Chapter 18: Classification Mr. Freidhoff

Charles Darwin Species “I look at the term species, as one arbitrarily given for the sake of convenience to a set of individuals closely resembling each other.” – #YaBoy, Charles Darwin

Biological Species Concept Biological Species Concept: a population whose members can mate with one another and produce fertile offspring. – Concept has flaws – Doesn’t apply to asexual organisms. – Species that are fossilized? – Hybrids between species.

Biological Species Concept 8.7 million identified species, estimated 10 – 15 million species still unidentified.

Taxonomy The identification, naming, and classification of species. Common names sometimes create confusion, scientists use scientific names.

Misleading Common Names: Electric Eel NOT EVEN AN EEL! (fish)

Misleading Common Names: Koala Bear Marsupial, not a bear…

Misleading Common Names: Flying Fox Bat

Misleading Common Names: Mountain Chicken

The Linnaean System of Classification Carolus Linnaeus. Swedish Scientist, 1700s. Created an order of how to classify organisms in a scientific manner. Created binomial nomenclature. Link

The Linnaean System of Classification Kingdom Phylum Class Order Family Genus Species

Mnemonic Device King Phillip Came Over For Good Soup Keeping Precious Creatures Organized For Grumpy Scientists Kobe Practiced Curray’s Outside Famed Gorgeous Shot K P C O Freidhoff G Sasquatch

Binomial Nomenclature Two-name system: – First name is the organism’s genus. – Second name is the organism’s species. The first letter of the genus is ALWAYS capitalized. The first letter of the species is NEVER capitalized. Scientific names of organisms are always italicized. Homo sapiens H. sapiens Latin for “wise man”

Why use Latin for scientific names? What do the following mean: cool, hot. Meanings of word can change through usage. Latin is a “dead” language so the meanings of words won’t change.

What species are we? Kingdom Phylum Class Order Family Genus Species Animalia (multicellular, eukaryotic) Chordata (spinal cord) Mammalia (mammary glands) Primates (2 mammary glands) Hominidae (bipedalism) Homo (Human, tool using) Sapiens (Modern Humans)

Accurate scientific representation of the tree of life. Phylogenetic trees depicts relationships between species through their evolutionary history. DNA evidence supports relations between species. Phylogenic Tree

What an Evolutionary Tree Represents

Zoooooming out…

Branching pattern of four species

Human Comparison of cytochrome c mutations Molecular Phylogeny

Human Phylogenetic Tree

3 Domains of Life Archae Bacteria Eukarya

Fungi EUKARYA Trypanosomes Green algae Land plants Red algae Forams Ciliates Dinoflagellates Diatoms Animals Amoebas Cellular slime molds Leishmania Euglena Green nonsulfur bacteria Thermophiles Halophiles Methanobacterium Sulfolobus ARCHAEA COMMON ANCESTOR OF ALL LIFE BACTERIA (Plastids, including chloroplasts) Green sulfur bacteria (Mitochondrion) Cyanobacteria Chlamydia Spirochetes

6 Kingdoms of Life Archaebacteria Eubacteria Protista Fungi Plantae Animalia Link

Domains to Kingdoms

Archaebacteria

Eubacteria streptococcus spirillum bacillus

Protista parameciumVolvox algae amoeba diatoms euglena kelp

Fungi Shiitake mushrooms bracket fungi giant puffball corn smut

Plantae moss fern cycad white pinerose strawberry

Animalia

Mass Extinctions Sharp decrease in the number of species in a relatively short period of time. There have been 5 Mass Extinctions that have occurred since the earth formed. We are on the verge of a 6 th mass extinction due to humans.

Mr. Freidhoff’s Dogma of Biology Life → Genetics → Mutation → Evolution

Speciation Origin of New Species. Process of how new species evolve. There are several factors that affect how fast or slow new species evolve:

Time Similar species have mating times that are different Western Spotted Skunk Eastern Spotted Skunk

Habitat Location or habitat is different. Species that live in different habitats can’t reproduce.

Reproduction Barriers Different number of chromosomes Reproductive organs not contusive Bat  Mouse 

Behavior Two similar species may have different courtship or mating behaviors. Courtship rituals differ

2 Different Kinds of Speciation Allopatric Speciation Sympatric Speciation

Allopatric Speciation Geographic separation Reproductive isolation Populations become genetically different

Sympatric Speciation Populations not geographically separated Can be due to rapid genetic changes: – Alter morphology – Alter behavior – Alter habitat preferences

Tempo of Speciation Gradual Speciation – Small changes in environment/Genetic drift Tempo of new species being create is different for each species and location Punctuated speciation – Environments change quickly, then remain stable – Geographical and rapid morphologic change

Punctuated Equilibrium Model Link