BIOL 120 MACROEVOLUTION
New species (speciation)
Over a very long time
What is a species?
A group of individuals that, in nature, can interbreed & produce fertile offspring but
cannot reproduce with members of other species.
A single species makes up an impermeable container for its gene pool.
• Temporal Isolation
Different breeding seasons
• Behavioral Isolation
No mate attraction due to behavioral differences
• Ecological Isolation
• Mechanical Isolation
Physical incompatibility of reproductive structures
• Gamete Isolation
Gametes don’t fuse – sperm does not penetrate egg
• Hybrid Inviability
Hybrid doesn’t survive long after conception
• Hybrid Infertility