Junk DNA and junk science
Rudimentary organs ... are useless, or nearly useless, and consequently are no longer subjected to natural selection.
Appendix, human tailbone, etc...
The lowly appendix, long-regarded as a useless evolutionary artifact, won newfound respect two years ago when researchers at Duke University Medical Center proposed that it actually serves a critical function. The appendix, they said, is a safe haven where good bacteria could hang out until they were needed to repopulate the gut after a nasty case of diarrhea, for example.
[The Coccyx] is an attachment point of a number of muscles at the pelvis. We need it for upright locomotion. It would be catastrophic if it went away.
It is now widely acknowledged today that these teeth are not rudimentary or vestigial: they aid in chewing our food as do all of our other 28 teeth. The outdated vestigial organ conclusion, though, has influenced the extraction of billions of teeth, the removal of many which may have been unnecessary according to current research.
Third-molar surgery or the removal of the impacted third molars is a multibillion-dollar industry generating significant income for the dental practitioners, particularly oral and maxillofacial surgeons. It is driven by myths and misinformation that have been exposed before but that continue to be propagated by the profession.
Body hair and goose bumps
Androgenic hair provides tactile sensory input by transferring hair movement and vibration via the shaft to sensory nerves within the skin. ... Androgenic hair extends the sense of touch beyond the surface of the skin into the air and space surrounding it, detecting air movements as well as hair displacement from contact by insects or objects.
A hair plexus or root hair plexus is a special group of nerve fiber endings and serves as a very sensitive mechanoreceptor for touch sensation. Each hair plexus forms a network around a hair follicle and is a receptor, which means it sends and receives nerve impulses to and from the brain when the hair moves.
Goosebumps, by causing hairs to stand erect, extend the reach of our tactile sense to it's maximum distance beyond the skin. They also cause the hair shafts to separate which reduces the amount of dampening of movements and vibrations, thus increasing sensitivity to small stimuli.
When a person is confronted with fear or cold, muscle fibers contract in the skin, forming goose bumps. This muscular activity produces heat, and thus raises the body temperature. (source: Marshall Cavendish Illustrated Encyclopedia of Family Health, vol. 19, p. 2052.)
Blood vessels leading to the skin capillaries become narrower - they constrict - letting less blood flow through the skin and conserving heat in the body.
Junk DNA or junk science?
It is a remarkable fact that the greater part (95 per cent in the case of humans) of the genome might as well not be there, for all the difference it makes.
The human genome encodes the blueprint of life, but the function of the vast majority of its nearly three billion bases is unknown. The Encyclopedia of DNA Elements (ENCODE) project has systematically mapped regions of transcription, transcription factor association, chromatin structure, and histone modification. These data enabled us to assign biological functions for 80% of the genome, in particular outside of the well-studied protein-coding regions.
Researchers linked more than 80 percent of the human genome sequence to a specific biological function and mapped more than 4 million regulatory regions where proteins specifically interact with the DNA. These findings represent a significant advance in understanding the precise and complex controls over the expression of genetic information within a cell. The findings bring into much sharper focus the continually active genome in which proteins routinely turn genes on and off using sites that are sometimes at great distances from the genes themselves. They also identify where chemical modifications of DNA influence gene expression and where various functional forms of RNA, a form of nucleic acid related to DNA, help regulate the whole system.
Pseudogenes have long been labeled as "junk" DNA, failed copies of genes that arise during the evolution of genomes. However, recent results are challenging this moniker; indeed, some pseudogenes appear to harbor the potential to regulate their protein-coding cousins. Far from being silent relics, many pseudogenes are transcribed into RNA, some exhibiting a tissue-specific pattern of activation.
Darwin-lover Nick Matzke
Skepticism has arisen spontaneously from all over the scientific blogosphere, facebook, and twitter. You see, most of us scientists know that ENCODE is using an extremely liberal and dubious definition of "function", basically meaning "some detectable chemical activity". ... All the evidence for relative nonfunctionality which has been known for decades is still there and hasn't really changed. ... But I'm beginning to think that certain parts of molecular biology and bioinformatics are populated with people who are very smart, but who got through school with a lot of detailed technical training but without enough broad training in basic comparative biology.