evolution 3.6 Flashcards
what is a mutation
a mutation is a random change to genetic material, they are spontanious and the only source of new alleils
what can mutations be classified as
neutral-doesnt effect its survival
disadvantagous-gives an organism a disadvatage to other individuals
advantagous-gives an organism an advantage to other individuals
what is a mutagen
something that increases the rate of mutations
what can increase the rate of mutations
environmental factors, like radiation(uv rays) or some chemicals(mustard gas)
why is mutations importaint
for selection, because without variation no organism has an advantage over another and competition is essential for selection
what can new alleils result in
plants and animals becoming well adapted to their environment
what is an adaptation
an adaptation is an inherited characterisic that makes an organism well suited to survival in its environment
what are the types of adaptations
physiological and behaviourable
explain a physiological adaptation
an adaptation that is obvious on the outside like flippers or a shell
explain a behavourable adapatation
it includes individual and social behaviours
why natural selection happens
species produce more offspring than the environment can sustain , natural selection or survival of the fittest occurs when there is selective pressures
what are selective pressures
something that impacts on an individuals chances of survival is a selective pressure for example everything on your biotic and abiotic list is a pressure
what is natural selection
the best adapted individuals in a population survive to reproduce, passing on the favorable alliels that give the selective advantage
variation and change
if there is variation in a population there is the potential for adaptation if the conditions change.
Over time this can lead to evolution of the species, or even the formation of a new one
speciation definition
the development of a new species
