Natural Selection
Evolution occurs through natural selection, where organisms with advantageous traits survive and reproduce more successfully than others. These beneficial traits pass to offspring, becoming more common in populations over time. Environmental pressures like predation, resource competition, and climate changes drive selection. This process, first described by Darwin, explains how species adapt to changing conditions.
Genetic Variation
Evolution requires genetic diversity within populations, created through mutation, genetic recombination, and gene flow between populations. Random mutations provide new traits for selection to act upon. Sexual reproduction combines parental genes in new ways, while population mixing introduces additional variation. Some variations improve survival chances, while others may be neutral or harmful.
Speciation Development
New species form when populations become reproductively isolated, often due to geographic barriers or behavioral differences. Over time, separate populations accumulate distinct genetic changes through natural selection and genetic drift. This process can lead to populations becoming unable to interbreed, creating new species. Fossil evidence and genetic studies reveal evolutionary relationships between species and document changes over time.Shutdown123