Insects 250,000 years ago challenge evolution


Researchers at the University of Melbourne have discovered that the current understanding of evolution may be incorrect after studies of ancient Australian grasshopper species reveal new insights into the animal kingdom.

Researchers have found that W. virgo, which employs parthenogenesis (a form of reproduction by females of a species capable of growing an egg into an embryo without fertilization), is as successful as its sexually reproducing relatives. Did.

Professor Michael Kearney, lead author of the research paper, said at the University of Melbourne: news release The results of the study are important because they challenge the current understanding of evolution. As it is today, evolution suggests that sexual reproduction has an advantage over parthenogenesis.

“Most species on Earth have two sexes, male and female, and mix genes during reproduction. This breeding method is thought to enhance the genetic diversity and ecological success of the species. “We do,” Kearney said.

“Theoretically, parthenogenetic species should suffer from parasites and large numbers of bad mutations. In our study, we have a disadvantage to W. virgo compared to other types of sexually reproducing species. There is no point. “

“In fact, W. virgo, unlike sexual relatives, could even spread well from west to east of Australia.”

Professor Ary Hoffmann, co-author of the paper, also noted that breeding through male-female interactions can be costly.

“Finding a companion takes time and effort and increases the risk of predation. If we eliminate males, still have viable offspring and the species are thriving, why are we having sex? Are you not bothered at all? “Hoffman said.

Epoch Times Photo
There are several parthenogenetic species in Australia. (Global grass hopper)

The purpose of sexual reproduction in evolution

W. Virgo is green “Match stick” grasshopper— A wingless subfamily of grasshoppers — Native to Australia and limited to Australia. It contains about 250 species and is named after its matchstick-like appearance.

Kearney, in an email to the Epoch Times, theorized that successful grasshopper-type clones develop a tendency for bad mutations and parasites because they are unable to shuffle genes through male and female reproduction. Said that there is. The inability to shuffle genes means that the environment of the species may change over time and may not be able to continue to evolve.

“Parasitic worms and diseases can evolve rapidly, and one idea of ​​sexual benefits is to allow species to rapidly evolve new defenses against them.”

Another problem with cloning, Kearney, said mutations continue to grow in a “ratchet-like way.”

“Sexual reproduction can combine two different bad mutations into one individual, and when that individual dies, the mutations are lost from the gene pool,” he said.

“Parthenogenetic species cannot do this, so they accumulate a load of bad mutations faster. In the very long term, these problems may be expected to become parthenogenetic problems. not.”

“But in the grasshoppers we studied, there was still no evidence that this was happening, even though its age was estimated to be 250,000,” he continued.

Epoch Times Photo
Blue-footed boobs perform mating rituals. (Colossus Productions / nWave Pictures)

History of Warama Babago

Researchers examined more than 1500 genetic markers of W. virgo to assess the genetic diversity of the species and found that there was little change compared to sexually reproducing relatives. ..

“This species seems to have originated only from a single, very successful clone,” he said.

A Tracking paper Based on the number and nature of mutations accumulated in grasshoppers, written by Kearney and Hoffman, the team said the team estimated that the clone was created about 250,000 years ago. The absence of change in W. Virgo indicates that this species was created by a unique case of interspecific breeding between W. whitei grasshoppers and W. flavolineata grasshoppers.

The research team has been studying this species for 18 years, and the study of this batta has been underway since 1962, when it was discovered by Professor Michael White, the son of a biologist and geneticist. White’s son Nicholas found a grasshopper near the town of New South Wales in Hillston and told his father that no man was found.

White confirmed that the species was parthenogenetic and that the species was located in Western Australia, 2000 km from Hilston.

This species inhabits the southern part of Australia’s arid regions and feeds on native plants such as Marga trees and other shrubs and bushes in the summer.

Remote Kimberley region in northwestern Australia.
Remote Kimberley region in northwestern Australia. (Provided by Wal-Mart)

Why sexual reproduction is so common

There are several species that propagate through parthenogenesis in Australia, but parthenogenetic species are generally very rare.

“Our research suggests that this rarity is most likely due to origin constraints rather than rapid extinction,” Kearney said.

The researchers are W. W. by breeding whitei and W. flavolineata together. Attempted breeding of virgo, but the hybrids created did not develop parthenogenesis. Kearney and Hoffman stated that parthenogenesis can be a very rare phenomenon. This is because the hybrid state is sufficient to interfere with normal egg development.

however, paper He suggests another explanation in the conversation, suggesting that the reason why parthenogenesis is so rare is due to the sedentary nature of sexual reproduction. In this article, I’ve talked about the less common possibilities because sexual reproduction is a better strategy, but once it’s developed, it’s difficult to get rid of the process.

Epoch Times Photo
It is unlikely that human parthenogenesis will become a reality. (Jacob Lund / Shutterstock)

Parthenogenesis with humans

Human males are comfortable breathing, even though grasshoppers precede males. Homo sapien parthenogenesis is very unlikely to become a reality.

Kearney said mammals are less likely to reproduce asexually than insects because of what is called “genomic imprinting.” He said that genomic imprinting is where certain genes are not switched on unless they are in the female environment, and other genes are not switched on unless they are in the male environment.

“Therefore, not all genes required for successful development are turned on, so it is not possible to develop an embryo by parthenogenesis from a single or two fused eggs,” Kearney said. Mr. says.

“It is not clear why genomic imprinting has evolved, but it acts as an integrated” protection “from the evolution of parthenogenesis. “

In addition, Kearney and Hoffman said that future research on sexual reproduction needs to look for something that prevents the loss of sexual reproduction, not purely its benefits.

The results of the study were published in the journal, Chemistry..

Lily Kelly


Lily Kelly is an Australian-based reporter of The Epoch Times, dealing with social issues, renewable energy, the environment, health and science.