PP1-3 Test Flashcards
(134 cards)
a proposed explanation for phenomena to guide investigations
hypothesis
repeatedly tested hypotheses used to explain and predict phenomena or accepted explanation for observations, backed by scientific evidences
theory
Worked in 1830’s to 1850’s
In 1859, wrote his ideas about evolution (which at that point was a hypothesis) in a book called
On the Origin of Species by Means of Natural Selection
(basically a journal of his observations & questions), he didn’t call his ideas “evolution
charles darwin
3 word phrase for what Darwin called his hypothesis as proposed in his book…
this means that genes are modified (or changed/varied) & some of these changes are passed to an organism’s descendants & if it allows them to be better suited for their environments it leads to adaptations
“descent with modification”
Darwin’s ideas of evolution are now a ____ because of the repeated evidences that support it
theory
States that…“Organisms change gradually over time as a result of adaptations”
As the organisms change, their variation allows for differential survival and reproduction because nature selects, or allows, for the individual organisms that are best suited to their environment to pass on their traits to their offspring leading to adaptations and evolution of the species
Gradualism AKA Darwinism
change between species over time, one species replaces another, old species go extinct when replaced (will learn this later such as dinosaurs replaced by mammals)
macroevolution
change within species over time, see next slide, microevolution leads to macroevolution
Change within a species’
microevolution
microevolution ex.
Genetic variations occur for a variety of reasons If genetic variations are heritable and beneficial, then individuals pass on their traits to their offspring, if some survive “better” than other others then.. Natural selection (over many generations) allows members of the species that survived to produce more offspring and keep passing on these “variations” to their offspring Natural selection leads to an organism’s adaptations to their environment Evolution results
4 Principles of Darwin’s Theory of Evolution (by means of natural selection)
overpopulation, genetic variation, Struggle for existence/ Survival of the fittest, Natural selection
random variances or differences between individuals, the ‘why’ or ‘raw material’ for evolutionary change
genetic variation (heritable)
when individuals with heritable variations are better adapted they are chosen by nature to survive and reproduce, the ‘how’ or ‘mechanism’ for evolutionary change
natural selection
More babies born than can survive since so many things in environment can affect their mortality
overpopulation
Random differences or variations occur between individuals within the same species due to ________(exs. mutation or sexual reproduction and meiosis) but only heritable traits are passed onto offspring
genetics
Competition occurs between individuals such as predator with prey, male with male, or plant with plant. Competition occurs for living space, food, water, mates, etc. The organisms with the best heritable variations will survive due to being the most “fit” or best adapted to reproduce
Struggle for existence/ survival of the fittest
Natural selection allows those organisms with the most suitable heritable traits to survive and reproduce and pass those traits onto their offspring leading to adaptations BUT it does NOT produce perfection and does NOT have a goal and is NOT random, although variation is
Natural selection through differential survival and reproduction
Mutation, sexual reproduction, and genetic recombination during sexual reproduction lead to _______ ______
genetic variation
CAN lead to inheritance, if so then their can be a struggle for existence/survival of the fittest
genetic variation
Then _______ ________ occurs due to differential survival and reproduction which then leads to adaptations
natural selection
BUT if humans intervene then _______ _______ can have the same outcome
artificial selection
are “characteristics that result from natural selection when (heritable) traits are passed onto offspring resulting in organisms being better suited to their environment”
Often occur because of changes in organisms’ habitat
adaptations
Structural
way a structure looks
Anatomical (or morphological) adaptations
Functional
Helps a structure do something better
Physiological adaptations
If there is an anatomical adaptation, it is for a _______l reason
_______adaptations occur and result in anatomical changes as well
Physiological