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NOVA - Evolution Ep 5 - Why Sex

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"Show 5: Why Sex?
57 minutes, 7 DVD chapters

Chapter 1. Prologue (2:40)
Introduction to the show's theme: sex and genes, driving behavior and driving evolution
All living beings are programmed to transmit their genes to the next generation
From an evolutionary perspective, sex is more important than life

Chapter 2. Lesbian Lizards (5:04)
Asexual reproduction and questioning the importance of males
A female-only lizard species gives birth without having had sex; each egg has a complete set of her mother's genes
If a female-only species can thrive, are males necessary?
The biological imperative to pass on genes

Chapter 3. The Advantage of Sex (9:46)
Exploring the evolutionary advantages to sexual reproduction
Studying asexual and sexual reproduction in Sonoran minnows to demonstrate the value of males
The Red Queen theory: when a species stops evolving, it is doomed
The evolutionary advantages of genetic variability among offspring
Speculating on the origins of sex
Descriptions of sperm and eggs: quantity versus quality
At a deep biological level, males and females want different things

Chapter 4. The Peacock's Tail (8:28)
Male ornamentation and the theory of sexual selection
Darwin's theory of natural selection explained traits that improved species' survival, but not extravagances like the peacock's tail
Why are ornaments typically seen on males?
Ornaments as an indication of good genes
Male competition and female choice, as seen in peacock mate selection
In some species, females choose good behavioral traits or good genes

Chapter 5. Songbirds and Monogamy (5:36)
Shared parenting and its evolutionary implications
Monogamy as a social solution to a biological dilemma
Female songbirds cheating on mates to give offspring better genes
Jacana birds and the reversal of male-female roles
Gender roles determined by who competes for mates and who cares for young

Chapter 6. Chimpanzees and Bonobos (8:13)
Social differences between two closely related species
Chimpanzee society is patriarchal and violent
Bonobo society is peaceful, due to female solidarity
Exploring how a change in feeding ecology influenced chimpanzee and bonobo differences
Implications for early humans, and humans today

Chapter 7. Sex and Human Behavior (16:44)
Exploring how modern human behavior springs from our evolutionary past
Evolutionary psychologists' provocative theories about humans and our drive to reproduce
Research into human scent and genetic compatibility
Mate selection and the evolutionary roots of attractiveness
Did brains evolve, in part, to attract mates?
Humans have gone beyond the biological urge, and will raise children that do not share our genes"

Duration 56m37s
Resolution 640x352
Video format DivX
Audio format AC3
Language english
Subtitles 0