Editing Glottochronology (section)

==Methodology==

The original method of glottochronology presumed that the core vocabulary of a language is replaced at a constant (or constant average) rate across all languages and cultures and so can be used to measure the passage of time. The process makes use of a list of lexical terms and morphemes which are similar to multiple languages.

Lists were compiled by Morris Swadesh and assumed to be resistant against borrowing (originally designed in 1952 as a list of 200 items (see, but the refined 100-word list in Swadesh (1955)<ref name="swadesh1955">Swadesh, Morris. (1955). Towards greater accuracy in lexicostatistic dating. ''International Journal of American Linguistics'', ''21'', 121–137</ref> is much more common among modern day linguists). 

The core vocabulary was designed to encompass concepts common to every human language such as personal pronouns, body parts, heavenly bodies and living beings, verbs of basic actions, numerals, basic adjectives, kin terms, and natural occurrences and events.<ref name=":1" /> Through a basic word list, one eliminates concepts that are specific to a particular culture or time period. It has been found through differentiating word lists that the ideal is really impossible and that the meaning set may need to be tailored to the languages being compared. Word lists are not homogenous throughout studies and they are often changed and designed to suit both languages being studied. Linguists find that it is difficult to find a word list where all words used are culturally unbiased.<ref name=":2" /> Many alternative word lists have been compiled by other linguists and often use fewer meaning slots.

The percentage of [[cognate]]s (words with a common origin) in the word lists is then measured. The larger the percentage of cognates, the more recently the two languages being compared are presumed to have separated.

===Glottochronologic constant===
Determining word lists rely on morpheme decay or change in vocabulary. Morpheme decay must stay at a constant rate for glottochronology to be applied to a language. This leads to a critique of the glottochronologic formula because some linguists argue that the morpheme decay rate is not guaranteed to stay the same throughout history.<ref name=":2" />

American Linguist [[Robert Lees (linguist)|Robert Lees]] obtained a value for the "glottochronological constant" ('''r''') of words by considering the known changes in 13 pairs of languages using the 200 word list.  He obtained a value of 0.8048&nbsp;±&nbsp;0.0176 with 90% confidence. For his 100-word list Swadesh obtained a value of 0.86, the higher value reflecting the elimination of semantically unstable words. 

===Divergence time===
The basic formula of glottochronology proposed by [[Morris Swadesh]] is:

: <math> t = -\frac{\ln(c)}{2\ln(r)}</math>

''t'' = a given period of time from one stage of the language to another (measured in millennia),<ref>{{cite book |last1=McMahon |first1=April |last2=McMahon |first2=Robert |title=Language Classification by Numbers |date=2005 |publisher=OUP Oxford |isbn=9780191535369 |page=180}}</ref> ''c'' = proportion of wordlist items retained at the end of that period and ''r'' = rate of replacement for that word list.

By testing historically verifiable cases in which ''t'' is known by nonlinguistic data (such as the approximate distance from Classical Latin to modern Romance languages), Swadesh arrived at the empirical value of approximately 0.14 for ''L'', (''c''?) which means that the rate of replacement constitutes around 14 words from the 100-wordlist per millennium. This is represented in the table below.

{| class="wikitable"
|+ Glottochronology Time Scale
|-
! Rough Median Dating !! Median Cognate Retention in 100-Word List
|-
| 500 BP || 86%
|-
| 1000 BP || 74%
|-
| 1500 BP || 64%
|-
| 2000 BP || 55%
|-
| 2500 BP || 47%
|-
| 3000 BP || 40%
|-
| 4000 BP || 30%
|-
| 5000 BP || 22%
|-
| 6000 BP || 16%
|-
| 7000 BP || 12%
|-
| 8000 BP || 9%
|-
| 9000 BP || 7%
|-
| 10000 BP || 5%
|}


