Classifying Life's Diversity: Species Concepts, Taxonomy, and Phylogenetics

Why is it important to identify species?

Farmers and gardeners need to know if anything may be harmful to their crops, doctors need to identify bacterial strains for treatment, and border officials aim to prevent the entrance of invasive species.

What are the three species concepts discussed?

Morphological species concept, Biological species concept, and Phylogenetic species concept.

What does the morphological species concept focus on?

It focuses on the comparison of organisms based on their morphology, including body shape, size, and structural features.

What is an advantage of the morphological species concept?

it is simple and plain

What is a disadvantage of the morphological species concept?

How much variation is too much? Most populations are made up of non identical people

What is the biological species concept?

Similar characteristics, ability of inbreeding, produce viable offspring with its own species

What is a major advantage of the biological species concept?

It is widely used and defines species based on the ability to produce viable offspring.

What is a disadvantage of the biological species concept?

It cannot be applied to all cases, such as fossils, asexually reproducing organisms, and physically separate populations.

What does the phylogenetic species concept emphasize?

It emphasizes the evolutionary history of organisms and identifies species as distinct clusters based on genetic similarities.

What is an advantage of the phylogenetic species concept?

dna analysis - accurate, can also be used with extinct species

What is a disadvantage of the phylogenetic species concept?

evolutionary history is not known for all species

What is binomial nomenclature?

A system for naming organisms developed by Carolus Linnaeus, consisting of a genus name and a species name.

What are the rules for writing scientific names in binomial nomenclature?

The first word (genus) is capitalized, the second word (species) is lowercase, and both must be italicized or underlined when handwritten.

What are the taxonomic ranks in classification?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

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What are the taxonomic ranks for Panthers?

Domain: Eukarya, Kingdom: Animalia, Phylum: Chordata, Class: Mammalia, Order: Carnivora, Family: Felidae, Genus: Panthera, Species: Panther.

What types of evidence are used to determine relationships between species?

Anatomical, physiological, and DNA evidence.

What does anatomical evidence reveal about species relationships?

It shows structural similarities among organisms, indicating evolutionary relationships despite differences in appearance.

What is physiological evidence of relationships?

It involves comparing the physical and chemical functions of organisms, such as protein synthesis, to determine genetic similarity.

How is DNA evidence used to establish relationships between species?

By comparing DNA sequences from different species to assess their genetic similarities and differences.

What is a phylogenetic tree?

A diagram that represents hypotheses about the evolutionary relationships among species, grouping them into clades.

What is a clade?

A group consisting of a single common ancestor and all its descendants.

How do you read phylogenetic trees?

Species at the bottom of the tree are older than those at the top.

What is the importance of classification in biology?

It aids in the discovery of new drugs, tracing disease transmission, increasing crop resistance, and environmental conservation.

Taxonomic ranks

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- Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Domain

Highest level of biological taxonomy has the greatest number of species.

Three Domains

Bacteria, Archaea, Eukarya

The six kingdoms

Used to be only two

Bacteria, Archaea, Protista, Fungi, Plantae, Animalia (All Eukarya)

Autotroph

An organism that obtains energy from the sun

Photosynthesis, makes its own food

Heterotroph

Organisms that cannot make their own food

Gets nutrients from eating other organisms

Unicellular

A single celled organism

Multicellular

Consisting of many cells

Cell types

Prokaryotic and Eukaryotic

Dichotomous Key

Narrows down the identification

Of a specimen one step at a time

Virus

• Structure - dna or rna surrounded by protective coat

• not classified in any of th three domains: bacteria, archaea, eukarya

  • no traits in common

• Acellular

How are viruses different

Can’t live without cells. Must inva