Speciation
- Created by: Karimoja
- Created on: 24-12-14 16:40
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- Speciation
- Fossils
- All living things come from simple life forms
- These appeared on earth over 3 billion years ago
- Changed slowly over time through evolutuon
- Evidence of these things are fossils
- Remains of organisms in rocks
- How they are formed
- Hard parts of animals decay slowly and are replaced by minerals forming a fossil
- Marks like footprints and holes from roots that have been filled with minerals
- From parts of organisms that aren't decayed due to wrong conditions e.g. ice fossils
- Conditions needed for decay are oxygen, warmth and mosture
- Reasons there aren't more
- Many early forms of life were soft bodied and decayed fast
- Many fossils have been destroyed by geological activity
- All living things come from simple life forms
- Why animals become Extinct
- Climate change
- Not adapted to live in new climate and so die
- Natural Disaster
- Can cause climate change and affect large areas
- New Competition
- Fight for food, water and space, poorest competitor dies
- New Predators
- New unknown threats, don't know how to defend themselves
- New Disease
- Not protected from new diseases
- Climate change
- How new species are formed
- A species is a group of similar organisms that can breed together to produce fertile iffspring
- 1. Isolation
- 2 populations of a species become seperated
- 2. Genetic Variation
- In each population there is a range of characteristics
- 3. Natural Selection
- Alleles of a characteristic become more common
- 4. Forms a new species
- The population becomes so different that successful interbreeding is no longer possible
- Fossils
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