Molecular evidence
- Created by: Yzyl Quintana
- Created on: 09-02-17 15:51
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- Techniques providing evidence for Evolution
- 1) DNA hybridisation
- DNA relatedness measured by the temperature needed to denature the hybrid DNA
- More similar the base sequences of the 2 species, the better they will stick together. Therefore higher temperature needed
- Measuring the similarity between the genomes of the 2 species
- DNA relatedness measured by the temperature needed to denature the hybrid DNA
- 2) DNA profiling
- If mutations have occurred in some of there DNA sequences, the enzymes will not cut the DNA
- Size of the fragments and hence position of the bonds produced will change
- Allows scientists to see how closely related species are in evolutionary terms
- More bonds match = more closely related
- If mutations have occurred in some of there DNA sequences, the enzymes will not cut the DNA
- 3) DNA & Protein sequencing
- Comparing protein/base sequences of different species
- Few differences = evolved from a common ancestor more recently than organisms with more differences
- Comparing protein/base sequences of different species
- 4) DNA molecular clocks
- DNA base sequences determined from PCR & automated DNA - sequencing machine
- For a given gene, the mutation rate is fairly constant
- The molecular change in DNA overtime can be used as a 'molecular clock', which can be used to pinpoint events in evolution
- Compare no. of differences between species = can calculate how long ago they shared a common ancestor
- 1) DNA hybridisation
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