In her large-scale study, Canadian zoologist Sara Otto talks about the influence of mankind on global evolution, emphasizing that the problem is not only harm, but also in the low awareness of mankind about its influence on nature.
“The rate at which the biotic and abiotic environment of species has changed has already influenced the evolutionary trajectory of animal species, and this trend is only promising to increase,” Otto says in a recent article for Proceedings of the Royal Society B.
Changing course for ecosystems is not new. About 90 percent of all species that lived on Earth followed the example of the dodo bird (an extinct flightless bird from the monotypic genus Raphus), which led to a change in the characteristics of the biosphere.
A hundred years ago, the world's population was approximately 1.8 billion. Now this number is approaching 7.6 billion, increasing by an average percentage annually. And the problem is not only the growing demand for food, but also the impact of each individual on the natural landscape - this mark is growing by 0.5 percent every year.
Large numbers of people, with their impact on the environment, have led to an exponential increase in devastation, the global rate of extinction and the extinction of a significant number of animal species during one human life.
On average, human activities have removed eight percent of the carbon from two meters of the topsoil, increased atmospheric temperatures by nearly 1 ° C, and lowered the pH of the oceans by about 0.1. This influence is not only monumental in scale but unprecedented in speed.
By changing the landscape with new buildings, we affect how animals move, plants grow and microbes multiply, which, in turn, affects the survival or extinction of the species. For example, the wingspan of rocky swallows evolved to be shorter near highways, as their habitual wingspan provoked death from traffic.
We've also changed the organisms' habitat by replanting species, hunting animals of the right size, or uprooting weeds and fighting “pests” that can affect yields. However, along with all the destruction, humans also made a reasonable contribution to increasing genetic diversity - whether it was dividing populations into parts or creating new conditions for species.
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This all leads to the question of biodiversity balance over time. Is there some kind of large-scale equilibrium to be reached in this new evolutionary landscape? Or does human activity inevitably lead to increasing difficulties? To these questions, according to Otto, science has no answer. The scientist notes that the news regarding the state of the environment is not always pleasant, but the fact that we still know so little about our impact on the planet is something that is really worth worrying about.
Dmitry Mazalevsky