Download presentation
Presentation is loading. Please wait.
Published byClementine Shelton Modified over 8 years ago
1
Charles Darwin’s Theory of Evolution Charles Darwin explored the world on the Beagle for 5 years collecting specimens for the Museum of Natural History in London. www.homeworkuk.fsnet.co.uk/ science/inventcdarwin.html www.rit.edu/.../GalapagosPages/ SlideShow/SlideShow1a.html
2
Charles Darwin Galapagos Islands: a wide range of finch species descended from a single species. Different species adapted to different feeding niches (seeds, fruits, insects). Life Nature Library 1971
3
Charles Darwin Published his theory of evolution based on natural selection in 1859. Natural selection The increased reproduction of individuals that have traits (features / characters) better suited to survive and reproduce in an environment.
4
Traits Characters or features that are genetically inherited. They may be obvious, e.g. eye colour and height. They may be less obvious, e.g. aggression, speed, memory.
5
Evolution is the change in genetic make-up (traits) of populations through time (e.g. modern humans becoming taller). Population : members of a species that occupy a specific region and which come together to mate.
6
Biological species concept A group of interbreeding organisms that can produce fertile offspring. e.g. Homo sapiens – modern humans We can mate with anybody from anywhere in the world, and our children can have children. This makes us all ONE species.
7
Darwin observed: That all over the world, geological sequences contained simpler, more primitive forms lower down.
8
Genes are not the only factor that determine an organism’s appearance. Environmental influences: A person with a dominant gene for height could end up short due to poor diet and living conditions. Mutation: random change in an individual’s genes.
9
E.g. of a useful mutation: A lamb born with short, bent legs that prevented it from jumping fences. Used in breeding to establish short-legged sheep.
10
Traits that may ensure the survival of the fittest animal in a specific environment could include for example: An eagle that has inherited 1. very good eye sight for hunting 2. an ability to fly well 3. a means of attracting a lot of mates for reproducing with, e.g. a song.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.