Terms : Hide Images
| 216497125 | biological evolution | genetic changes in the populations of living organisms | |
| 216497126 | Charles Darwin | Proposed natural selection as mechanism for biological evolution "On the Origin of Species by Means of Natural Selection" - 1859 | |
| 216497127 | natural selection | process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species | |
| 216497128 | chemical evolution | chemical changes that occured to earth during its first billion years of existence that allowed it to become hospitable for living organisms | |
| 216497129 | fossils | used to determine which organisms lived in the past; mineralized or petrified replicas of skeletons, bones, teeth, shells, leaves, seeds, etc. | |
| 216497130 | ice cores | used to determine which organisms lived in the past; drilled from glacial ice to analyze chemicals found within | |
| 216497131 | DNA analysis | used to determine which organisms lived in the past; genetic samples from fossilized remains are compared to genetic samples from organisms alive at the present | |
| 216497132 | mutation | change or mistake in the DNA of an organism; occur naturally and sometimes caused by exposure to toxins and/or radiation; lead to genetic variability in a population; can be good, bad or neutral | |
| 216497133 | differential reproduction | some organisms get to reproduce at higher rates than others; organisms with traits that help them survive and allow them to well suited for their environment will reproduce at higher rates than organisms that are ill adapted to their environment | |
| 216497134 | adaptation / adaptive trait | genetic characteristic that allows an organism to survive better | |
| 216497135 | coevolution | 2 organisms/populations changing genetically in response to each other; ex: bats and moths | |
| 216497136 | hybrid / hybridization | 2 distinct species breeding and creating a new unique species; rarely occurs in nature; more common due to human research and human influences; ex: beefalo, liger, etc. | |
| 216497137 | horizontal gene transfer | transfer of genes from one organism/genome to another through mechanisms such as transposable elements, plasmid exchange, viral activity, and perhaps fusions of different organisms | |
| 216497138 | tectonic plates | sections of the Earth's crust that move due to convection currents | |
| 216497139 | ecological niche / niche | organisms way of life; what resources it uses, how and when it uses those resources, etc. | |
| 216497140 | generalist species | broad habitat and niche; can live in many places and many conditions; ex: grey squirrel, white-tail deer, cockroach, raccoon, etc. | |
| 216497141 | specialist species | narrow habitat and niche; can only live in very specific places and under very specific conditions; ex: giant panda, orchids, etc. | |
| 216497142 | evolutionary divergence | process whereby natural selection causes populations to become more different over time | |
| 216497143 | speciation | formation of new species | |
| 216497144 | geographic isolation | form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water | |
| 216497145 | reproductive isolation | separation of species or populations so that they cannot interbreed and produce fertile offspring | |
| 216497146 | extinction | total loss of a species | |
| 216497147 | endemic species | organism that is found only in one very specific location | |
| 216497148 | background extinction | natural extinction rate; some species will go extinct under normal conditions as environmental conditions change; ex: one to five species for each million species on earth | |
| 216497149 | mass extinction | large number of species going extinct in a very short period of time; ex: there have been 5 mass extinctions over the last 500 million years; ex: dinosaurs going extinct is an example of a mass extinction | |
| 216497150 | mass depletion | widespread, often global period during which extinction rates are higher than normal but not high enough to classify as a mass extinction | |
| 216497151 | artificial selection | selection by humans for breeding of useful traits from the natural variation among different organisms; ex: different breeds of dogs | |
| 216497152 | genetic engineering | the transfer of a gene from the DNA of one organism into another organism, in order to produce an organism with desired traits | |
| 216497153 | gene splicing | the process by which the DNA of an organism is cut and a gene from another is inserted | |
| 216497154 | recombinant DNA | genetically engineered DNA made by recombining fragments of DNA from different organisms | |
| 216497155 | genetically modified organisms (GMO's) | organisms whose genetic code has been altered by artificial means such as interspecies gene transfer; Currently 82% soybeans, 71% cotton and 1/4 corn grown in US are GMO's | |
| 216497156 | cloning | making a genetically identical copy of DNA or of an organism |
