ME - Species, Individual, & Sex - Exam 2

What is the Biological Species Concept?

Species are groups of organisms that can sexually reproduce and produce viable offspring.

What are problems with the Biological Species Concept?

Doesn’t apply to asexual species, fossils, juveniles, hybrids, or cryptic species.

What is the Morphological Species Concept?

Species are defined by physical traits; used often for fossils.

What is the Phylogenetic Species Concept?

Defines species based on evolutionary relationships in a phylogeny.

What does gene flow measure?

Genetic connectivity between individuals, populations, or species.

What are OTUs?

Operational Taxonomic Units — used to represent evolutionary units.

Which markers are best for studying species?

AFLPs and Microsatellites.

Which marker should not be used for species ID?

RAPD — low accuracy due to random selection.

Why isn’t gene sequencing commonly used for species ID?

Accurate but expensive and impractical.

What are the three koala subspecies?

Queensland (P. c. adustus), New South Wales (P. c. cinereus), and Victorian (P. c. victor).

How do koala subspecies differ?

By fur color/thickness, body size, and skull shape.

Describe the Victorian koala.

Large (12 kg ♂), dark grey fur with chocolate highlights and fluffy ears.

Describe the Queensland koala.

Smaller (6.5 kg ♂), lighter scruffy fur.

Describe the New South Wales koala.

Slight golden tinge to fur.

What is the koala’s conservation status?

IUCN

What are major threats to koalas?

Habitat loss, wildfire, climate change, chlamydia infection, historical hunting.

What does genetic evidence show about koala populations?

RAPDs, mtDNA, and microsatellites suggest one population with north/south variation.

Why use RAPDs in juvenile forms?

To quickly ID species (e.g., tadpoles) for habitat management.

How are genetic markers used in forensics?

To determine if maggots or remains belong to different populations → may show body movement.

What markers are used to study hybrids?

Separate maternal and paternal markers (e.g., mitochondrial for animals).

What is DNA barcoding?

Using a specific DNA sequence to identify species.

Is a universal DNA barcode for all life possible?

Not yet; feasible for some groups like birds (93.6%) and fish (97.5%).

What are cryptic species?

Distinct species classified as one due to similar appearance or secretive behavior.

What is metabarcoding?

Identifying multiple species from mixed environmental samples (e.g., pollen, feces).

What is metagenomics?

DNA analysis without PCR; uses universal primers to detect unknown sequences.

What is eDNA?

Environmental DNA used to detect species presence in a habitat.

What are the two types of speciation?

Anagenesis (one species evolves over time) and Cladogenesis (one splits into two).

What is allopatric vs sympatric speciation?

Allopatric = geographic isolation; Sympatric = within same area.

What are hybrids?

Crosses between species; may form hybrid zones; can cause issues like introgression.

What is the barcoding gap?

Genetic variation is greater within species than between species—causing misidentification.

How do we define an individual genetically?

Using variable markers (microsatellites) and the Probability of Identity (PI).

What does PI measure?

The likelihood two individuals share the same genotype by chance.

How can you identify sex genetically?

Detect sex chromosomes or genes/proteins coded on them.