|ELEPHANTS LOSE TUSKS “BY EVOLUTION” claim media reports. During the civil war in Mozambique (1977-1992) ivory poachers killed elephants and sold the tusks to finance their war. During this time the population of elephants declined drastically. The elephant population is now making a comeback, but with a change – more female elephants are lacking tusks. Before the war about 18.5% of females were tuskless, but 33% of females born since the war do not have tusks. A group of scientists led by Shane Campbell-Staton and Robert Pringle of Princeton University studied the elephant population of Gorongosa National Park in Mozambique, using records from an elephant conservation organisation and videos taken in the park from before the war. They found tuskless mother elephants had equal numbers of daughters with and without tusks, and had twice as many daughters as sons. They then analysed genomes of the elephants in the park and found the tuskless females carried mutations in two genes named MEP1a and AMELX. The AMELX gene is on the X chromosome, and mutations of it in humans are known to cause defective tooth growth in females and are lethal to males. This pattern of inheritance, known as X-linked dominant, male-lethal, would explain the skewed sex ratio of the tuskless mother’s offspring and the number of tuskless daughters. Putting these genetic and population studies together, the research team, along with all the reports in the news sources, claim the increase in tuskless females is a case of rapid evolution. The research team entitled their research paper “Ivory poaching and the rapid evolution of tusklessness in African elephants”. They summarised their findings as: “This study provides evidence for rapid, poaching-mediated selection for the loss of a prominent anatomical trait in a keystone species”.|
References and Links: Science (AAAS) News 21 October 2021, Nature News 21 October 2021, ABC News 22 October 2021, and Science 22 October 2021, doi: 10.1126/science.abe7389.ED. COM. The summary is correct, but the headlines are all wrong. This is a classic case of selection, but nothing has evolved. Poachers selectively killed elephants with tusks which allowed the already existing tuskless elephants with the tuskless gene to survive, and increase in numbers. But that did not make them evolve. This is unnatural selection at work, but it is no different from legitimate farmers using selective breeding to increase the number of animals that have a desirable trait, such as hornlessness, in farm animals. However, in this case, the increased trait is a defect, since tusks help elephants to push over branches and trees and dig holes as they forage for food and minerals, so loss of them is a negative. Overall, this study is a good reminder that the world has changed, but it has not evolved. It has gone from good to bad to worse – the opposite of evolution, but exactly what the Bible tells us.