1 / 10

Darwin and Wallace (1858) Theory of adaptive radiation Studied finches on Galapagos Islands

Darwin and Wallace (1858) Theory of adaptive radiation Studied finches on Galapagos Islands Different size and shape of beak relates to different foods. Beaks adapted to eat different types of leaves, worms, seeds etc. Embryonic development of many species is similar

hada
Télécharger la présentation

Darwin and Wallace (1858) Theory of adaptive radiation Studied finches on Galapagos Islands

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Darwin and Wallace (1858) Theory of adaptive radiation Studied finches on Galapagos Islands Different size and shape of beak relates to different foods. Beaks adapted to eat different types of leaves, worms, seeds etc

  2. Embryonic development of many species is similar May mirror evolutionary changes

  3. Look at these two moths on a lichen-covered tree. Which do you think the birds will find most easily? Which is most likely to survive long enough to breed? Which will pass on more of it’s genes?

  4. Look at these two moths on normal bark. Which moth is most likely to survive long enough to breed in this habitat? The brown moth will survive better on trees with little lichen, whereas the lighter moth is better adapted to lichen covered trees.

  5. Directional Stabilising Disruptive Evolution No evolution Evolution

  6. Intrasexual selection • Usually between males • Fight for the right to mate Intersexual selection • Females select males • Occasionally the other way

  7. Genetic variation • Natural selection can only select for variations that already exist. Without genetic variation, there could be no selection • Greater variation in a population increases adaptive ability and, therefore, survival of the population

  8. Evolution Occurs because there is genetic variation Genetic Drift: RANDOM changes in allele frequencies over time. Particularly fast in small populations Natural selection– NOT RANDOM, better adapted individuals survive better &/or reproduce better & pass on more of their genes

  9. Videos • Wolfe: Natural Selection I & II • http://videos.howstuffworks.com/science-channel/29786-100-greatest-discoveries-natural-selection-video.htm

More Related