Adaption & Variation Flashcards
what is adaptation
can be physiological, behavioural & anatomical and can result of an animals lifestyle diet or environment
whats physiological adaptation
its in an animals body processes, e.g, snakes are physiologically adapted to produce venom which they use against predators
whats anatomical adaptation
in animals shape & structure, e.g., bat forelimb adapted to form wings - improve access to suitable foods
whats behavioural adaptation
in animals languages tool use & survival strategies. e.g., migration in birds to avoid harsh environments
whats variation
differences between organisms, includes diet, behaviour, aesthetics
what is variation linked to
differences or changes in dna - variations can be passed down from parents to offspring due to this
define evolution
a change in characteristics over several generations
define speciation
formation of new species as part of evolutionary process
what is advantageous variation
where animals have an advantage over other animals - more likely to survive & reproduce
how does advantageous variation affect reproduction
variation = heritable - offspring likely to have advantageous feature which increases their chances of survival (NATURAL SELECTION)
how does speciation occur
over time it can lead to evolution of the species, if animals in a species develop different advantageous variation it could lead to them splitting into 2 groups (speciation)
what are the different types of selection pressures that affect variation
stabilising, directional, diversifying/disruptive
how does stabilising affect variation
reduces the variation between animals DNA - extreme phenotypes are reduced & proportion of animals with average phenotype are increased
how does directional affect variation
encourages a particular new phenotype usually in response to environmental changes
how does diversifying affect variation
increases variation between animals DNA, extreme phenotypes become more common & average ones are reduced
