Polycephaly

Article summary

, c. 1881 Polycephaly is the condition of having more than one head. The term is derived from the Greek stems poly (Greek: "πολύ") meaning "many" and kephalē (Greek: "κεφαλή") meaning "head". A polycephalic organism may be thought of as one being with a supernumerary body part, or as two or more beings with a shared body. Two-headed animals (called bicephalic or dicephalic) and three-headed (tricephalic) animals are formed by the same process as conjoined twins from monozygotic twin embryos. In humans, there are two forms of twinning that can lead to two heads being supported by a single torso. In dicephalus parapagus dipus, the bodies are joined at the sides and the two heads are separate. In craniopagus parasiticus, the two heads are joined directly to each other, but only one head has a functional ‌in most cases, this manifests as an underdeveloped twin head joined to the head of a developed twin. Documented survival into childhood is extremely rare. Survival to adulthood is rare, but does occur in some forms of dicephalus parapagus dipus, as was reported in a case of dicephalic twin born at 36 weeks of gestation to a multigravida mother in central India. There are many occurrences of multi-headed animals in mythology. In heraldry and vexillology, the double-headed eagle is a common symbol, though no such animal is known to have ever existed.

Key claims

1. date of birth: 1875 — source: Wikipedia · confidence 0.95
2. date of birth: 1990 — source: Wikipedia · confidence 0.95
3. date of birth: 2000 — source: Wikipedia · confidence 0.95
4. date of birth: 1990 — source: Wikipedia · confidence 0.95
5. date of birth: 2006 — source: Wikipedia · confidence 0.95
6. date of birth: 2009-02-13 — source: Wikipedia · confidence 0.95
7. date of birth: 1997 — source: Wikipedia · confidence 0.95
8. date of birth: 2013-06-18 — source: Wikipedia · confidence 0.95
9. date of birth: 2015 — source: Wikipedia · confidence 0.95
10. date of death: 2007 — source: Wikipedia · confidence 0.95
11. date of death: 2006 — source: Wikipedia · confidence 0.95
12. date of death: 2008-04-30 — source: Wikipedia · confidence 0.95
13. date of death: 2009-08-28 — source: Wikipedia · confidence 0.95
14. date of death: 2006 — source: Wikipedia · confidence 0.95
15. publication date: 1734 — source: Wikipedia · confidence 0.95

Discussion questions

1. Summarise the article in your own words. Which single claim would you verify first, and why?
2. The record states that the date of birth is "1875". What evidence would count against this claim?
3. The record states that the date of birth is "1990". What evidence would count against this claim?
4. The record states that the date of birth is "2000". What evidence would count against this claim?
5. The record states that the date of birth is "1990". What evidence would count against this claim?
6. The record states that the date of birth is "2006". What evidence would count against this claim?
7. The record states that the date of birth is "2009-02-13". What evidence would count against this claim?
8. The record states that the date of birth is "1997". What evidence would count against this claim?
9. The record states that the date of birth is "2013-06-18". What evidence would count against this claim?
10. The record states that the date of birth is "2015". What evidence would count against this claim?
11. The record states that the date of death is "2007". What evidence would count against this claim?
12. The record states that the date of death is "2006". What evidence would count against this claim?
13. The record states that the date of death is "2008-04-30". What evidence would count against this claim?
14. The record states that the date of death is "2009-08-28". What evidence would count against this claim?
15. The record states that the date of death is "2006". What evidence would count against this claim?
16. The record states that the publication date is "1734". What evidence would count against this claim?
17. Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
18. If two sources disagreed about one of these facts, what would you need in order to trust one over the other?

Bibliography

1. Wikipedia https://en.wikipedia.org/w/index.php?oldid=1378887536