We dont Know why we are here or how we got here

Contention 1 Rebuttals-Evolution: Human Beings Still Changing, Says Study- A new study suggests that humans aren't exempt from evolutionary pressures. Despite using culture and technology as ways of adapting to new environments, humans, like all other living things on Earth, undergo genetic changes as a response to conditions around them -- or in this case, favorable traits in their genes. In other words, we're all still evolving. Most discussion about our evolutionary history focuses on macroevolution, or changes occurring over long periods of time, including why our teeth are smaller when compared with our ancestors' and how our species may have interacted with Neanderthals. Instead, the study's authors provide an example of microevolution, or changes tracked in a few generations. The team, led by Canadian researchers, studied the small island town of Ile aux Coudres, located in the Gulf of Saint Lawrence in Quebec. Researchers looked at church records from 1799 to 1940, which provided detailed accounts of marriages, births and deaths. Because the vast majority of families have remained on the island with few newcomers arriving, it was possible to build extensive family trees from the demographic data. The team studied the age at which women are capable of giving birth, a trait that's heritable between generations. They found that the average age at which women on the island had their first child fell from 26 years to 22 years of age over the time period. But what makes the finding unique -- an example of microevolution -- is the relationship between younger childbirth and family trees. The trend closely follows genetic ties, and it increased over time, suggesting the trait was passed down and favored by natural selection. But how can scientists rule out social and cultural factors that affect when a woman first gives birth? Since the small island has a rather egalitarian history, social standing has been less of an issue. In addition, if cultural factors and better nutrition caused the spike in younger mothers, it would be traceable through all women suddenly, not through family lineages over time. Natural selection, as suggested by a researcher not involved in the study, may have even acted on a group of genes, not just one gene, responsible for sexual maturity, according to a New York Times article. Culture still matters, though, and one Wired blog post points out that social conditions still allowed for natural selection to occur, meaning conditions were favorable for it to happen. Humans are still evolving - and it's happening faster than ever- Humans are evolving more quickly than at any time in history, researchers say. In the past 5,000 years, humans have evolved up to 100 times more quickly than any time since the split with the ancestors of modern chimpanzees 6m years ago, a team from the University of Wisconsin found. The study also suggests that human races in different parts of the world are becoming more genetically distinct, although this is likely to reverse in future as populations become more mixed. "The widespread assumption that human evolution has slowed down because it's easier to live and we've conquered nature is absolutely not true. We didn't conquer nature, we changed it in ways that created new selection pressures on us," said anthropologist Dr John Hawks, who led the study. The researchers analysed data from the international haplotype map of the human genome, and analysed genetic markers in 270 people from four groups: Han Chinese, Japanese, Africa's Yoruba and northern Europeans. They found that at least 7% of human genes have undergone recent evolution. The changes include lighter skin and blue eyes in northern Europe and partial resistance to diseases such as malaria among some African populations, according to the study in Proceedings of the National Academy of Sciences. Some of the changes were tracked back to just 5,000 years ago, and "today they are in 30 or 40% of people because they [are] such an advantage," said Hawks. Many Chinese and African adults cannot digest lactose in milk, but across Europe a lactose-tolerance gene is now widespread. One reason is thought to be that at northern latitudes sunlight is weaker, so people make less vitamin D in their skin. Vitamin D is crucial for absorbing calcium, so being able to digest milk throughout life made people in colder climes healthier. The surge in global population had also led to faster evolution since more mutations occur, the researchers said. They believe that in future, the tendency to start families later in life will drive evolution. "People are having problems with infertility, so any kind of genetic variation that increases the success of later fertility will be selected for," said Hawks. Changing Regions of Genome Suggest Evolution is Still Occurring in Humans- Providing the strongest evidence yet that human beings are still evolving, researchers have detected some 700 regions of the human genome where genes appear to have been reshaped by natural selection, a principal force of evolution, within the last 5,000 to 15,000 years. The genes that show this evolutionary change include some responsible for the senses of taste and smell, digestion, bone structure, skin color and brain function. Many of these instances of selection may reflect the pressures that came to bear as people abandoned hunting and gathering for settlements and agriculture, a transition well under way in Europe and East Asia some 5,000 years ago. Under natural selection, beneficial genes become more common in a population as their owners have more progeny. Three populations were studied, Africans, East Asians and Europeans. In each, a mostly different set of genes had been favored by natural selection. The selected genes, which affect skin color, hair texture and bone structure, may underlie the present-day differences in racial appearance. The study of selected genes may help physical anthropologists explain why people over the world have a such a variety of distinctive appearances, even though their genes are on the whole very similar, said Spencer Wells, director of the Genographic project of the National Geographic Society. The finding adds substantially to the evidence that human evolution did not grind to a halt in the distant past, as is tacitly assumed by many social scientists. Even evolutionary psychologists, who interpret human behavior in terms of what the brain evolved to do, hold that the work of natural selection in shaping the human mind was completed in the pre-agricultural past, more than 10,000 years ago. “There is ample evidence that selection has been a major driving point in our evolution during the last 10,000 years, and there is no reason to suppose that it has stopped,” said Jonathan Pritchard, a population geneticist at the University of Chicago who headed the study. He and his colleagues, Benjamin Voight, Sridhar Kudaravalli and Xiaoquan Wen, report their findings in Tuesday’s issue of PLoS-Biology, a peer-reviewed, open-access journal published by the Public Library of Science, a nonprofit organization. The researchers’ data is based on DNA changes in three populations gathered by the HapMap project, a venture that built on the decoding of the human genome in 2003. The data, though collected to help identify variant genes that contribute to disease, also provide evidence of evolutionary change. The fingerprints of natural selection in DNA are hard to recognize. Just a handful of recently selected genes have previously been identified, like those that confer resistance to malaria or the ability to digest lactose in adulthood, an adaptation common in northern Europeans whose ancestors thrived on cattle milk.Contention 2 Rebuttals- Evidence?