===Results===
Glottochronology was applied to a range of language families, including [[Salishan]],<ref>{{Cite journal|last=Swadesh|first=Morris|date=Oct 1950|title=Salish Internal Relations|url=https://www.jstor.org/stable/1262898|journal=International Journal of American Linguistics|volume=16|pages=157–167|doi=10.1086/464084 |jstor=1262898 |s2cid=145122561 }}</ref> [[Indo-European]],<ref name="q259">{{cite journal | last=Arndt | first=Walter W. | title=The Performance of Glottochronology in Germanic | journal=Language | volume=35 | issue=2 | date=1959 | pages=180–192 | doi=10.2307/410532 | jstor=410532 }}</ref> [[Japonic]],<ref name="b357">{{cite journal | last=Hattori | first=Shiro | title=A Glottochronological Study on Three Okinawan Dialects | journal=International Journal of American Linguistics | volume=27 | issue=1 | date=1961 | issn=0020-7071 | doi=10.1086/464603 | pages=52–62}}</ref> [[Afro-Asiatic]],<ref name="b524">{{cite book | last=Fleming | first=Harold C. | title=Lexicostatistics in Genetic Linguistics | chapter=SUB-CLASSIFICATION IN HAMITO-SEMITIC | publisher=De Gruyter | date=1973-12-31 | isbn=978-3-11-088084-7 | doi=10.1515/9783110880847-007 | pages=85–88}}</ref> [[Chinese language | Chinese]]<ref name="y152">{{cite journal | last=Munro | first=Stanley R. | title=Glotto chronologic theory: Valid or not in Chinese languages? | journal=Canadian Journal of Linguistics | volume=23 | issue=1–2 | date=1978 | issn=0008-4131 | doi=10.1017/S0008413100008707 | pages=55–65}}</ref> and [[Amerind languages|Mayan]] and other American languages.<ref name="l956">{{cite book | last=Stark | first=Louisa R. | title=Lexicostatistics in Genetic Linguistics | chapter=GLOTTOCHRONOLOGY AND THE PREHISTORY OF WESTERN SOUTH AMERICA | publisher=De Gruyter | date=1973-12-31 | isbn=978-3-11-088084-7 | doi=10.1515/9783110880847-009 | pages=100–107}}</ref> 

For Amerind, correlations have been obtained with radiocarbon dating and blood groups{{dubious|date=January 2022}} as well as archaeology.{{citation needed|date=January 2022}}<!--Amerind blood group is 0, so... -->


=== Example Wordlist  ===

Below is an example of a basic word list composed of basic Turkish words and their English translations.<ref>{{Cite journal|last=Pierce|first=Joe E.|date=Feb 1996|title=Glottochronology and the Turkish Basic Vocabulary|journal=American Anthropologist|volume=68|issue=1 |pages=137–143|doi=10.1525/aa.1966.68.1.02a00150 |jstor=668071 |doi-access=free}}</ref>
{| class="wikitable"
|+Glottochronological Turkish 100 Word List
|hep (all)
|ateş (fire)
|boyun (neck)
|bu (that)
|-
|kül (ashes)
|balık (fish)
|yeni (new)
|şu (this)
|-
|kabuk (bark)
|uçmak (fly)
|gece (night)
|sen (thou)
|-
|karın (belly)
|ayak (foot)
|burun (nose)
|dil (tongue)
|-
|büyük (big)
|vermek (give)
|bir (one)
|diş (tooth)
|-
|kuş (bird)
|iyi (good)
|kişi (person)
|ağaç (tree)
|-
|ısırmak (bite)
|yeşil (green)
|yağmur (rain)
|iki (two)
|-
|kara (black)
|saç (hair)
|kızıl (red)
|yürümek (walk)
|-
|kan (blood)
|el (hand)
|yol (road)
|sıcak (warm)
|-
|kemik (bone)
|baş (head)
|kök (root)
|su (water)
|-
|yakmak (burn)
|duymak (hear)
|kum (sand)
|biz (we)
|-
|bulut (cloud)
|gönül (heart)
|demek (say)
|ne (what)
|-
|soğuk (cold)
|ben (I)
|görmek (see)
|beyaz (white)
|-
|gelmek (come)
|öldürmek (kill)
|tohum (seed)
|kim (who)
|-
|ölmek (die)
|bilmek (know)
|oturmak (sit)
|kadın (woman)
|-
|köpek (dog)
|yaprak (leaf)
|deri (skin)
|sarı (yellow)
|-
|içmek (drink)
|yalan (lie)
|uyumak (sleep)
|uzun (long)
|-
|kuru (dry)
|ciğer (liver)
|küçük (small)
|yok (not)
|-
|kulak (ear)
|bit (louse)
|duman (smoke)
|göğüş (breast)
|-
|yer (earth)
|erkek (man-male)
|ayaktakalmak (stand)
|hayvan tırnagı (claw)
|-
|yemek (eat)
|çok (many)
|yıldız (star)
|dolu (full)
|-
|yumurta (egg)
|et (meat-flesh)
|taş (stone)
|boynuz (horn)
|-
|göz (eye)
|dağ (mountain)
|güneş (sun)
|diz (knee)
|-
|yağ (fat-grease)
|ağız (mouth)
|yüzmek (swim)
|ay (moon)
|-
|tüy (feather)
|isim (name)
|kuyruk (tail)
|yuvarlak (round)
|}