An identical copy of an organism. All cells resulting from mitosis are clones. Identical twins are clones. Clones may be made by inserting a somatic nucleus into an enucleated egg but getting the organism to develop normally has remained a challenge to scientists.
Blood type -
A, B, AB & O are the 4 most common types for humans. Blood type is result of marker proteins on the surface of red blood cells. 'A' markers make A blood, 'B' markers make B blood, both 'A' and 'B' markers make AB blood and no markers make O blood. This is an example of 3 alleles for a trait (A,B, O) or multiple alleles and also co-dominance. Individuals get only 1 allele from each parent. Other blood types may be Rh positive or negative & MN blood groupings)
Preserved evidence that organisms lived long ago.
The theory that might explain the movement of continents. Pangea might have been the first land mass with all the continents together. The movement of these continents apart from one another may have created the different oceans and land masses we not associate with Earth.
Homologous structure -
Structures of two different organisms that are of the same origin and structure. These might indicate a common ancestor. Examples are the human arm, the bat wing and the dolphin flipper.
Individuals that look the same, interbreed with each other in nature and produce fertile offspring naturally.
The study of a developing organism before birth. Scientists think that since genes control development, if 2 different organisms go through many of the same phases during development, they must have many of the same genes and possibly a common ancestor. The more alike, the closer the common ancestor
Vestigial structure -
Body parts that are still present because the genes to make them are still there, but the parts are no longer functional. These may indicate a common ancestor.
Natural Selection -
All organisms are born with variations, some of which help them survive. Those organisms that have the survival traits live longer and reproduce more offspring - thus handing down their survival traits to more young. If the survival trait continues to be advantageous, most organisms in the species will have the same trait and it will become an adaptation. This is the process of evolution
The man who developed the process of natural selection to explain how certain organisms could be so similar yet different species. The process took him over 20 years to develop. He first noticed differences in organisms on his voyage as a ship naturalist. Then he returned home and did controlled breeding experiments on pigeons. He believed he had evidence to prove that only inherited traits could be passed to offspring and if these were advantageous, they would increase in frequency within the population
- A person who believed acquired traits could be passed from one generation to another.
The process that says change occurs over a period of time. Organisms today are not the same as they were in the past. New species may have developed and some may have gone extinct.
Gene pool -
All the genes in the entire population for all the traits of the organism.
Gene flow (Migration)-
The process of organism moving from one location to another. Immigration is moving into an area, Emigration is moving out. Both change the frequencies of genes in the gene pool - moving out of the area removes alleles while moving into a new area adds alleles to the gene pool.
Genetic drift -
A chance change in the frequency of a gene in the gene pool. This is usually more evident in very small populations but occurs quite often in all populations. Results because entire population is currently descendants from founding population and share many genes in common. (Amish have higher frequency of dwarfism than general population)
Organisms completely separated from each other, preventing the possibility of reproducing with each other. Occurs because of land forms (geographical) separating two group[s of the same species, or differences in mating rituals or seasons, possibly a change in chromosome numbers. May, eventually, result in a new species.
The Biblical explanation of how life on Earth came to be.
A change in a body structure that gives the organism a survival advantage. Examples include mimicry, camouflage, resistances to pesticides or herbicides, bifocal vision, walking upright, etc.
Endosymbiont hypothesis - symbiont = symbiosis)
Since chloroplasts and mitochondria contain their own DNA and self replicate, scientists think that they were once prokaryote organisms that became symbiotic with other unicelled organisms. The relationship stuck and they are now cellular organelles. (endo = within, symbiont = symbiosis)