Maximum Thrift is a method / philosophy that considers the shortest tree (in number of transformation steps) the best hypothesis about the phylogenetic relationship of a given set of terminals. Transformation step is the cost attributed to the change of character state in a given branch of the tree, be it the change from one nucleotide base to another, amino acids, or the color of an animal's iris. The fewer transformations, the shorter the tree, and therefore the more parsimonious. In this method, what programs do is to investigate as many alternative topologies as possible (or all if their array has less than 25 terminals; see more details below) given their character array. Each will be measured, and the shorter (optimal) trees will be retained as the most parsimonious result.
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Grizzly bears: As predators, bears keep down the numbers of several species, like moose and elk. They also carry and deposit seeds throughout the ecosystem. Bears that eat salmon will leave their dropping and the partially eaten remains that provide nutrients such as sulfur, nitrogen and carbon to the soil.
Answer:
Renewable Energy Resources.
Explanation:
Unlike fossil fuels which cannot be recovered when destroyed, these sources of energy can be recovered by a means of recycling . Recycling here reduces solid wastes which is one of the causes of land pollution.
Hydroelectric schemes can only be built in mountain regions where rainfall and rivers are plentiful which involves upset of aquatic ecosystem. This poses a dangerous pollution problem though.
Wind generators and solar panels are not very efficient energy producers. However, future schemes for producing solar energy via solar satellites are promising.
Answer:
The antibodies produced by a vaccine only fight specific antigens.
Explanation:
Antibodies only bind to specific antigen during an immune reaction. The introduction of foreign substance in the body stimulate the B-cells to produce antibodies that fight against infections. Only specific antibodies are produced following antigen presenting cells that bind to antigens. They capture and display the antigens to the antibodies.
There are three main types of galaxies<span>: Elliptical, Spiral, and Irregular. Two of these three </span>types<span> are further divided and classified into a system that is now known the tuning fork diagram. When Hubble first created this diagram, he believed that this was an evolutionary sequence as well as a classification.</span>
