Darwin & Evolution

Natural Selection

Natural selection is a process by which organisms that are most suited to their environment survive and reproduce most successfully; also called survival of the fittest.

Natural Selection occurs in any situation in which more individuals are born than can survive, there is natural heritable variation, and there is variable fitness among individuals.

It occurs through adaptation because it is heritable characteristic that increases an organism's ability to survive and reproduce in an environment

It occurs through fitness because it is how well an organism can survive and reproduce in its environment

Evidence of Evolution

Patterns in the distribution of living and fossil species tell us how modern organisms evolved from their ancestors

Many recently discovered fossils form series that trace evolution of modern species from extinct ancestors

Homologous structures that are similar in different species of common ancestry

Similar patterns of embryological development provide further evidence that organisms have descended from a common ancestor

At the molecular level, the universal genetic code and homologous molecules provide evidence of common descent


Created with images by BioDivLibrary - "n54_w1150" • brian.gratwicke - "Toad Mountain Harlequin frog (Atelopus certus) Female left, male right. This species is now secure in captivity and has recently been captive-bred for the first time by Dr. Ibanez and his team." • ARTchemist* (AWAY) - "pretty in blue" • Frank.Vassen - "Madagascar Pygmy Kingfisher (Corythornis madagascariensis), Mantadia National Park, Madagascar" • USFWS Mountain Prairie - "Mountain Bluebird" • Frank.Vassen - "Red-tailed Sportive Lemur, Kirindy Forest, Madagascar" • 2554813 - "duck wild mallard" • dimitrisvetsikas1969 - "cyprus lizard kurkutas" • Jazzyroses - "Animal Kingdom 602" • PublicDomainPictures - "animal bone bones" • PublicDomainPictures - "dinosaur lizard fossil" • C@mera M@n - "IMG_0592" • Efraimstochter - "fossil skull head" • phylofigures - "pgen.1000627.g002" • phylofigures - "pgen.0010044.g003" • shankar s. - "Balut/ balot (eeew!)" • cgalvin233 Colleen - "Week one axolotl embryo" • allispossible.org.uk - "Molecule display" • Kovescence - "science science class molecule"

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