Life is delightful and mysterious! We are publishing a list of impressive riddles that we have not yet come close to solving.
1. Cows, when grazing, always look north or south
Scientists recently uncovered a detail that has been overlooked for millennia: cows, while resting or grazing, stand along the Earth's magnetic poles, head north or south. The circuit remains the same regardless of wind or other factors, and no one really knows why.
2. Why did some mammals return to the water?
We know that sea animals came out of the water and they got limbs that allow them to move on land. This was a wise move, as the earth contained a large amount of resources, ideal for successful evolution. But why some of these animals, such as the ancestors of whales or seals, returned back to the water remains unknown.
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3. Alkaloids in plants
Alkaloids are naturally occurring compounds found in plants, the most common of which is morphine. Alkaloids have a special ("narcotic") effect on animals and people. And although we have studied them in some detail, we still do not fully understand why plants need them.
4. Why are flowers everywhere?
Flowering plants form the angiosperm class, and as you may have noticed, they are everywhere. Surprisingly, this was not always the case. Flowering plants about 400 million years ago supplanted other types of plants in a short period of time, and as a result, today they account for about 90% of all plant species.
This problem worried Charles Darwin so much that he called it "a terrible secret."
5. Why is there such diversity around the equator?
About 200 years ago, Prussian explorer Alexander von Humboldt first discovered that biodiversity increases as you get closer to the equator. Nature and human culture are becoming more diverse and vibrant, as are diseases.
There are about three dozen theories trying to find an answer to this question, but there is still no consensus among scientists.
6. The phytoplankton paradox
Phytoplankton is a class of organisms found in large bodies of water and includes a wide range of different subspecies. This is an extremely diverse group, and the diversity of these organisms challenges evolution and natural selection. Lack of resources makes it impossible for such a large number of different organisms to survive in an ecosystem without destroying each other. But somehow they exist.
7. How Argentine ants create colonies on different continents
Argentine ants are the only species other than humans that have managed to colonize three continents. All three supercolonies of Argentine ants in Europe, South America and Asia are composed of ants, which are essentially one population. Ants immediately recognize their brothers every time they get around, but are aggressive with ants of other species. This is strange, to put it mildly, given the vast distances that supercolonies separate.
8. The mysterious ancestor of man
When scientists examined the DNA of Denisovan man (Denisovan is a species of fossil man closely related to Neanderthals and named after the caves in which it was first found), they found traces of a mysterious species that science has not been able to identify. Although the Denisovan is also surrounded by mystery, we at least know who he was and where he came from. However, the same cannot be said about the unknown species with which they bred about 30,000 years ago and which left a clear trace in the DNA of the Denisovan. All we know is that they gave the Denisovan man a set of teeth not found anywhere else in the animal kingdom.
9. Animals that can live without oxygen
Everyone was shocked when anoxic animals were found deep in the Mediterranean Sea. Among complex multicellular animals, this is unheard of. Loricifer-type creatures, very small animals, once lived in the air, but eventually adapted to a new environment in which oxygen was replaced by salts.
Science is unaware of other complex organisms living in an oxygen-free environment, and we have no idea of their evolutionary history.
10. Sexual reproduction
With the exception of some microbes and plants, almost all life in the world reproduces sexually. If you think about it, this is a huge evolutionary anomaly. Half of the species - males - are unable to produce offspring using the same amount of resources from the environment as females. Why would it take so much effort to develop a mechanism that looks like a clear flaw?.. Unknown.