Here is a great NOVA PBS documentary for an introduction to the theory and power of evolution:
The following is a simple introduction to evolution. We use sexual and natural selection principles to describe three important characteristics of Human life:
(1) genetic inheritance is defined as passing our genes on to our children through mating.
(2) individual variation. Each individual is unique and varies from all other individuals in natural traits and inheritance.
(3) instincts are pre-wired behavior circuits. We are pre-wired for certain behaviors, for example, sleeping, eating, drinking, seeing, hearing, fighting and fleeing.
A common definition of evolution is descent with modification. Descent means the passing on of genes from our ancestors to us as a group.
Biological evolution suggests that all life shares a common ancestor: all life on planet Earth is derived from more ancient species, going all the way back to one species. Sexual and natural selection are but two mechanisms for change, but undoubtedly the most influential ones to date in this pre-Singularic era.
Human sexual and natural selection in their simplest forms:
(1) Inherited traits exist. Traits include those of innate behavioral patterns that arise from universal brain circuitry, modifiable by nurture.
(2) The traits vary within a population from individual to individual.
(3) Survival and mating choice influence differential reproduction
(1) Some traits or innate behaviors are passed on through sexual encounters from those who survived and coupled. Mating begets beloved offspring, and the lucky couple has a chance to reproduce their genes and most of their traits. Recombining their genes into offspring which have half from each parent, but that also show variation by chance and small numbers of mutations, creates individual diversity. This process of establishing E-Potential offers chances for adaptation should the population encounter changing environmental pressures. Parents produce sperm and eggs that include our brainprints comprised of circuits of what worked before for all previous generations, both efficient and remarkable, and bugged and embarrassing, and flawed. Inject variability through the act of mating and gene recombination, and a mutation here or there, confers new E-Potential- if needed, for changing environments that might include different food sources, different competing tribes, climate changes, and any other chance occurrence steeped in unpredictable complexity.
Those who don’t survive, don’t reproduce: Their biological traits die with them. Thus we have tremendous will and inherited skills and equipment to survive and secure frequent sexual intercourse.
An adaption represents a functional result or capacity, like opposable thumbs, fast swimming sperm, efficient and nutrient filled eggs, accurate perception, empathy, a broad spectrum of other emotional capacities to label what’s important and decide what to do about it, or castles in the sky full of transPrimate imagination, all that tend to aid survival and/or mating and hence sexual reproduction. Adaptations, sometimes arising from mutations in the genetic code, are a good thing if you are a species. They greatly increase the chances of survival and reproduction. Without the ability to adapt to environmental change and its new forms of competition, and sometimes very rapid change, you are at risk for extinction– a Neanderthal adjustment disorder of grave proportions.
Just as natural selection arises from competition for survival, sexual selection arises from competition for reproduction. Sexual selection is achieved first by surviving, and then by the complex neocortical psychology of mate choice in primates, bringing into play perceptive and emotional intelligence, and sensitivity, not found in other animals. Healthy sperm that swim far and fast, and eggs that provide sufficient nourishment for baby don’t hurt.
Geoffrey Miller in The Mating Mind argues that the complex game of sexual selection in humans was the most likely cause of our larger brains and their unique capacities. (Miller, Geoffrey: The Mating Mind) The complicated dynamic of courtship leading to children also “gave birth” to our creativity, wit, compassion and expressive language and our other mental skills that separate us from other primates.
In Humans, a diversity of beliefs, instinctual and cultural behaviors, and individual spins underlies a diversity of mating choices, continuously rippling the surface of the gene pool. Too much unity or homogeneity can be as risky as everybody stopping sex as far as a society or species goes. With variation– diversity– one major environmental change can wipe it out completely.
For an excellent introduction on biological evolution, see: http://evolution.berkeley.edu/
Good example of ornamental sexual selection.
He is a crack-up, indeed. He is showing off his fitness. Sharp colors and jumping. Likely arose from the core principles of Ornamental Runaway– positive feedback loop where the female choice encourages more of this by choosing him as a mate. He can’t be sick or weak, and do his dance like that. Maybe she mates with him later because she has a sense of humor . Kids repeat the process, become a unique species. Sexual selection through mate choice accounts for the great diversity of appearances between species.
EVIDENCE FOR EVOLUTION
This international research appears in Nature July 31, 2014, one of the most prominent, respected, and cited scientific journals.
Today: 200 million year old Triassic rodent teeth simulated by researchers by varying proteins in embryonic development. The scientists reproduced, in the lab, the transitions observed in the “fossil registry of mammal teeth.”
Take-away: MultiCore Evolutionary Principle: Suggests not only does evolution undoubtedly exists but also “…evolution as a game between possible variations in form and natural selection.”
6 VIDEO SERIES showing irrefutable evidence for evolution to debate creationists. View each part separately or all at once with the last link.