Topics: Taxonomy, Kingdoms and Evolution

2007

TEK 7A

• Identify characteristics of kingdoms including archeabacteria, eubacteria, protist, fungi, plants and animals

• Taxonomy is the method used by scientists to categorize and name living things.

• We give all organisms a scientific name which is 2 names.

• Scientific names are in Latin, written in italics or underlined and the first name is capitalized and the second name is lower case.

• EX: Canis familiaris (dog)

• We sort organisms into large categories and further sort them into smaller and smaller categories, getting more specific as we go.

• The more categories two organisms share the more closely related they are:

• Classification system is hierarchical…goes from large to small

Domain Kingdom PhylumClassOrderFamilyGenusSpecies

• Note!!! The genus and species are the 2 names of the scientific name

Which are closely related, which is most distantly related?

Organism family genus species

Panthera leo (lion) Carnivora Panthera leo

Equus caballus (horse)

Equidae Equus caballus

Panthera tigris (tiger)

Carnivora Panthera tigris

Felis domestica (cat)

Carnivora Felis domestica

Canis familiaris (dog)

Carnivora Canis familiaris

• Kingdom is the largest category. • There are 6 Kingdoms:

– Archeabacteria– Eubacteria– Protist – Fungi– Plants– Animals.

• Prokaryotic (no nuclear membrane)

• Single celled

• Lives only in harsh environments (deep sea, volcanic vents, boiling water.)

• Prokaryotic (no nuclear membrane

• Single celled• Found just about

everywhere on earth (including inside you and on your skin.)

• Many are decomposers, some are parasitic and some are photsynthetic

• Eukaryotic (has a nuclear membrane)

• Most are single celled• Most live in water• Some are heterotrophs,

some are autotrophs, some are parasitic

seaweed

algae

amoeba

paramecia

euglena

• Eukaryotic (has a nuclear membrane)

• Most are multi celled• All are heterotrophs• Fungi cannot move

Athlete’s foot

Bread moldmushroom

• Eukaryotic (has a nuclear membrane)

• All are multi celled• All are autotrophs• Plants cannot move

• Eukaryotic (has a nuclear membrane)

• All are multi celled• All are heterotrophs• Animals can move

Unicellular eukaryotes that are usually mobile and obtain food from other organisms

probably belong to the kingdom --

• A. Plantae

• B. Fungi

• C. Animalia

• D. Protista

TEKS 7A

• Identify evidence of change in species using fossils, DNA sequences, anatomical similarities, physiological similarities and embryology

TEKS 7B

• Illustrate the results of natural selection in speciation, diversity, phylogeny, adaptation behavior and extinction

• Evolution - Gradual change in the genetic makeup of a species over a long period of time

Natural Selection• Also called “Survival of the

Fittest”• Organisms best suited for an

environment live to pass that trait on

1. Too many offspring are produced2. Environment is harsh (resources limited)3. Offspring variations…some have

variations that help them4. The ones with helpful variations will

live 5. The ones that live pass their helpful

variations on to their offspring6. The overall population changes as the

individuals with the helpful variations increase in number.

Let’s look at a frog for a good example!

1. A 1000 frogs are hatched2. There are only 800 flies and each frog

needs 2 flies to survive3. Some frogs have sticky tongues, most

do not.4. The frogs with the sticky tongues catch

the flies and live5. They have offspring which all have

sticky tongues.6. The population will eventually have all

sticky-tongued frogs.

Let’s look at a frog for a good example!

• Five major points that we use to support the theory of evolution:

1.Fossil Record 2.Homologous Structures3.Vestigial Organs4.Amino Acid sequences5.Embryology

Fossil RecordFossil RecordEvolution can be

seen in the fossil record.

Darwin predicted and we have found thousands of “transitional forms” that link ancestors and current organisms.

•

Homologous StructuresHomologous Structures• Structures that are

similar in more than one species

• Used to support a common ancestry.

• Example: Common mammal forearm / leg / flipper.

Vestigial StructuresVestigial Structures

• Parts that are reduced in size and seem to have little or no function.

• Vestigial structures are considered to be evidence of an organism’s evolutionary past

• ex: Whale’s pelvic bone, blind salamander eye socket, our appendix, our wisdom teeth.

EmbryologyEmbryology• All vertebrate embryos

have similar structures. • All have a tail, buds that

become limbs and pharyngeal pouches.

• We lose the tail. Mammals, birds and reptiles lose the pharyngeal pouches…in fish and amphibians they become gills

DNA sequencesDNA sequences • All DNA consists of

nitrogen bases: T, A, C, G arranged in thousands of different sequences

• The closer two organisms are related to each other, the more their DNA sequences are the same.