changes to the bones or limbs or organs of an organism to help to survive
ex. talons and eyesight of an owl or the leaves of a buffaloberry
behavioural
the actions an organism takes to survive
ex. wolves hunting in packs
"broken" wing of the kill deer
physiological
sometimes called function, it is the generalfunction of different parts of the body
ex. gopher's slowing down their breathing rate during hibernation
-production of hormones in humans
variation is created by sexual reproduction and the mixing of genes from both parents
variation is also increased by mutations
-mutations are changes in the geneticmaterial of an organism that may cause new characteristics to appear, may cause cells to die, or malfunction or may even cause tumours
aristotle
believes all life existed in a perfected and unchanging form
buffon
first to believe that there were relationships between organisms, earth was older than 6000 years
cuvier
developed paleontology (study of life through fossils), discovered many changes in species, some appearing, some drying off, sudden events he called revolutions
lyell
disagreed with revolutions, felt changes were slowgradual, and these changes are still occuring today
lamark
came up with the idea theory of " inheritance of acquired characteristics"
-this meant that the traits an individual developed would be passed on the offspring
-there was a "force" or desire in organisms that allowed them to change themselves and then through use or disuse these features became more or less commons
darwin
traveled on the beagle, made many observations of the new world and came up with a new theory of change still used today
wallace
came up with a similar theory as darwin and conversed with darwin
malthus
mathematician who came up with the idea that populationsproduceoffspring that can actually survive
overproduction
number of offspring produced is greater than the number that will survive to adulthood and survive
struggle for existence
organisms of the same species must compete for resources due to overproduction
variation
because of overproduction, there are differences between members of the same species
survival of the fittest
those individuals in a species with traits that give them an advantage are better able to compete, survive, and reproduce. all others will die
inheritance of successful variations
over many, many generations, a new species will arise due to the many advantageous characteristics becoming more common.
-these traits must be passed on to the offpring
fossil record
provides order of life because the deeper, the older the fossil. Younger layers are more similar to today's organisms
-has now been proven through radiometric dating using isotopes
transitional fossil
fossil that show intermediary links between groups of organisms that link past and present
ex. organisms in drumheller and china
patterns of distribution
darwin and wallace used the study of biogeography (study of past and present geographical distribution) to predict that animals evolve in one area and then spread out to other regions
ex. geographically close areas have related species
anatomy
relationships in structures of organisms
homologous structures
similar structural elements and origin but may have different functions
ex. horse leg, bat wing, and human arm
analogous structures
body parts that perform similarfunctions but do not have evolutionary origin
ex. insect and bird wing
vestigial structures
structures that seem to be disappearing
ex. wisdom teeth and appendix
embryology
similarities among youngembryos in related groups point to a common ancestral origin
molecular biology
-study of parts of cells show us similarities
all cells have a membrane
proteins called enzymes do work
proteins all come from amino acids
all cells have dna
dna is more similar organisms
genetics
we now know how parents pass traits on to their offspring
-understand the functions of dna
artificial selection
the way we have created new vegetables and bred for newtraits in dogs suggest evolution is possible
speciation
formation of a new species can occur through 2 methods
transformation
gradualdevelopment of a new species as a result of mutation and adaptation to a changing environment
ex. one butterfly changes into a new one
divergence
new species come from an original but the original remains in existence. results in many new individuals
ex. the galapagos finches
geographical barriers
mountains, rivers; does not need to be permanent but must be present long enough to cause organisms to become reproductive incompatible
biological barriers
behaviours that change cause reproduction to be impossible. examples include bird calls and the leopard frog calls that are no longer recognized
reproductive barriers
organisms are ready to mate at different times of year or sperms and egg will not join
ex. finches
physical barrier separates on group from another mutations occur
natural selection works on the two groups differently creating unique variation in each group
accumulated differences between the populations become so numerous that even if the groups are reunited, the cannot interbreed