Complex sentence: In the early 20th century, Darwinian theory by means of natural selection revealing the facts of evolution was advanced by Gregor Mendel's laws of genetic inheritance, which culminated into an extensive quantitative synthesis of evolutionary inheritance known as the modern evolutionary synthesis.
Split into simpler sentences: In the early 20th century, Darwinian theory by means of natural selection revealing the facts of evolution was advanced by Gregor Mendel's laws of genetic inheritance. This culminated into an extensive quantitative synthesis of evolutionary inheritance known as the modern evolutionary synthesis.