Evolution is considered a long and slow process, especially when new species are formed.
Ever since Charles Darwin and other scientists in the 19th century drafted the theory of evolution, biologists have studied and partially uncovered this mysterious process. This process has endowed the planet with the amazing biodiversity we witness today. However, we still don't fully understand the complex mechanisms that drive the formation of new species, and until recently, it was known that new species will emerge quickly when conditions are right.
Darwin
For the first evolutionary biologists such as Darwin and Alfred Russell Wallace, the emergence of new species was mainly visible on land scales. They observed that populations that were far apart and separated for a long time adapted to their environment in different ways and took different evolutionary paths. Due to the lack of tools, and even the lack of genetic knowledge, evolution is a process that can only be seen with the naked eye. Darwin learned that birds on several islands in the Galapagos Archipelago looked similar to each other, similar to birds on the American continent, but showed some key differences, such as the size of their beaks. This helped him come up with the idea of changing species through natural selection and adapting to new environments. But in the absence of geographical barriers and through forces different from natural selection, it is difficult to explain how new species arose.
Ever since Gregor Mendel developed the principles of genetics by growing peas in the monastery gardens, evolutionary research has taken a huge step forward. Today, thanks to huge advances in science and technology, we can sequence entire genomes in a matter of days at affordable prices, grow thousands of cells simultaneously in the lab, and even do crazy things that were completely unimaginable 15 years ago. Now we can witness the larger and larger evolution that Darwin and Wallace observed with the naked eye. Now, more than ever, we recognize truly ubiquitous and diverse evolution.
Mendel pea experiment
Research group at the University of Ludwig-Maximilians-Universität in Munich. The process of speciation was studied through a very interesting group of locusts of the genus Chorthippus. These different species look very similar, making it nearly impossible for biologists to distinguish them based on their appearance. The species coexists in large areas of Europe, even on the same grassland, making this distinction more challenging. However, taxonomists classify males into different species based on their unique mating songs. However, recent studies have questioned whether people can correctly classify locusts in the genus Locust. First, the researchers found that the species was forced to mate in the lab and produce healthy hybrid offspring. If these animals are carried out in the wild, one could say that they are just a species with multiple song variants. Second, phylogenetic studies of locusts in the genus Locust have shown that locusts belonging to different species are presumed to be genetically closely linked to the exclusion of them in different populations. The study is based on only a small fraction of the giant locust genome.
The juvenile locust is a locust genus
Given these different findings, there are two possible scenarios for the evolutionary history of locusts in the genus Locust. One of them is that they cross in the wild and cannot be considered different species. Another possibility is that different species formed so closely that they had not yet reached the stage of reproductive isolation, and there was not yet enough genetic divergence to detect them with small-scale genetic studies. If the latter case is true, a barrier must exist to prevent different species from mating in nature. The species can be found in the same meadows of Central and Western Europe, and therefore unlike the finches of Darwin, it is not geographical or ecological that separates them. The best way to distinguish between males is different mating songs: if females evolve to choose only partners who sing their own songs, they may interbreed forever or rarely. This results in the isolation of different song groups in the same physical space. Now, it is necessary to find out which of these two possibilities is correct.
3 different genera of locusts
Although research on this particular problem will be based entirely on computers, the researchers went to the field, the Pyrenees. The plan was to travel from Munich all the way to the Franco-Spanish border to catch two species of locusts that coexisted. A few days later, a total of 250 singing locusts were captured.
Field trips
After a small field expedition, it's time to start real research. Doing genetic research today requires a lot more preparation on computers than one might think. The lab has completed the work of extracting DNA from animal tissues and sequencing it, and now needs to classify, clean up and standardize the genetic information uploaded to the Internet by different scientists around the world. Eventually, the researchers seem to have figured out the story between the two types of locusts.
Catch locusts
Surprisingly, even though they are a few centimeters apart from each other and can mate perfectly, locusts of the genus Locust do not seem to do so. Their genetic code tells us that different species are cleanly separated and show no signs of hybridization at all. These locust species are very "young" and are most likely to have appeared during or after the last ice age, the most recent 12,000 years ago. At this time in history, humanity was already developing agriculture and establishing the first settlements. On evolutionary timescales, these species formed in seconds. As for why the locusts of the genus Locust produce different songs and evolve into different species, the answer is unclear. One possibility is that in the past they were physically isolated, such as during ice ages in different living areas, and once the ice disappeared, they met. It is also possible that the species began to diversify only as it expanded into emerging European territories. The fascinating thing about these little locusts is that, despite their young age and great similarities, they maintain a very clear reproductive isolation – which is produced by the search for a partner – and not directly caused by survival in the new environment.