Microevolution refers to the small changes that occur within a species over a short period of time, typically within a single generation. On the other hand, macroevolution involves the significant changes that take place in a species over a long period of time, spanning multiple generations.
To put the concept of time into perspective, if we were to condense Earth’s 4.5 billion-year existence into 24 hours, each minute would represent over 3 million years. For example, the extinction of dinosaurs would occur at 11.39 pm and 48 seconds, and human history would start just before midnight.
Although the timescales of the universe’s history are vast, it took some time for humans to comprehend the immense age of the Earth. Initially, it was widely believed to be only a few thousand years old, despite evidence from pioneers of geology and evolutionary biology demonstrating its true ancient nature.
Charles Darwin, the renowned scientist, recognized the need for immense periods of time to account for the gradual transformation of species. He explained in his book “On the Origin of Species” that these slow changes cannot be observed until significant time has passed.
For a long time, scientists believed that the rate of evolution was too slow to explain the high levels of biodiversity observed in the world. However, over the past 30 years, research has shown that evolution can occur much more rapidly over shorter timescales than previously thought.
According to Matthew Pennell from the University of British Columbia, evolution over small timescales is now considered to be too fast to fully explain the patterns of diversity observed over longer timescales. This discovery has brought about a shift in understanding the pace and mechanisms of evolution.
