Lesson 1 - Evolution and adaptation Flashcards
meaning natural selection
the process by which the organisms that are best adapted in a particular environment are most likely to survive and reproduce, passing on their advantageous alleles to their offspring
meaning genotype
the genetic make-up of an organism with respect to a particular feature
meaning phenotype
the physical traits expressed as a result of the interactions of the genotype with the environment
meaning allele
a version of a gene
meaning ecology
the study of the interactions of organisms with each other and with the environment in which they live
meaning niche
the role of an organism within the habitat in which it lives
meaning anatomical adaptation
an adaptation involving the form and structure of an organism
meaning physiological adaptation
an adaptation involving the way the body of the organism works, including differences in biochemical pathways or enzymes
meaning behavioural adaptation
an adaptation involving programmed or instinctive behaviour making organisms better adapted for survival
what are the 4 main ideas that Darwin put forward
- Living organisms that reproduce sexually show great variety in their appearance
- Organisms produce an excess of offspring, so there’s always a struggle for survival, and a competition between members of the same species
- Organisms that inherit characteristics that give them an advantage in this struggle are most likely to survive and pass on their desired feature to their offspring
- Organisms that inherit characteristics that put them at a disadvantage will be more likely to die out before they can reproduce
what may cause variation of natural selecion
sexual reproduction, random mutation, interbreeding or hybridisation
what is the difference between natural selection and evolution
natural selection is the process by which evolution occurs, but natural selection may not necessarily lead to the evolution of a new species
what are the 2 types of adaptations of the grayling butterfly
- anatomical adaptation: the bottom of their wings is camouflaged against coastal heathlands & become invisible when they land
- behavioural adaptation: to avoid predators seeing their shadows on sunny days, the butterflies change their orientation through the days so that their shadow is as small as possible
How do the behavioural adaptations of cormorants in Greenland help them to survive in their cold-water, fish-eating niche
cormorants in Greenland spend less time in water, spend less time swimming on the surface of the water between dives, and return to land more often, compared to cormorants in Normandy. Thus, prey capture rates in Greenland are much higher because the changes in their behaviour result in far greater efficiency at finding food
how do changes in environmental conditions affect natural selection
as environmental conditions change, some adaptations may not be successful, and the selective pressure may change. This may lead into new adaptations, and eventually specition.
