unit 7&8 definitions Flashcards
adaptation
is a structure, behavior or physiological process that helps an organism survive and reproduce in a particular environment
behavioural adaptation
the things an organism does to survive
Ex: migration, bird calls, playing dead
physiological adaptation
permit organism to perform special function
Ex: making venom, hibernation,
structural adaptation
physical features of a organism that help them to adapt
Ex: beak of a bird, fur on a bear,
mimicry
harmless species resemble (mimic) a harmful species so predators will avoid them
because they think they are harmful
variations
structural, functional or physiological differences between individuals.
variations within species
Through sexual reproduction individuals inherit a different combination of genetic information form parents (different alleles)
mutations
permanent changes in the DNA of an organism.
selective advantage
a genetic mutation that improves an organism’s chance of survival in a changing environment and therefore also increases its chance of reproduction
natural selection
process that results when the characteristics of a population of organisms change over many generations due to biotic or abiotic factors
selective pressure
When certain environmental conditions select (favour) for certain characteristics in some individuals and against different characteristics in another individual
fitness
the contribution an individual makes to the gene pool of the next generation by producing offspring that can survive long enough to reproduce
artificial selection
selective pressure from humans on populations in order to improve or modify desirable traits.
monoculture
planting of the same variety of species over a large portion of land, reducing genetic diversity.
palentology
study of ancient life through fossils
catastrophism
Earth experienced many destructive catastrophic events (floods, droughts, volcanic eruptions, etc.) which caused the extinction of species that were then replaced by new species form a region nearby
uniformitarianism
geological changes are slow and continuous (not catastrophic) and that slow subtle changes can result in substantial change
inheritance of acquired traits
idea that characteristics acquired during an organism’s lifetime can be passed to offspring
theory of evolution by natural selection
Theory explaining how life has changed and continues to change during Earth’s history
evolution
the process of genetic change in a population over time
survival of the fittest
organisms compete for limited resources. Organisms with favorable traits that help them survive will have an increased chance of reproduction.
descent with modification
theory that natural selection does not demonstrate progress but results in the ability to survive local environmental conditions.
what are the 5 sources for evolution
fossils, biogeography, anatomy, embryology, DNA
fossil record
The remains of traces of past life that are found in sedimentary rock; it reveals the history of life on Earth and the kinds of organisms that were alive in the past
transitional fossil
A fossil that shows intermediary links between groups of organisms and shares characteristics common to two separate groups.
vestigial structure
A structure that is a reduced version of a structure that was functional in the organism’s ancestors
biogeography
The study of the past and present geographical distribution of species populations
homologous structures
same origin/structure, different function
analogous structures
different origin/structure, same function
embryology
The study of early, pre-birth stages of an organism’s development
