Organisms and evolution - 1 Flashcards
what three considerations must be made when doing field work?
- terrain
- weather conditions
- isolation
give some examples of sampling techniques
- scat sampling
- transects
- point counts
- remote detection
- quadrats
- camera traps
what three things should sampling be?
- random
- stratified
- systematic
what is a point count used for?
used for determining species abundance
what is a transect used for?
used for deterring changes in community
why would remote detection be used?
used for areas that are difficult to access
what sampling techniques are used for elusive species?
- camera traps
- scat sampling
what is systematic sampling?
samples are taken at fixed intervals
what is stratified sampling?
population is split into sub-populations
what is used to estimate population size?
mark and recapture
what are some methods of marking?
- banding
- collar
- tagging
- surgical implantation
- painting
- fur/hair clipping
what three assumptions are made when estimating population size?
- all individuals have an equal chance of recapture
- marking doesn’t affect survival or behaviour
- there is no emigration of marked individuals nor immigration of other individuals
what equation is used to estimate a population size?
N = MC/R
how can organisms be identified?
- classification guides
- biological keys
- analysis of DNA or protein
what is taxonomy?
defining groups of biological organisms on the basis of shared characteristics and giving names to those groups
what is a model organism?
the best studies species within a taxonomic group
what is an advantage of using a model organism?
other species may be more difficult to study
what are the three domains of life?
bacteria, archaea and eukaryote
what are the four phyla in the plant kingdom?
- mosses and liverworts
- ferns
- gymnosperms
- angiosperms
what are the 5 divisions in the animal kingdom?
- chordata
- arthropoda
- Nematoda
- Platyhelminthes
- Mollusca
what does genetic evidence reveal?
reveals relatedness obscured by divergent or convergent evolution
what is divergent evolution ?
development of differing life forms from a common origin
what does divergent evolution result in?
results in closely related life forms with very different phenotypes
when does divergent evolution occur?
occurs when different selection pressures are acting on each lineage
what is convergent evolution?
separate evolution of similar phenotypic adaptations in lineages whose ancestors did not share these adaptations
when does convergent evolution occur?
occurs when very similar selection pressures are acting on these unrelated lineages
what is a cladogram?
branching, tree-like diagram used to show phylogenetic relationships
what is the study of animal behaviour called?
ethology
what causes animal behaviour?
- genetics
- external environment
- internal environment
what is an ethogram?
a comprehensive list/description of all the behaviours of an organism
what is ab libitum sampling?
observer records key behaviours whenever they occur
what is continuous sampling?
all occurrences of behaviour are recorded when they start and stop
what is point/instantaneous sampling?
behaviour is sampled periodically at regular intervals
when studying animals what is it important not to do?
not to use anthropomorphism (human characteristics)
what is evolution?
the change over time in the proportion of individuals in a population differing in one or more inherited traits
what can cause evolution?
- genetic drift
- natural selection
- sexual selection
what is natural selection?
non-random increase in frequency of DNA sequences that increase survival
what is sexual selection?
non-random increase in the frequency of alleles that make mating and reproduction more likely
what is genetic drift?
the random change in allele frequency
will genetic drift have the greatest effect in small or large populations?
small populations
give two examples of genetic drift
founder effect and bottleneck effect
what arises as a result of a mutation?
variation
what are the three modes of selection?
- stabilising
- directional
- disruptive
what is absolute fitness?
ratio of frequencies of a particular genotype from one generation to the next
what is relative fitness?
the ratio of serving offspring of one genotype compared with other genotypes
how is absolute fitness calculated?
absolute fitness = n of F1 generation / previous generation
how is relative fitness calculated?
relative fitness = absolute fitness of genotype (x) / absolute fitness of most successful genotype
what does high selection pressure cause?
a rapid rate of evolution
what can increase the rate of evolution?
- shorter genration times
- warmer environments
- sharing of beneficial DNA sequences between different lineages through sexual reproduction
- horizontal gene transfer
what is co-evolution?
a change in traits of one species that acts as a selection pressure on the other species
what is the Red Queen hypothesis?
co-evolutionary arms race between a parasite and host. both organisms must ‘keep running in order to stay alive’
