Charles Darwin’s theory developed in AD 1859, in his book Origin of Species. Darwin theorized that humans evolved from a lower order of animals, such as primates. A change in the genetic composition of a population of organisms over time.
deoxyribonucleic acid The genetic material that severs as a “recipe” for material/cells/organisms. It’s a complex molecule that is structured like a twisted ladder
sections of DNA which serve as “recipes” for the production of specific products
different version of the same gene they create diversity
any changes in the DNA of an individual. * most commonly arise form mistakes made during the reproduction of DNA
chemical and or radiation that may cause a mutation EX. UV radiation, X-rays, Gamma rays, Bromine(gas and peptides), Benzene( solvent and gas) Mercury (comes form coal)
Mutations can be
Beneficial, benefit an organism in some way. Neutral, do not help or harm an organism Harmful, harm an organism in some way often lethal or may make an individual sterile.* The vast majority are harmful!
if a mutation occurs in a sex cell, it may be passed to offspring and spread into a population. Mutations in other cells may affect an individual but cannot be passed to offspring.
population typically have a great deal of genetic diversity even if it is not visible to us. It’s from the spread of different mutations within a population, but not through the entire population
how fast mutations spread depends heavily on the reproductive rate of the organism. Example: bacteria vs. zebras. Remember harmful mutation often kill an organism or lessen the likely hood to reproduce
The Theory of Natural Selection
a scientific theory developed by Charles Darwin and covered in “On the Origin of Species in 1859”
Survival of the Fittest
being the fittest doesn’t necessarily mean being the strongest, fastest, etc
It is the driving force of evolution and natural selection. (Selective pressure is any phenomena which alters the behavior and fitness of living organisms within a given environment.)
describes cases where two (or more) species reciprocally affect each others evolution cases where two (or more) species reciprocally affect each others evolution Example to dry-dig a well, to cold- get heat, disease- treatment
is typically slow and gradual process, so rapid changes in selection pressure can have dramatic effect on population. if a change in selective pressure occurs slowly population usually have time to adapt. Ex: the evolution of co-existing predators and prey
soon to become extinct over all or most of its natural range
likely to become endangered in the near future
when a species is no longer found anywhere on the earth
Local extinction(Florid panther)
when a species is no longer found in a area that it once inhabited, but can still be found in other areas
few members of a species left that it no longer plays it’s role in an ecosystem
any significant rise in the number of species extinction above the background extinction rate
Number of mass extinctions
5 mass extinctions each of which wiped out between 50% and 95% of the species on earth. We are literally living in the beginning od the 6th mass extinctions
is the sequence of who eats whom in a biological community (an ecosystem) to obtain nutrition.
is organic material made from plants and animals (microorganisms. Biomass contains stored energy from the sun.
all the processes by which nutrients are transferred from one organism to another. (nutrient cycling) Six ecological services that species provide humans: ________, pollination, pest control, recreation, soil formation and maintenance, climatic regulation.
found in the atmosphere, but in this form it is unusable by plants and animals * Many bacteria can use and convert it to forms that plants use, when organism die and decompose these are converted back into nitrogen gas
cyclic movement of phosphorus in different chemical form from the environment to organism and then back to the environment
water evaporates from the sea etc.
carbon exist in the atmosphere primarily as carbon dioxide which is produced by animals & fires and release by volcanoes(taken up plants phytoplankton coral)limestone (CaCo2), fossils fuels
large regions such as forests, deserts, and grasslands characterizes by a different climate and specific forms of life,especially vegetation, adapted to it
the movement of species into areas that are not their natural range Ex: LION FISH
Rapid environment change
several hundred years natural(forest fires) vs. unnatural(global warming)As human population grows the more strain is put on the ecosystem
Genetically based changes in the appearance, function and or behavior of organisms through successive generations.
Five ways for extinction to occur:
over hunting/collecting, habitat destruction, pollution, introduction of alien/invasive spp, rapid environmental change
Six ecological services
Six ecological services that species provide humans: nutrient cycling, pollination, pest control, soil formation and maintenance, climatic regulation,recreation
organism that feeds on plants or on other producers(detritivore, omnivore, secondary consumer)