BIO120H1 Lecture Notes - Lecture 11: Reciprocal Altruism, Allele, Organelle
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BIO120H1 Full Course Notes
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Document Summary
Organisms have not been getting more complex necessarily, but diversity between species has increased. Greater complexity arises from greater cooperation amongst previously independent organisms. A small number of events led to major changes in how inheritance worked. Previously independently evolving units merged, leading to high-level complexity through division of labor. Two prokaryotes joined nucleus to form modern prokaryotic cell. Selection increases the fitness of individuals, not the species. Showy colours good for sexual selection, but bad for predation. Traits good for species but that reduce fitness for individual cannot spread. High relatedness : genes that lead to helping relatives can spread via natural selection. Reciprocal altruism : in cases where organisms repeatedly encounter each other, mutual cooperation can lead to higher fitness. Genes are the ultimate unit of selection. Since genes are the unit of inheritance, ultimately the unit of selection is the gene. Genes are composed of unrelated genes and alleles that have been inherited from different places.
