BIOL1003 Lecture Notes - Lecture 23: Spermatophore, Female Sperm Storage, Tettigoniidae
Natural Selection
Example:
1. Eye spots on the back of frogs- startles predators
2. Male blue bird of paradise
• Hangs upside down- not required for sperm transfer
• Plumes hinder survival
• Females don’t have these characteristics
3. Red deer
Sexual characteristics
• Primary sexual characters
◦ Essential for reproduction
◦ e.g. marsupial pouches, mammary glands, ovaries, testes
• Secondary sexual characters
◦ Not essential for reproduction
◦ Bright plumes, displays antlers
Sexual selection: selection for traits that are solely concerned with increasing mating
success compared with other members of the same sex
Individuals that are more successful leave more offspring
Intra sexual selection
• Competition amount members of one sec for axes to jet other
• Usually male to male competition
◦ Red deers
▪ Males: have antlers renown each year
▪ Roar
▪ Females don’t have these characteristics
◦ Hercules beetles
▪ Horns as weapons
▪ Large body size
◦ Male damselfly
▪ Guarding laying female by grabbing her around the neck
▪ Uses sperm removal organs on penis to remove sperm storage in
females by fertilising
◦ Lion
▪ Males take over pride every 2-3 years, males kill cubs when they take
over a pride.. so females become fertile more quickly
▪ Conflict between sexes (
▪ Infanticide probably bad for the species
▪ Females try to thwart males
Intersexual selection
• Choices by one sex among members of there other sex
• Usually female choice
◦ Spermatophore in a female katydid
▪ spermatophore provided by male and teen by female to make more eggs
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Document Summary
Essential for reproduction e. g. marsupial pouches, mammary glands, ovaries, testes. Example: eye spots on the back of frogs- startles predators, male blue bird of paradise, hangs upside down- not required for sperm transfer, plumes hinder survival, females don"t have these characteristics, red deer. Sexual characteristics: primary sexual characters, secondary sexual characters. Sexual selection: selection for traits that are solely concerned with increasing mating success compared with other members of the same sex. Individuals that are more successful leave more offspring. Intra sexual selection: competition amount members of one sec for axes to jet other, usually male to male competition. Guarding laying female by grabbing her around the neck. Uses sperm removal organs on penis to remove sperm storage in. Males take over pride every 2-3 years, males kill cubs when they take over a pride so females become fertile more quickly. Intersexual selection: choices by one sex among members of there other sex, usually female choice.
