Species Concept Flashcards
Taxonomy
What is the view on species?
There is typological Vs populational (Evolutionary) thinking.
The populational view of thinking is now widely accepted.
What is the biological species concept (BSC)
A species is “A group of actually or potentially interbreeding individuals”
This leads to controversy between the allopatric and sympatric speciation theories.
Testing these theories can be difficult.
What is the phylogenetic species concept?
The smaller diagnosable cluster of individual organisms within which there is a parental pattern of ancestry and descent.
Give examples of other less-used species concepts.
Ecological species concept- A species is a lineage that occupies an adaptive zone and evolves separately from all other lineages outside its range.
Recognition of species concept - Species is a field for reproduction.
Cohesion species - The most inclusive population of individuals having the potential for phenotypic cohesion through intrinsic cohesion mechanisms.
How do species concepts affect conservation?
There is a focus on the Biological species concept that can ignore populations and ecological function.
By adopting a Phylogenetic Species concept this can increase the number of species.
Why is attention to species still useful?
Identified entities can be used for legal attention and facilitate assessment.
By the public recognising species this can help with engagement.
What is an umbrella species concept?
A species whose conservation is expected to confer protection to a large number of other species. These tend to be larger charismatic species (E.g., Giant Pandas)
They can also be referred to as a beneficiary species.
What is the primary aim of taxonomy?
To name, circumscribe, describe, and classify species.
What is phylogeny?
The pattern of evolutionary relationships.
Why is taxonomy in crisis?
The crisis of biodiversity has led to the development of ‘Conservation biology’ which has resulted in a taxonomic crisis;
- Not enough funding
- Museums regarded as old fashioned
- Bias to other areas of academic research.
- Taxonomy is bad at marketing itself.
How can phylogeny be inferred?
Based on phenotypes or genotypes.
What is maximum parsimony (MP)
Selects the tree with the least number of evolutionary changes
Works best for relatively similar sequences and small number of sequences.
What is Maximum likelihood when it comes to drawing phylogenetic trees?
Looks for the tree with maximum probability.
Unlike parsimony considers all trees.
What are the three main weaknesses of DNA-based taxonomy?
mtDNA/ chloroplasts may not represent a species’ complete evolutionary history.
The rate of genetic change may be slower than the speciation rate - which underestimates species richness.
May overestimate species richness.
What is integrative taxonomy?
Combining multiple approaches to test species hypothesis, approaches can be genetics, behavior, phenotype, etc.
Followed by two approaches-
Integration by accumulation - May overestimate species (not strict enough)
Integration by congruence- High confidence in the validity of species but may be strict in some cases.
