<span>The 1-kg ball accelerates twice as much as the 2-kg ball.</span>
<span>More individuals are produced each generation that can survive.
Phenotypic variation exists among individuals and the variation is heritable.
Those individuals with heritable traits better suited to the environment will survive.
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When reproductive isolation occurs new species will form.</span></span>
Science is based on the feature of "<span>detailed research with reliable sources" among many other things. It is crucial that the tests can be repeated with the same results. </span>
Its called the greenhouse effect