Study: Did Parasites play a role in the evolution of sex?

admin — Mon, 14 Dec 2009 22:31:11 +0000

It’s almost hard to believe, but there is a new theory that suggests that sex between humans may have evolved as a defense against parasites. It sounds a bit far-fetched, but below is the hypothesis that scientists are currently discussing and recently published in the July 09 issue of American Naturalist.

The theory presented in the study:

One hypothesis is that parasites keep asexual organisms from getting too plentiful. When an asexual creature reproduces, it makes clones—exact genetic copies of itself. Since each clone has the same genes, each has the same genetic vulnerabilities to parasites. If a parasite emerges that can exploit those vulnerabilities, it can wipe out the whole population. On the other hand, sexual offspring are genetically unique, often with different parasite vulnerabilities. So a parasite that can destroy some can’t necessarily destroy all. That, in theory, should help sexual populations maintain stability, while asexual populations face extinction at the hands of parasites.

Enter Potamopyrgus antipodarum, a snail common in fresh water lakes in New Zealand. What makes these snails interesting is that there are sexual and asexual versions. They provide scientists with an opportunity to compare the two versions side-by-side in nature.

“The rise and fall of these female-only lineages was surprisingly fast and consistent with the prediction of the parasite hypothesis for sex,” Jokela said. “These results suggest that sexual reproduction provides an evolutionary advantage in parasite rich environments.”

Read the full text for more information

Are you confused by this theory? Yeah, we are too. But if this theory does hold up, then it is just one more example as to how some parasites are beneficial to the human body. Of course, we all know that if you have parasites in your intestines, you want to get them out as soon as you possibly can.

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Study: Gut Parasites May Be Widespread In Domestic & Wild Animals

admin — Tue, 08 Dec 2009 21:53:10 +0000

source

According to a recent study, many common protozoans living in the human gut are extremely contagious, and likely to be widespread in many animal species, causing unsettling digestive disorders.

The study was conducted by the Norwegian School of Veterinary Science, in early 2009. They found that parasites of the groups Cryptosporidium and Giardia are enormously widespread in domestic animals, such as dogs, cats and piglets, as well as many wild deer species and the red fox in Norway. These animals are all suffering from different digestive disorders, similar to what humans face when infected with the same kinds of intestinal parasites.

From the study:

Giardia was more common than Cryptosporidium in calves, and the occurrence of both parasites varied with the calves’ age, geographic occurrence, season, and the cleaning frequency of pens. Among wild deer species, Giardia was more common than Cryptosporidium, while roe deer and elk had the highest occurrences of both parasites.

The presence of Cryptosporidium and Giardia in dogs varied with age and geographic location. There was a higher occurrence of diarrhoea in piglets from litters that were infected by Cryptosporidium than in litters free of infection. The occurrence of both parasites was low in the red fox, however, the geographic distribution was extensive.

The results of these studies show that parasites of the groups Cryptosporidium and Giardia are widely distributed among both domestic and wild animals in Norway. Grazing animals may represent a source of transmission to man through drinking water, although people can also become infected through direct contact with infected animals.

Read the entire study for more information

What You Can Do To Protect Yourself

The fact of the matter, is there are many different kinds of intestinal parasites that can affect humans. This new study points out that these same parasites can be spread to animals. Remember to wash your food thoroughly and only drink purified water. If the food or water you consume is contaminated, there is a good chance a parasite could develop in your gut.

If you think you are suffering from symptoms of parasites, then you should see your doctor immediately. He will most likely give you a prescription that will help kill off the parasite within a few weeks. If you don’t want to take prescribed medicine, then you can always look into doing a parasite cleanse or taking an herb that will kill them off as well. There are many herbs that help promote a healthy intestinal tract. Just remember to get organically-certified herbs, if possible.