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How do individuals and groups with different genes arise? Exams returned W 2/17? No discussions 2/15 or 16 Fig 5.26 Information flow in cells Protein Fig 13.5 As organisms reproduce the DNA is passed on to the next generations. Only a small percent of DNA codes for proteins Fig 21.7 DNA Composition: In humans: •Each cell contains ~6 billion nucleotides of DNA. •This DNA is ~2 meters long and 2 nm wide. •~98% does not directly code for amino acids •In a single human cell only about 5-10% of genes are expressed at a time. Fig 6.2 Length of human DNA in each cell The length of DNA in each of your cells is longer than you are tall. Width of DNA Power of ten: http://www.youtube.com/watch?v=A2cmlhfdxuY DNA Composition: In humans: •Each cell contains ~6 billion base pairs of DNA. •This DNA is ~2 meters long and 2 nm wide. •~1.5% directly codes for amino acids •~25% is genes •In a single human cell only about 5-10% of genes are expressed at a time. fig 21.7 Genes are replicators (selfish gene) fig 19.4 Viruses infect living cells, take over, and produce more virus. Bodies are vessels for the transmission of genes fig 21.8 Transposons Genes are replicators (selfish gene) Transposons: mobile DNA fig 21.9 fig 21.8 Barbara McClintock, discoverer of transposons fig 21.8 Transposons transposase transposon Genes are replicators (selfish gene) Transposons: mobile DNA fig 21.9 Retrotransposons: mobile and self-replicating DNA fig 21.9 fig 21.7 Genes are replicators (selfish gene) Evolution: A species’ genetic component changes as the individuals reproduce. These changes are based on how the DNA changes and who reproduces. Reproductive success = evolutionary success Reproductive success = Evolutionary success Reproductive success = Evolutionary success www.jayhosler.com Reproductive success = evolutionary success Are genes the only replicators? Memes: transmissible ideas • Ideas can act similarly to genes – Contain information – Replicate with imperfect fidelity Mutations Memes: transmissible ideas • Ideas can act similarly to genes or viruses – Contain information – Replicate with imperfect fidelity Memes: transmissible ideas • Ideas can act similarly to genes or viruses – Contain information – Replicate with imperfect fidelity Evolve: most successful replicators become most abundant Contrasts between memes and genes Genes Memes • Slow replication • Rapid replication • High copy fidelity • Low copy fidelity • Universal in organisms • Limited to some organisms – Only humans can transmit complex memes? Humans can pass on genes and/or memes Evolution of memes and genes Selection of memes and genes can be at odds NvN chpt 8 Do other animals have culture? In rats http://salmon.psy.plym.ac.uk/year3/PSY339EvolutionaryPsychology/EvolutionaryPsychology.htm Do other animals have culture? http://www.pbs.org/saf/1504/video/watchonline.htm Do memes make humans unique? Evolution: A species’ genetic component changes as the individuals reproduce. These changes are based on how the DNA changes and who reproduces. How do individuals and groups with different genes arise? Exams returned W 2/17? No discussions 2/15 or 16