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Molecular Evidence. Analyzing Amino Acid Sequences to Determine Evolutionary Relationships. Zach, Sally, and Sarah. Learning Target. 1. Students will know examples of scientific evidence that support the theory of evolution. Evolution. All organisms - common ancestor
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Molecular Evidence Analyzing Amino Acid Sequences to Determine Evolutionary Relationships Zach, Sally, and Sarah
Learning Target 1. Students will know examples of scientific evidence that support the theory of evolution.
Evolution • All organisms - common ancestor • branched off, forming the phylogenetic tree. • Scientists have used various methods to research and prove this theory such as: fossils, embryos, and molecular evidence.
Molecular Evidence • Looking at the molecules of different organisms have shown that: • very similar: plasma membrane, RNA, & DNA • universal genetic code to produce proteins • 500 genes common to all species • over time, some organisms have slowly differentiated their DNA, forming new species • more similar DNA = more similar species • example: humans & chimpanzees • most convincing evidence for evolution = studying amino acid sequences
Amino Acid Sequences • Similar species to the human had similar amino acid sequences. • Species that are not so similar to humans have more different amino acid sequences. • Amino acid sequences are responsible for a species features.
How/why - Change in DNA • Evolution = change in a gene pool over time • As organisms adapted to their environments, their genes mutated and/or recombined in different ways during reproduction and were passed on to future generations • Five Fingers of Evolution • Small Population • Non-random mating • mutations • gene flow • natural selection
Example #1 Humans - Horses • Portion of an amino acid chain • #104-#116 of 146 Human ARG-LEU-LEU-GLY-ASN-VAL-LEU-VAL-CYS-VAL-LEU-ALA-HIS Horse ARG-LEU-LEU-GLY-ASN-VAL-LEU-ALA-LEU-VAL-VAL-ALA-ARG
Example #2 Humans - Chimpanzees • Same exact portion of amino acid chain Human ARG-LEU-LEU-GLY-ASN-VAL-LEU-VAL-CYS-VAL-LEU-ALA-HIS Chimp ARG-LEU-LEU-GLY-ASN-VAL-LEU-VAL-CYS-VAL-LEU-ALA-HIS