Charles Darwin and Natural Selection Flashcards
What did Charles Darwin do in terms of natural selection?
Proposed a mechanism of evolution he called natural selection
What did Charles Darwin say about natural selection?
Stated that this process of evolution has been taking place for millions of years
Natural Selection
Process by which individuals better suited to their environments survive and reproduce the most successfully
(also referred to as survival of the fittest)
Darwin believed that natural selection worked on populations because of the presence of _______ _______
natural variations
Natural Variation
differences among individuals of the same species
Natural variation can be found in ___ species according to Darwin.
all
Natural variations ___ be passed down to the next generation, according to Darwin.
can
Where does natural variation come from?
sexual reproduction, genetic mutations, and crossing over
4 major parts of natural selection that drive evolution
genetic variation, selective pressure, survival (of the fittest), reproduction
fitness
the ability to survive and reproduce in a particular environment
adaptation
any inherited characteristic that increases an organism’s chance of survival
What happens to individuals with low fitness?
die or produce a small number of offspring
Adaptations can be…
physical, biochemical, behavioral
(porcupine quills, resistance to pesticide, hunting in a pack)
selective pressure
a pressure put on by environment that favors a certain phenotype
common ancestry
a species that is the ancestor of two or more different species later in time