponges and corals fixed in one place however they do not make their own food through photosynthesis
Microscopes further clouded the process
Haeckel (1866) – created a third kingdom
Protista
"first established beings“
"better regarded as a loose grouping of 30 or 40 disparate phyla with diverse combinations of trophic modes, mechanisms of motility, cell coverings and life cycles.”

3. Kingdoms Fungi – were originally included with Plants
They do not carry out photosynthesis though and absorb food into their bodies
Bacteria – lack a nucleus and other organelles and can gain energy in a variety of environments
They were given their own kingdom as well
Sometimes known as Eubacteria, Prokaryotae or Monera
Archaea – kingdom created in the 1990’s
For bacteria that live in very unique environments
Acidic springs, salt lakes, hot springs

4. Kingdoms

5. Prokaryotes & Eukaryotes
Two main types of cell types based on differences in size, structure and other characteristics
Fossil evidence
Prokaryotic cells – 3.5 billion years ago
Eukaryotic cells – 1.5 billion years ago
Multicellular organisms – 700 million years ago

6. Kingdoms - subdivided Domains
Bacteria
Archaea
Eukarya
Within Eukarya we find the protists and it is believed that they should be further divided
Agreement is difficult

7. Taxonomy Classifying organisms Carolus Linnaeus – circa 1750
Taxis – arrangement; Nomos – law
Carolus Linnaeus – circa 1750
Used physical characteristics to classify organisms into groups
Latin and Greek stems (Felis domesticus)
Names given often reflect characteristics of organism or to honour a scientist or historical figure

8. Hierarchy of Groups Horse is more like a dog then a shark
Horses and dogs are mammals
Horse is more like a shark then an oyster
Vertebrates vs. invertebrates
Each kingdom is broken down into smaller groups called taxon (plural taxa) to assist with categorization
Kingdom is largest down to species

9. Hierarchy of Groups
Plantae--includes all plants
Magnoliophyta--flowering plants
Magnoliopsida--dicots
Magnoliidae--subclass for Magnolia-like plants
Magnoliales--order for Magnolia-like plants
Magnoliaceae--family for Magnolia-like plants
Magnolia--genus includes all Magnolias
grandiflora--specific epithet
The name for a species consists of the genus name and the specific epithet. **Notice that the endings will always tell you what rank you are dealing with, even if you don't recognize the word. For example, the word "Sterculiaceae" could only refer to a family.
As you go up, each category is made of groups of members of the category below it--e.g., there are many types of Magnolia but they all fit into the genus Magnolia. The Magnolias and their relatives are all in the Magnoliaceae. Orders are made up of families, subclasses are made of orders, etc.

10. Binomial Nomenclature
Using two words for each species
Genus and species names used
Canis lupus (wolf); Canis latrans (coyote); Canis familiaris (domestic dog)
Common Names
Problematic because they are not standard
Mountain lion, puma and cougar
P. 395, fig

11. Origins of Diversity
Similar to others in your species but not exactly the same
Diversity between species begins within a species
Certain different characteristics found between two populations in response to their environment may allow new species to develop
First described in 1859 by Charles Darwin in his book: On the Origin of Species by Means of Natural Selection

12. Genetic Variation Changes in characteristics are produced by:
Random genetic mutations
Introduce variety
Especially important in asexual organisms
Selection for a particular characteristic that increases the organisms chance of survival and breeding in a particular environment

13. Determining Relatedness
Taxonomy involves evolution
A need to determine the evolutionary history of groups of organisms
Comparing different species living today with those that lived in the past
Ways by which scientists determine relatedness
Anatomy, development, biochemistry, DNA

14. Evidence from Anatomy
Classification between major classes can be difficult
Archaeopteryx – 150 million years ago
Fossils not required to find anatomical evidence of evolution
Human arm, horse’s leg, bat’s wing and whale’s flipper
All specialized for what they do but they have the same evolutionary origin - homologous

15. Evidence from Anatomy

16. Further Evidence Development
Relatedness due to appearance can be a dangerous mistake
Larval and adult forms of organisms can be very different and they are the same species!

17. Further Evidence Biochemistry
Comparisons due the molecules from which organisms are made
Comparisons of proteins and hormones
Horseshoe crab is more similar to spiders then to other crabs

18. Further Evidence
DNA
Genes consist of sequences of nucleotide bases in a segment of DNA
Human single strands of DNA are compared to other organisms and the amount of complementary base pairing that occurs indicates relatedness
93% match with the macaque monkey
98% match with the chimpanzee
DNA can also help to determine how long ago species began to diverge from a common ancestor
Mitochondrial DNA – mother to offspring
It mutates at a predictable rate so it provides a molecular clock for measuring rates of evolution

19. Phylogeny “True” evolutionary history of groups of organisms
Common ancestors share characteristics of all organisms that come after in a phylogenetic tree
Smaller differences help to distinguish genus’ from each other

20. Phylogeny Order Artiocactyla Family Bovidae – horns
Even number of hoofed toes on hindfoot; specialized teeth and digestive systems for vegetation
Family Bovidae – horns
Family Cervidae – antlers
Genus Cervus – highly branched antlers
Genus Rangifer – broad, palmate antlers (hand shaped)

21. Phylogenetic Tree

22. Cladistics Classification scheme based on phylogeny
Based on idea that each group of related species has one common ancestor
The current organisms retain some ancestral characteristics and gain some unique characteristics as they diverge from the ancestor
Cladogram – like a phylogenetic tree but is used to test alternative hypothesis about differences in branching history

23. Phylogeny vs. Cladistics
A phylogenetic tree is a specific type of cladogram where the branch lengths are proportional to the predicted or hypothetical evolutionary time between organisms or sequences
The term "cladogram" emphasizes that the diagram represents a hypothesis about the actual evolutionary history of a group, while "phylogenies" represent true evolutionary history.
To other biologists, "cladogram" suggests that the lengths of the branches in the diagram are arbitrary, while in a "phylogeny," the branch lengths indicate the amount of character change.

24. Phylogeny vs. Cladistics
Bioinformaticians produce cladograms representing relationships between sequences, either DNA sequences or amino acid sequences. However, cladograms can rely on many types of data to show the relatedness of species.
In addition to sequence homology (existence of shared ancestry between a pair of structures, or genes, in different species) information, comparative embryology, fossil records and comparative anatomy are all examples of the types of data used to classify species into phylogenic taxa.
So, it is important to understand that the cladograms generated by bioinformatics tools are primarily based on sequence data alone.