4.3:Evolution + Classification Flashcards
What are the four purposes of classification?
- Identify new species
- Study evolutionary relationships
- Understand shared traits and adapadations
- Share research globally to identify links with organisms on other continents
What is the linnaean classification?
- (Domain)
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
What are the three domains?
Archaea, eubacteria, eukarya
What are the features of the domain bacteria?
- Contains the kingdom eubacteria only, found in all environments
- Prokaryotic unicellular organisms
- Distinct cell membrane lipids
- Have peptidoglycan in cell wall
- Unique RNA polymerase enzyme
What are the features of the domain archea?
- Contains the kingdom archea only, typically found in extreme environments
- Prokaryotic unicellular organisms
- Have histones so gene and protein synthesis is more similar to eukarya then bacteria
- No peptidoglycan in cell walls
- Different cell membranes that contain fatty acids bound to glycerol by ether linkages
What are the features of the domain eukarya?
- Contains four kingdoms from the five kingdom system: Animalia, plantea, fungi, prototicsta
- All have nuclei and membrane bound organelles
How is bacteria different to eukaryotes and archaea?
- Different cell membrane structure
- Flagella with a different internal structure
- Different enzymes (RNA polymerase) for synthesising RNA
- No proteins bound to their genetic material
- Different mechanisms for DNA replication and for synthesising RNA
What features do archaea share with eukaryotes?
- Similar enzymes (RNA polymerase) for synthesising RNA
- Similar mechanisms for DNA replication and synthesising RNA
- Production of some proteins that bind to their DNA
What are the five kingdoms?
Prokaryota
Fungi
Plantea
Anamalia
Protista
What is autotrophic?
Gain nutrients by doing photosynthesis
What is heterotrophic
Gain nutrients by digesting and absorbing food
What is saprophytic?
Feeding on decaying matter
What are reasons for classification?
- Identify species
- Predict characteristics of certain organisms we have
- Find evolutionary links
What is artificial classification?
- Based on only a few characteristis
- Does not reflect any evolutionary relationships
- Provides limited information
- Is stable
What is natural classification?
- Uses many characteristics
- Reflects evolutionary relationships
- Provides a lot of useful information
What is phylogeny?
Evolutionary relationships between organisms
What is a phylogeny tree?
Is used to show evolutionary links
- Shows evolutionary timeline
- Continuous
What is a disadvantage of early classification?
Relied on only visible features
What is evidence for evolution?
Paleontology
Comparative anatomy
Comparative biochemistry
What is paleontology and how can we use it as evidence for evolution?
Problems as well
Study of fossils
- Compare them to see if there are any similarities or differences
- Simple life forms evolved into more complex ones
- Find how closely related organisms might be based on similarities/differences in their structure
Problem: - Incomplete fossil record
What is comparative biochemistry and how do we use it as evidence for evolution?
There is a protein called cytochrome c which is involved in respiration
They look at amino acid sequence fpr cytochrome C from different organisms and look at any similarities or differences
- Organisms that are closely related would have very similar or the same amino acid sequence
What are the types of variation?
- Interspecific - Variation between species
- Intraspecific - Variation within species
- Continuous - Numerical (height), use line graph
- Discontinuous - categoric data (eye colour), use bar chart
What are causes of variation?
Genetics:
- Alleles - dominant, recessive
- Mutations
- Meiosis - Crossing over (P1), independent assortment (Homologous chromosomes/Bivalent) (M1) + (Chromatids (M2)
- Random fertilisation
Environment
What are the three different types of adaptations?
Behavioural:
- Activities and responses, whether inherited or learned
Anatomical:
- Physical structures, both internal and external
Physicological:
- Internal biological functions
What are four examples of anatomical adaptations?
- Body coverings - fur, feathers, scales protect organisms and support their survival
- Camouflage - organisms with colouration that blends into their environment are less likely to be detected
- Mimicry - some species imitate the appearance of more dangerous ones for protection
- Teeth - the shape of an animal’s teeth are adapted to its diet
What are three examples of behavioural adaptations?
- Defensive responses - for example, opossums play dead and rabbits freeze to avoid detection by predation
- Courtship - for example, male scorpions dance to attract mates
- Seasonal actions - migration helps access resources year - round and hibernation helps bears conserve energy when food is scarce
What are three examples of physiological adaptations?
- Venom - used by snakes to immobilise prey and by planys to deter herbivores
- Antibodies - produced by bacteria to outcompete rival species
- Water storage - desert grass can survive for a year without water source by storing water in their bodies
What is divergent evolution?
Two species have evolved from the same common ancestor
What is convergent evolution?
Two species share similar adaptations in the same habitat but have different evolutionary origin
How can anatomical adaptations provide evidence for evolution?
Homologous structure - appear different on the outside but have a similar underlying structure
Evidence for divergent evolution
Analogous structure - similar appearances and function but have different underlying structure and different origin
Evidence for convergent evolution
What did Darwin do?
Discovered that what appeared to be a wide range of bird species were actually all closely related species
Speices had arrived on the islands from the mainland and had then evolved to form many different species
What did Wallace do?
Independently came ot the same conclusions as Darwin. Made collections in both the American and in south east Africa
What were Darwin’s conclusions? (summarised)
3x
- There is a struggle to survive
- Better adapted individuals survive and pass on their characteristics
- Over time, a number of changes may give rise to a new species
What are selection pressures?
Environmental factors that affect their survival and reproduction
What are three selection pressures?
Predation
Competition for resources
Disease
What is the proccess of natural selection?
- There is variation in characteristics within a species
- More genetic variation emerges within a population due to random mutations
- Individuals with alleles that code for traits that are advantageous for survival are more likely to reproduce
- These advantageous alleles are passed down to offspring
- Over time, these beneficial alleles became more common in the population
How do pest resistant insects come about?
- Some insects develop random mutations that provide resistance to antibodies
- When antibiotics are used, only the resistant bacteria survive, while the others die off
- The resistant bacteria reproduce, passing on resistant alleles to their offspring
- Over time, the production of resistant alleles increase, leading to mostly resistant bacteria
What is a student’s t test?
Statistical test used to determine if there is a significant difference between the mean values of a particular variable across two populations
What are the conditions of a t test?
- Data must be continuous and normally distributed
- The variances of the population be equal
- The samples must be independent of each other
What is spearman’s rank correlation coefficient?
Measure the strength and direction of association between two continuous variables that are not normally distributed
What is natural selection?
Used to explain how features of the environment apply a selective force on the reproduction of individuals in a population
