Classification And Evolution Flashcards
(26 cards)
What is the purpose of classification?
Allows scientists to identify new species, study evolutionary relationships, understand shared traits and adaptations
What are the taxonomic ranks?
Domain, Kingdom, Phylum, Class, Order, family, genus, species
How do binomial names work?
The genus has upper case letter and species follows e.g homo sapiens
What are the 5 kingdoms?
Plantae, animalia, prokaryotae, Protoctista, fungi
What are the three domains?
Bacteria, archaea, Eukarya
What are the advantages of phylogenetic classification?
It produces a continues tree that doesn’t force organisms into specific taxonomic groups where they dont fit
No overlaps between groups produced
What does modern taxonomy use for evidnce to determine phylogeny?
Molecular comparison - between DNA and amino acids in proteins
Developmental studies - comparisons of embryonic similarities and differences
Anatomical examination - comparisons of similarities in physical characteristics
Behvaiour analysis - comparisons of similarities and differences of behaviour
Who proposed theory of evolution by natural selection?
Darwin adn wallace
What evidnce do we have from fossil record that supports evolution?
- simple bacteria and algae fossils are found in oldest rocks progressing to more complex vertebrates in new rocks
- plant fossils appear before those of animals that feed on these plants, indication natural order of evolution
Why is the fossil record incomplete?
Many organism decompose before they can fossilise
Fossilisation is uncommon and requires specific conditions for an organism to be preserved
Many fossils are lost due to erosion or geological processes
How does comparative anatomy provide evidnce or evolution?
Homologous structures are physical features in different species that have a similar underlying structure but may serve different functions.
Organism that share homologous structures are likely to have evolved from a common ancestor
Homologous structures are evidnce for divergent evolution where organism evolve different adaptive traits as they occupy new niches
What’s is the hypothesis of neutral evolution?
It states that most variability in a molecules structure does not affect its function
Why is the hypothesis of neutral evolution useful?
‘Neutral’ changes that don’t affect function accumulate at a fairly regular rate as they are not affected by natural selection
Comparing the rates of neutral substitions in the molecular sequences of different species lets scientist estimate when two species diverged from the common ancestor
A greater number of differences indicates earlier divergence
What are genetic factors that cause variation?
- Mutations - changes to genes and chromosomes
- Meiosis - a new combination of alleles by independent assortment of chromosomes and crossing over between chromatids
- Random fertilisation - produce new combinations of alleles in a zygote
- Random mating
What environmental factors cause variation?
Light, nutrient and food availability, tempurature, rainfall, soil conditions, pH
What are polygenes?
Different genes at different loci that all contribute to a particular aspect of phenotype, the individual effect are too small to observe but act8ing together they can make observable variation
Combined effect of multiple genes is common in continuous variation
What’s the difference between continuous and discontinuous variation?
Continuous - range of values between two extremes without distinct categories, produce a spectrum. Typically affected by both genes and environment
Discontinuous - clear, distinct categories with no intermediates, typically cause by genes
What is the t test used for?
Determine if there is a significant difference between teh mean value of a paticular variable across two populations
What are teh conditions for using a t-test?
Data must be continuous and normally distributed
Variances (standard deviation squared) of population should be equal
Samples must be independent of eachother
When in spearman’s rank used?
Used to measure teh strength and direction of association between two continuous variables that are not normally distributed
What are the three adaptations categories?
Anatomical - physical structures e.g body covering suchas fur, camouflage, mimicry, teeth
Behavioural - activities and responses e.g defensive responses like playing dead, seasonal actions like migration
Physiological - internal biological function e.g venom, antibiotics, water storage
What are analogous adaptations?
Structures that serve similar functions but originate from different evolutionary paths e.g dolphins and sharks both have dorsal fins but distant evolutionary lineages
What is convergent evolution?
When unrelated species develop similar traits as tge adapt to similar environamnetl challenges
What are selection pressures?
Environmental factors that affect their survival and reproduction. Such as:
Predation
Competition for resources
Climate change
Disease
