Lecture 1 Zoology

Species

fundamental unit of biology

Species are essential for:

• Evolutionary biology

• Conservation and government protection

• Zoos and aquariums

Evolutionary biology

understanding how populations change and diversify

Conservation and government protection

protecting endangered species

Zoos and aquariums

managing and breeding animals correctly

Carl Linnaeus (1735) did what?

developed the binomial system for naming specie

Binomial

Two names

• Genus

• Species

Genus

capitalized, groups closely related species

Species (Naming)

• specific epithet

• lowercase, identifies the species within the genus

what is the Why it’s useful

• Replaced older, long and confusing descriptive names.

• Scientific (Latin) names are universal → scientists worldwide use the same name.

• Common names vary by language and region, so scientific names avoid confusion

Determining a new species:

• Is this species truly new and different from the ~1.3 million already described?

• If it is, the species can be formally recognized once published and accepted by other taxonomists.

What a published species description includes

• Description of differences → How the new species differs from existing species.

• Name of species → Follows rules set by the International Code of Zoological Nomenclature (ICZN).

• Type specimen → A physical example of the species is designated as a reference.

You can name species after:

Places

People

Descriptions of it

Albus

White

Brevi

Short

Cauda

Tail

Fuscus

Dark Brown

Minor

Small

Major

Large

Occidentalis

Western

Sinensis

Chinese

What is a Biological Species Concept (BSC)?

• A species is a group of actually or potentially interbreeding populations that are reproductively isolated from other such groups.

• Focuses on reproductive capability rather than just physical similarity.

Advantages of BSC

-Focused on weather group of organisms can reproduce with each other and explain why

-Widely used and easy to apply for animals that reproduce sexually

Disadvantages of BSC

-doesnt work for asxual organisms

-hard to apply to extinct species

-sometimes populations that could interbreed naturally dont

What is a species (Morphological Concept)?

A species is a group of organisms that look alike (share similar physical traits) and are distinct from other groups.

Focuses on observable traits rather than reproductive capability.

Morphological (or Phenetic) Species Concept Advantages

• an be applied to asexual organisms and fossils (where reproduction cannot be observed).

• Easy to use because it relies on visible traits.

Morphological (or Phenetic) Species Concept Disadvantages

Looks can be misleading some very different species look alive

-individuals of same species can look different, causing confusion

What is a Phylogenetic Species Concept (PSC)?

A species is the smallest group of organisms that share a common ancestor and can be distinguished from other such groups.

Focuses on evolutionary history and ancestry, not just reproduction or appearance.

Phylogenetic Species Concept (PSC) Advantages

• Can be applied to sexual and asexual organisms.

• Works for living species and fossils (as long as traits can be compared).

• Reflects true evolutionary relationships using genetics or morphology.

Phylogenetic Species Concept (PSC) Disadvantages

• Requires detailed phylogenetic data (molecular or morphological).

• Can split populations into many tiny species if small differences are considered significant.

• May be more complex and harder to apply than simpler concepts.

Hierarchically

Classification organizes organisms,from general to specific, based on shared traits and evolutionary relationships, with modern taxonomy emphasizing phylogeny