Molecular evidence

?
View mindmap
  • 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
    • 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
    • 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
    • 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

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all DNA, genetics and evolution resources »