scholarly journals Genetics, Linguistics and the ‘Serial Founder Effect’. A Case Study

2016 ◽  
Vol 38 (1) ◽  
pp. 141-158
Author(s):  
Federico Albano Leoni
Keyword(s):  
Founder Effect ◽  
Serial Founder Effect

scholarly journals Cooperation mitigates diversity loss in a spatially expanding microbial population

2019 ◽  
Vol 116 (47) ◽  
pp. 23582-23587 ◽  
Author(s):  
Saurabh R. Gandhi ◽  
Kirill S. Korolev ◽  
Jeff Gore
Keyword(s):  
Genetic Drift ◽  
Founder Effect ◽  
Microbial Population ◽  
Growth Dynamics ◽  
Low Density ◽  
Drastic Reduction ◽  
Diversity Loss ◽  
Abrupt Changes ◽  
Expanding Population ◽  
Serial Founder Effect

The evolution and potentially even the survival of a spatially expanding population depends on its genetic diversity, which can decrease rapidly due to a serial founder effect. The strength of the founder effect is predicted to depend strongly on the details of the growth dynamics. Here, we probe this dependence experimentally using a single microbial species, Saccharomyces cerevisiae, expanding in multiple environments that induce varying levels of cooperativity during growth. We observe a drastic reduction in diversity during expansions when yeast grows noncooperatively on simple sugars, but almost no loss of diversity when cooperation is required to digest complex metabolites. These results are consistent with theoretical expectations: When cells grow independently from each other, the expansion proceeds as a pulled wave driven by growth at the low-density tip of the expansion front. Such populations lose diversity rapidly because of the strong genetic drift at the expansion edge. In contrast, diversity loss is substantially reduced in pushed waves that arise due to cooperative growth. In such expansions, the low-density tip of the front grows much more slowly and is often reseeded from the genetically diverse population core. Additionally, in both pulled and pushed expansions, we observe a few instances of abrupt changes in allele fractions due to rare fluctuations of the expansion front and show how to distinguish such rapid genetic drift from selective sweeps.

scholarly journals An Ayurvedic approach to the Treatment of Ataxia – A case study

2020 ◽  
Vol 6 (2) ◽  
pp. 69-72
Author(s):  
Vd. Jasminbegam B Momin ◽  
◽  
Vd. PV Kulkarni ◽  
Vd. VE Gogate ◽  
◽  
...  
Keyword(s):  
Spinocerebellar Ataxia ◽  
Founder Effect ◽  
Autosomal Dominant ◽  
Place Of Birth ◽  
Routine Work ◽  
Progressive Cerebellar Ataxia ◽  
Ayurvedic Treatment ◽  
Visual Blurring ◽  
Symptoms And Signs

Progressive Cerebellar Ataxia inherited by autosomal dominant transmission is known as ‘Spinocerebellar Ataxia’ (SCA) which is a neurological disorder. The global prevalence of ataxia is 0.3 – 2 per 1,00,000 population. The prevalence varies significantly depending on the race, place of birth and founder effect. The symptoms and signs of ataxia consists of gait impairment, unclear speech, visual blurring due to nystagmus, poor co – ordination and tremors with the movements. This leads to the dependency of the patient on the others for routine work. In the present study, a case previously diagnosed as spinocerebellar ataxia treated with Ayurvedic treatment is reported. A 55years old female patient having complaints of imbalance while walking, giddiness, unclear speech, poor co-ordination and tremors was treated with Shalishashtik Pinda Sweda over extremities, Nasya with Ksheerbala Taila, Shirodhara and Padabhyanga with Tila Taila and Baladi Niruha Basti (enema) for 28days. Along with these karma, internal medicines were also given.

scholarly journals Can a linguistic serial founder effect originating in Africa explain the worldwide phonemic cline?

2016 ◽  
Vol 13 (117) ◽  
pp. 20160185 ◽  
Author(s):  
Joaquim Fort ◽  
Joaquim Pérez-Losada
Keyword(s):  
Numerical Simulations ◽  
Range Expansion ◽  
Founder Effect ◽  
Linguistic Diversity ◽  
Unit Area ◽  
Accumulation Rate ◽  
Out Of Africa ◽  
Serial Founder Effect

It has been proposed that a serial founder effect could have caused the present observed pattern of global phonemic diversity. Here we present a model that simulates the human range expansion out of Africa and the subsequent spatial linguistic dynamics until today. It does not assume copying errors, Darwinian competition, reduced contrastive possibilities or any other specific linguistic mechanism. We show that the decrease of linguistic diversity with distance (from the presumed origin of the expansion) arises under three assumptions, previously introduced by other authors: (i) an accumulation rate for phonemes; (ii) small phonemic inventories for the languages spoken before the out-of-Africa dispersal; (iii) an increase in the phonemic accumulation rate with the number of speakers per unit area. Numerical simulations show that the predictions of the model agree with the observed decrease of linguistic diversity with increasing distance from the most likely origin of the out-of-Africa dispersal. Thus, the proposal that a serial founder effect could have caused the present observed pattern of global phonemic diversity is viable, if three strong assumptions are satisfied.

scholarly journals Comment on "Phonemic Diversity Supports a Serial Founder Effect Model of Language Expansion from Africa"

Science ◽  
2012 ◽  
Vol 335 (6072) ◽  
pp. 1042-1042 ◽  
Author(s):  
T. F. Jaeger ◽  
D. Pontillo ◽  
P. Graff
Keyword(s):  
Founder Effect ◽  
Effect Model ◽  
Serial Founder Effect
Sign in / Sign up

Export Citation Format

Share Document