unit 5. central ideas of evolution: ◦ life has a history ◦ it has changed over time ◦ and...
DESCRIPTION
Science tries to explain the past in terms of events/processes we can observe, measure and replicate today.TRANSCRIPT
Unit 5
Central Ideas of Evolution:
◦ Life has a history
◦ It has changed over time
◦ And different species share common ancestors.
Science tries to explain the past in terms of events/processes we can observe, measure and replicate today.
The variety of living things is called
biological diversity.
He contributed most to the understanding of evolution Born in England Naturalist on the crew of H.M.S. Beagle (1831) During travels, made numerous observations and collected evidence to propose how life changes over time.
Collected plant and animal specimens at every stop. Well educated and curious Strong interest in natural history Noted more diversity than his native country Collected 68 different beetle species in one Brazilian forest.
Darwin also found and collected fossils
He questioned: Why had so many species disappeared? How were they related to living species?
Actual Remains- Real tissue or portion of once living thing
Casts- Imprint in rock- Color of imprint same as surroundingMineral Replacement- Organic changed to mineral rock
1000 km west of South America
Influenced Darwin the most
Although islands close, they had very different climates. Most fascinated by land tortoises and marine iguanas
Pinta IslandIntermediate shell
Pinta
Isabela IslandDome-shaped shell
Hood IslandSaddle-backed shellHoodFloreana
Santa Fe
Santa Cruz
James
Marchena
Fernandina
Isabela
Tower
Although Darwin observed plants andanimals varied noticeably among different islands, couldit be possible they had evolved from an original South American species?
Darwin also knew that individuals differ from all the other members of its species
Sometimes differences easy to observe Sometimes differences are subtle Variation necessary for evolution by natural
selection
Do Lima Beans Show Variation?Procedure: 1. Count out 10 lima beans and measure the
length of each in millimeters. Record your results in a data table.
2. Combine your data with the data of two other classmates. Place all the data on one graph. Plot the length on the x-axis and the number of beans of each length on the y-axis.
Analyze your data and Make predictions.