Why do you think that sexual reproduction is considered a pillar of evolutionary

Why do you think that sexual reproduction is considered a pillar of evolutionary advancement? Practically all species (except the most simple) have the ability to reproduce sexually. What do you think are the evolutionary advantages of sexual as opposed to asexual reproduction?Meiosis is a complicated process. When you consider the process of pairing in prophase and the accuracy needed for two cell divisions, you might not be surprised to find that often things do go wrong. In humans, for example, about one third of all pregnancies spontaneously abort in the first two or three months. Most of these aborted embryos have the wrong number of chromosomes. Failure of the chromosomes to separate correctly is called nondisjunction.Not all failures of meiosis result in early miscarriage. There are late miscarriages and stillbirths of severely malformed fetuses with wrong chromosome numbers. In addition, about one live-born human baby in 200 has the wrong number of chromosomes, often accompanied by severe abnormalities.One of the most common chromosomal abnormalities is Trisomy 21, or Down’s Syndrome resulting from three copies of chromosome 21. This occurs in about one baby in 600. Characteristics of Down syndrome include rounded features, an enlarged tongue that often protrudes, and various internal disorders. Trisomy 21 occurs more frequently among babies born to women over 35 years old. The age of the father has little or no effect.What do you think are possible reasons leading to this meiotic nondisjunction in female eggs? It is interesting to note that the total amount of women’s eggs are already set by the time she is born, while a man’s sperm is continuosly produced. Do you think that there could be some other environmental problems affecting this situation?