HOME >> BIOLOGY >> NEWS
Natural selection in island sheep

No one knows for sure when or how they got there, but Soay sheep (Ovis aries) arrived on the isolated, wind-swept Scottish island of Soay sometime during the Bronze Age, thousands of years ago. In the 1930s, a flock was relocated to Hirta, an adjacent island in the St. Kilda archipelago, after villagers evacuated to the mainland. Since then, the sheep have been left mostly to their own devices, save for ongoing encounters with scientists keen to test a range of evolutionary hypotheses on this unique population.

Alastair Wilson, Loeske Kruuk, and colleagues took advantage of a 20-year study of birth weight in Soay sheep--which covered nine generations and significant climatic fluctuations--to examine the impact of environmental quality on the strength of selection and the amount of genetic variation associated with a fitness-related trait. They now report--in the open-access journal PLoS Biology--that the extent to which birth weight is heritable--that is, the variance caused by maternal genetic effects--increased along with environmental quality.

Evolution should occur when selection acts on a trait, such as birth weight, that has a genetic basis. Birth weight is closely linked to juvenile mortality, with larger lambs having higher survival and higher fitness. The first six months of life are critical; lamb deaths during this crucial window account for nearly a quarter of all deaths. Even though birth weight has all the raw materials for evolution--a positive correlation between birth weight and survival, and a heritable basis for variation, attributed to maternal genetic effects--previous studies found no evidence for evolution of the trait. Since annual birth weight had not increased over the 20 years, the researchers hypothesized that a variable environment could limit its micro-evolution by limiting heritability, selection, or both. Wilson et al. found evidence that that this is indeed the case.

To study the micro-evolutionary d
'"/>

Contact: Natalie Bouaravong
press@plos.org
415-568-3445
Public Library of Science
12-Jun-2006


Page: 1 2 3

Related biology news :

1. Elsevier partners with National Natural Science Foundation of China
2. Natural compound and exercise boost memory in mice
3. Natural immune-control system may aid treatment of autoimmune disease and tissue rejection
4. Natural anti-freeze -- how arthropods survive the cold
5. Natural mechanism for immune suppression paves way for cancer trials
6. Natural polyester makes new sutures stronger, safer
7. Natural antibiotics yield secrets to atom-level imaging technique
8. Natural fiber may take extra pounds away
9. Natural gut hormone offers hope for new obesity drug
10. Naturally occurring enzyme can break down key part of Alzheimers plaques
11. Natural anti-viral enzyme helps keep cancer cells alive, researchers find

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/4/2019)... ... June 04, 2019 , ... Harper was three years old when her owners ... dysplasia, which caused painful osteoarthritis in the joints. She was referred to a ... , The surgical specialist, Dr. Christopher Eich of Southern California Veterinary Specialty Hospital ...
(Date:6/1/2019)... ... May 31, 2019 , ... The University ... recently invested in BioFactura’s $6M Series B Financing Round. , “With the ... investors who bring significant financial and business resources to bear as we advance ...
(Date:5/31/2019)... (PRWEB) , ... May 30, 2019 , ... Enso Discoveries ... and especially during Military Appreciation Month, as a way to express his gratitude and ... and the company he founded — Enso Discoveries — presented a check ...
Breaking Biology News(10 mins):
(Date:5/22/2019)... ... 2019 , ... Artemis (formerly Agrilyst), the leading enterprise Cultivation Management ... co-led by Astanor Ventures and Talis Capital with participation from ... Fund . The company has raised $11.75m to date and will use the new ...
(Date:5/14/2019)... , ... May 13, 2019 , ... ... helium-based leak testing instruments for the Pharmaceutical, Biotechnology, Medical Device and Food Packaging ... website. The redesigned website aims to improve LDA’s ability to communicate directly with ...
(Date:5/4/2019)... ... May 03, 2019 , ... ... of the Dakila Pesquisas Association, the scientist and ufologist Urandir Fernandes de Oliveira, ... (DF). Urandir detailed the results of some research carried out by the association, ...
(Date:5/2/2019)... ... 2019 , ... Stay on top of current hot topics through free webinars ... all webinars is free, so be sure to register today to save your place! ... to see our upcoming webinars: , CLINICAL TRIALS , May 7 – Oncology ...
Breaking Biology Technology:
Cached News: