THE FOSSIL RECORDThe Rank and Order of Life

Latin binomial nomenclatureA system of binomial nomenclature is used to name organisms. The first of the two names is the genus and the second name is the

species. The genus and species names are underlined or italicized. The name of the genus is capitalized, but the name of the species is not.

Examples: Felis domesticus, the house cat

Felis leo, the African lionFelis onca, the jaguar

Canis familiaris, the dogHomo sapiens, the human

THE FOSSIL RECORDThe Rank and Order of Life

The Species

Fundamental unit of biological classification

A species is a group of organisms that have structural, functional,and developmental similarities, and that are able to interbreed and produce fertile offspring.

Doesn’t include sexual dimorphism, differences in developmentalstages and individual variation.

THE FOSSIL RECORDTaxonomy

Organisms are grouped based on similarities intotaxonomic groups or taxa (sn. taxon)

KingdomPhylum (pl. Phyla)

ClassOrder

FamilyGenus

Species

THE FOSSIL RECORDTaxonomy

Five kingdoms of organisms

Animalia (animals)Plantae (plants)Monera (blue-green algae and bacteria)Fungi (mushrooms, fungus)Protoctista (single celled organisms)

Organisms from all five Kingdoms found as fossils

THE FOSSIL RECORDTaxonomy

More recent classifications recognize threesuperkingdoms or domains based on evolutionary relationships.

Bacteria – bacteria and blue-green algae

Archaea – primitive bacteria, live underextreme conditions

Eucarya – animals, plants, fungi, protists

THE FOSSIL RECORDTaxonomy

Domain Eucarya Kingdom Animalia

Phylum Chordata Class Mammalia

Order Primates Family Hominidae

Genus Homo Species sapiens

THE FOSSIL RECORDCells

All organisms are composed of cells

Eukaryotic cells have a nucleus and organelles

Prokaryotic cells lack anucleus or organelles

Kingdom Monera only

THE FOSSIL RECORDOrganic Evolution

Evolution is change over timeOrganic evolution refers to changes in populations

THE FOSSIL RECORDLamarck’s Theory of EvolutionJean-Baptiste Lamarck 1744-1829

Organisms changed form or traits due to inner “want”Later inherited by future generationsInheritance of Acquired Traits

THE FOSSIL RECORDDarwin’s Theory of EvolutionCharles Darwin

Competition for food, shelter,living space, and sexualpartners among specieswith individual variationsand surplus reproductivecapacity will inevitablyresult in the elimination ofless well-fitted and “survivalof the fittest”, or best suitedto the environment

THE FOSSIL RECORDDarwin’s Theory of Evolution

Published On the Origin of Species by Means of Natural Selection in 1859

Jointly proposed by Alfred R. Wallace

THE FOSSIL RECORDMendelian Principles of InheritanceGregor Mendel 1822-1884

Demonstrated how traits are passed parents to offspring

Experimented with garden peas

Led to science of genetics

Mechanism of evolution

THE FOSSIL RECORDMendelian Principles of Inheritance

Chromosomes present in nucleus of cells

THE FOSSIL RECORDMendelian Principles of Inheritance

Chromosomes composed of long molecules of DNADNA = deoxyribonucleic acidDouble helix

Discovered by Watson and Crick, 1953

THE FOSSIL RECORDMendelian Principles of Inheritance

DNA carries chemically coded information fromgeneration to generation

Provides instructions for growth, development,and functioning.

THE FOSSIL RECORDReproduction and Cell Division

Reproduction in organisms may be:

Sexual

Asexual

Alternation of sexual and asexual generations

All involve division of cells

THE FOSSIL RECORDAsexual Reproduction

Asexual reproduction can occur by:

Binary fission – cells split in two (single celled)

Budding – parent sprouts an appendage that maylater separate from the parent or remainattached (colonial)

Spores – alternation of generations

Binary fission

Hydra budding

AlternationOf

Generations

THE FOSSIL RECORDCell Division - Mitosis

Division of cells of sexual organisms.

Produces new diploid cellsCells have identical chromosomes

to the parent cells

THE FOSSIL RECORDSexual Reproduction and Cell Division

Sexual reproduction allows new combination ofchromosomes to result

One member of each pair of chromosomes is inherited from each parent

Allows variability within the species

Sexual Reproduction

One diploid "parent" cell divides to produce four genetically unique "daughter" cells which will then be processed into gametes (the sex cells we usually know as "ova" and "sperm")

Requires the halving of the genetic material (DNA) in preparation for recombination with an equal amount of DNA from the same species

THE FOSSIL RECORD

Sexual Reproduction - MeiosisTHE FOSSIL RECORD

Chromosome number goes from diploid to haploid

Sexual Reproduction - MutationsTHE FOSSIL RECORD

Produce alterations in genes and DNAChanges to DNA moleculeInduced chemically or by radiation

Mutations in sex cells are passed to succeeding generations

EVOLUTION -POPULATIONS, SPECIATION AND ADAPTIVE RADIATION

Population – a group of interbreeding organisms

Gene pool – the sum of all of the genetic componentsin a population

Speciation – the origin of new species

Species – a collection of populations within which thereis free flow of genes