Species and taxonomy Flashcards
Define species
- Group of organisms that share a large number of common characteristics and can interbreed and produce fertile offspring
What does a phylogenetic classification system do?
- arrange species into groups based on their evolutionary origins and relationships
What are homologous characteristics?
- similar characteristics resulting from common
ancestor
What is a phylogenetic tree?
- graphical representation of evolutionary relationships between organisms
What two types of evidence do evolutionary investigations focus on?
- Morphologic (forms and function)
- Genetic
What do molecular characters assume?
- the more similar the DNA sequences are in two organisms, the more closely related they are
What do molecular characters assume?
- the more similar the DNA sequences are in two organisms, the more closely related they are
What can the number of conserved genes be used to show?
- evolutionary relationships between organisms
What is a hierarchy?
- smaller groups are placed within larger groups, with no overlap between groups
What is each group in a phylogenetic classification system called?
- taxon
What is the hierarchy composed of?
- domain
- kingdom
- phylum
- class
- order
- family
- genus
- species
What is each species universally identified by?
- a binomial
What does a binomial consist of?
- genus and species
What can clarify evolutionary relationships between organisms?
- immunology
- genome sequencing
What are the three domains of life?
- Bacteria
- Archaea
- Eukarya
What is courtship behaviour essential for?
- successful mating and for species recognition
What are courtship rituals?
- a sequence of actions which is unique to each species
What can courtship rituals include?
- sequence of dance moves
- sounds
- release of pheromones
- display of colourful feathers
- fighting
What is the importance of courtship?
- Ensure successful reproduction
- Ensure survival of the offspring
How does courtship ensure successful reproduction?
- enables them to recognise own species and opposite sex
- synchronises mating behaviour- indicates sexually mature and in season (releasing egg)
How does courtship ensure survival of the offspring?
- form a pair bond
- choose a strong and healthy mate
How do courtship rituals indicate how closely related a species are?
- courtship rituals are genetically determined so the more similar a courtship sequence is between different species, the most closely related the species are
- the more similar their DNA base sequence is
What is the advantage of the binomial system?
- same genus shows close relationship
Why do different species look similar?
- Live in similar environment
- Have similar selection pressures
- Similar alleles will have the selective advantage
- Produces similar/same proteins and therefore have similar characteristics
Why use a classification system?
- understand relationships between organisms and keep track of changes
- system used needs to be universal
- system based on putting organisms into groups
