why is sexual reproduction necessary?

Question

if asexual reproduction quickly produces large numbers of offspring, why is sexual reproduction necessary?

Answer 1

but humans arent asexual.

Answer 2

For genetic variation. That's needed not exactly for evolving, but to generate offspring with better survival possibilities. And that's needed because sexual beings have parasites (viruses, bacteria,etc). Therefore, having the ability to interchange genetic markers, inmmune systems, etc makes the offspring less vulnerable to the parasites of their parents (a problem that nonsexual beings, like the domestic industrial varieties of wheat, maize and other cereals have, to the dismay of the farmers that prefer asexual crops to prevent variation of quality). However sexual reproduction is not the only method to do this, sex is just needed (certain bacteria have sex, interchanging DNA during the intercourse to mutate themselves). Also sex is not a constant in sexed species (certain waterflies are asexual during generations and, when their pond is drying, they generate males to have sex so that the new eggs, once the pond regrows, will have varied members). Finally, there's no evolutionary reason for having JUST two sexes, and specially separated sexes (and not hermaphrodites) that has been discovered, although there are some theories. The first one says that we have two sexes because of the effort one spends in getting a couple, which will be double with a third sex, triple with a fourth, etc. And the theory of what we have differentiated sexes comes from carriage (of babies or eggs), that debilitates the offspring carrier. Also, there are some benefits due to being each sex that some evolutionary models explain.

Answer 3

Sexual reproduction increases variability. Asexual reproduction occurs through mitosis, with all chromosomes of the parent cell passing to the daughter cell.

Most sexual reproduction occurs through meiosis. Each parent contributes only half of their genetic material, using one chromosome from either their father or mother for each of the chromosome pairs. However, these chromosomes can cross over and create recombinant DNA. When you combine two sex cells (which there are many of, all different from each other), you get variation from both parents in multiple ways. No two organisms are likely to be alike.

Interestingly, there is a recent trend towards asexual reproduction, evolutionarily speaking. It seems that indeed asexual reproduction is more effective in times of evolutionary equilibrium, when less change is required. So sex isn't really "necessary," it is simply more useful in creating diversity.

Answer 4

Good question. I'd like to know the answer.

I can tell you this much that heterosxual sex is only for reproduction, but sex in general isn't primarily for reproduction, since all female species too have sex ----- with other females.

Don't forget that life started as being unisex. Sexual Dimorphism occurred later on.

So the primary and original purpose of sex doesn't seem to be reproduction but social bonding.

Answer 5

1. Are you seriously asking this question?
2. Sexual reproduction allows for changes in genetic structure.
3. How would you feel if every few hours you split in half?

Answer 6

It is necessary because it is part of our nature and culture. Asexual reproduction is only common in some plants and animals. Humans will feel a better connection with their offsprings if it comes from them not from test tubes.

Answer 7

By combining the genetics of two individuals to make the offspring, it allows for genetic diversity and variation. Without variation it is more likely to die out.

Answer 8

Because parents composed of a male and a female mother and father are more likely to generate emotionally healthier people than people raised by a single parent, a foster parent, an orphanage, and yes indeed by same sex parents.

Men and women are different. To be healthy we need role models from BOTH sexes. Women are caregivers. They make the child feel loved and secure. Fathers are supporters and protectors. They make the child feel respected and worthy. BOTH emotions (love and respect) are CRITICAL to emotional health. Children need PARENTS of BOTH sexes to be a fully healthy adult.

Answer 9

Asexual = same genes passed = no variation = stopped evolving = bad

Sexual = different genes passed = variation = evolution adaptability

The survival of a species is depentant on its adaptability to their environment and its surrounding... When you stop evolving your as good as dead, take a look around i can only think of 1 species that is asexual and its a tiny lizard!

Answer 10

And even as do we get our souls? What about the billions of organic (not trauma-led to) miscarriages, or similar twins that cut loose a unmarried fertilized egg... If "He" knew us beforehand we were born, what precisely is "He" attempting to instruct now? Overpopulation, conflict, and starvation?