Natural selection Flashcards
What’s adaption?
Any behavior or body characteristic that a living thing has developed to help it survive better in its environment.
Species
An individual type of living thing that shares enough DNA that it can reproduce with others of its kind
Theory
A well-supported and tested explanation for an observation of the natural world.
DNA
The molecule that has the instructional code for life
Organism
Another name for a living thing
Trait
A characteristic of a living thing
All _______ have characteristics that change over time.
species
________ is the change of characteristics in organisms over time, sometimes leading into new species.
Adaption
There were several scientists that realized that organisms change over time, but it was _______ ______ who was first to discover that living things change mostly due to the environment.
Charles Darwin
Darwin discovered that the environment _______ some characteristics or traits over others.
favored
Organisms born with advantages for getting food, avoiding predators, and surviving the climate and terrain were more ___ and had a higher chance of passing on their traits or genes to future generations.
fit
Organisms born with advantages for getting food, avoiding predators, and surviving the climate and terrain were more fit and had a higher chance of passing on their traits or _____ to future generations.
genes
This idea that organisms with traits best suited for their environment are more likely to survive is called the Theory of Natural Selection.
Theory of Natural Selection
In most species there are a lot of __________. These are differences in traits within a species, such as differences in size, shape, or color.
variations
New variations can arise through ________, which are errors or changes that occur in the DNA of a species.
mutations
Some mutations are _______. This makes it less likely for the organism to pass on its genes to future generations. These variations will get “selected” against.
harmful
But some mutations can be _________, making the organism more fit or more likely to pass on its genes to future generations.
beneficial
But some mutations can be beneficial, making the organism more ___ or more likely to pass on its genes to future generations.
fit
Given enough time of nature selecting the beneficial traits, a population’s traits can change so much that they can no longer breed with the original species. _________ has occurred.
Evolution
Remember - In _______ _________, whether a mutation is harmful or beneficial depends on the organism’s environment.
Natural Selection
