Natural Selection Flashcards
What is natural selection (survival of the fittest)?
The ability of an organism to survive and reproduce in the environment in which it was living
What is a niche?
The role of an organism in the community
What are anatomical adaptations?
Involve the form and structure of an organism e.g. thick layer of blubber in seals and whales
What is a physiological adaptation?
Involve the way the body of the organism works and include differences in biochemical pathways or enzymes e.g. diving mammals can stay under water for longer than than non-diving mammals without drowning
What is a behavioural adaptation?
Involves changes to programmed or instinctive behaviour making organisms better adapted for survival e.g. insects and reptiles orientate themselves to get the maximum sunlight on their bodies when the air temperature is relatively low
What is industrial melanism?
Adapting to change colours in order to blend into the ash as a result of the Industrial Revolution e.g. moths changing from white to black to blend into the ash covered trees
What is directional selection?
Natural selection showing a change from one phenotypic property to a new more advantageous one
What is the process of antibiotic resistance?
-Take antibiotics to kill bacteria
-Some bacteria evolve to be resistant to the antibiotics
-These bacteria are not killed by the antibiotics
-When you don’t complete your full course of antibiotics, the resistant bacteria replicate and therefore most bacteria become resistant
-The next time you take antibiotics to kill bacteria, the bacteria will not die as most of it is resistant
What are some ways to overcome the problem of antibiotic resistance?
-Reducing the use of antibiotics
-Better education so people understand we don’t always need antibiotics
-Reducing the use of antibiotics in farm animals
-DNA sequencing to identify bacteria and find new ways of targeting them
-Development of new antibiotics
What are some factors that contribute to the problem of antibiotic resistance?
-Antibiotics too widely prescribed and used
-People do not complete courses of antibiotics making it easy for resistance to develop
-Antibiotics are widely used in the food chain
-Lack of basic hygiene in hospitals and care homes
-No financial incentive for pharmaceutical companies to develop new antibiotics
What is speciation?
The formation of new species as a result of isolation
What is hybridisation?
Where 2 closely related species breed and form fertile hybrids. This can be a cause of speciation.
What is geographical isolation?
A physical barrier separating individuals from an original population.
What is ecological isolation?
Two populations inhabit the same region, but develop preferences for different parts of the habitat
What is seasonal isolation?
The timing or flowering in some parts of a population drifts away from the norm for the group. This can eventually lead to the two groups reproducing several months apart.
