Adaptations are features of organisms that aid their survival by allowing them to be better suited to their environment
These adaptations may be classified in a number of different ways:
Biological adaptations have a genetic basis (i.e. encoded by genes) and may be passed to offspring when the parents reproduce
Hence adaptations result in differential reproduction within a species, allowing for natural selection to occur
These adaptations may be classified in a number of different ways:
- Structural: Physical differences in biological structure (e.g. neck length of a giraffe)
- Behavioural: Differences in patterns of activity (e.g. opossums feigning death when threatened)
- Physiological: Variations in detection and response by vital organs (e.g. homeothermy, colour perception)
- Biochemical: Differences in molecular composition of cells and enzyme functions (e.g. blood groups, lactose tolerance)
- Developmental: Variable changes that occur across the life span of an organism (e.g. patterns of ageing / senescence)
Biological adaptations have a genetic basis (i.e. encoded by genes) and may be passed to offspring when the parents reproduce
- Organisms with beneficial adaptations will be more likely to survive long enough to reproduce and pass on these genes
- Organisms without these beneficial adaptations will be less likely to survive long enough to reproduce and pass on their genes
Hence adaptations result in differential reproduction within a species, allowing for natural selection to occur
Key points to consider:
- Natural selection occurs through an interaction between the environment and the variability inherent among the individual organisms making up a population.
- The product of natural selection is the adaptation of populations of organisms to their environment.
- Where and how an organism lives is largely due to its specific adaptations that allow it to survive and reproduce in a particular area or habitat
- In other words their structure allows them to function in that environment
- Polar bears are well adapted to life in the Arctic. They have a large layer of blubber to keep them warm. They are strong swimmers, aided by their strong forearms and layer of blubber for buoyancy. They have hollow fur to aid in insulation as well. For plants, cacti have water storage tissue and spines (prevent water loss) because of the infrequent rainfall in the desert.
Understanding:
5.2.U6: Individuals that reproduce pass on characteristics to their offspring.
Objective:
5.2.U6: Individuals that reproduce pass on characteristics to their offspring.
Objective:
- Contrast acquired characteristics with inheritable characteristics.
- State that only inherited characteristics can be acted upon by natural selection.
Survival in the struggle for existence is not random, but depends in part on the hereditary constitution of the surviving individuals. Those individuals whose inherited characteristics best fit them to their environment are likely to leave more offspring than less-fit individuals (= natural selection).
this unequal ability of individuals to survive and reproduce will lead to a gradual change in a population, with the inheritance of favorable characteristics accumulating over the generations.
In other words: Natural selection is differential success in reproduction ( unequal ability of individuals to survive and reproduce).
These organisms that survive and reproduce, pass these beneficial traits onto their offspring. Over many generations the accumulation of these beneficial genetic traits may result in a change in the population known as evolution.
For another species to develop, these genetically different individuals eventually have to become reproductively isolated (separated from the general population) where they will only reproduce with individuals with similar genetic traits.
Acquired characteristics of an individual such as large muscles are not passed on to an organism’s offspring
this unequal ability of individuals to survive and reproduce will lead to a gradual change in a population, with the inheritance of favorable characteristics accumulating over the generations.
In other words: Natural selection is differential success in reproduction ( unequal ability of individuals to survive and reproduce).
These organisms that survive and reproduce, pass these beneficial traits onto their offspring. Over many generations the accumulation of these beneficial genetic traits may result in a change in the population known as evolution.
For another species to develop, these genetically different individuals eventually have to become reproductively isolated (separated from the general population) where they will only reproduce with individuals with similar genetic traits.
Acquired characteristics of an individual such as large muscles are not passed on to an organism’s offspring