Selfish Genes “outlaw genes” meiotic drive (segregation distortion) “packaging problem”...

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Transcript of Selfish Genes “outlaw genes” meiotic drive (segregation distortion) “packaging problem”...

Selfish Genes

“outlaw genes”

meiotic drive (segregation distortion)

“packaging problem”

Parliament of genes

Viruses

Frequencies (percentages) of ABO blood types among various human populations_______________________________________________________________________________

Location O A B AB Sample Size (N)_______________________________________________________________________________

France 41.5 50.4 6.0 2.1 752

Germany 38.1 41.6 14.1 6.2 6341

Hungary 31.1 38.0 18.7 12.2 1500

Iran 37.9 33.3 22.2 6.6 1000

India (Hindus) 30.2 24.5 37.2 8.1 2357________________________________________________________________________________

Gypsies (France) 22.1 25.7 38.1 14.1 113

Gypsies (Hungary) 28.5 26.6 35.3 10.0 975________________________________________________________________________________

Levels of Approach in Biology

• How? versus Why? Questions and Explanations

• Proximate and Ultimate Factors

• Mechanistic versus Strategic Perspectives

• Short-term versus long-term considerations

• Why do birds fly south in the autumn?

• Shorter day length triggers pituitary secretions that enhance Wanderlust.

• Winter is predictable and reduces survival. Birds that tended to move south escaped its icy clutches and survived to reproduce and left more genes in the population gene pool.

Debates and Progress in Ecology

Density Dependence versus Density Independence

Competition and Resource Partitioning

Group Selection

Niche Concept

Predation School

“Logical Primacy” of Null Models

Rabid Experimentalists

Statisticians

Equilibrium versus non-equilibrium

Theoreticians versus empiricists

Organisms are classified hierarchically5 Kingdoms: plants, animals, fungi, protists, bacteria

• Phylum Arthropoda

• Class Insecta

• Order Diptera

• FamilyDrosophilidae

• Genus Drosophila

• Species melanogaster

• Latin binomials

• Chordata

• Mammalia

• Primates

• “Hominidae” (Pongidae)

• Homo

• sapiens (the “sap”)

Prokaryotes

Eukaryotes

Reticulate Evolution

Endosymbiosis

Phylogenetics Phylogenetic Systematics = cladistics

Importance of shared derived characteristics

Monophyletic groups (Polyphyletic, Paraphyletic)

Sister groups, outgroups

Rooting phylogenetic trees

Identify ancestral states — polarize character state changes

Synapomorphy = shared, derived characteristic