How did gender evolve?

Question

I am looking for a suitable explanation on how it is possible, by process of evolution, to get male and female.

Answer 1

Matt Ridley's book "The Red Queen" gives a fairly good summary of current thinking.

The obvious advantage of sex that is usually cited is the mixing genes to produce new combinations. However it is hard to show that this makes up for the fact that in sexual reproduction you only pass on half your genes, while in asexual you pass them all on. If evolution has favored sexual reproduction then it must somehow be twice as 'good' as asexual in the long run.

Answer 2

Echanging genes is a very good way to get new genes and correct mistakes in faulty genes.
So how would an organism exchange genes?
We already know that some bacteria can exchange genes.
So they probably kept this ability when they worked together as multi-cellular organisms.
The best time to exchange genes is when you form a new organism (offspring) from one single cell; you can't replace the DNA of a fully grown organism without killing it.
But you can for a single cell from two organisms, and then grow it to become a new organism.

So, long story short: It's a good idea (demonstrated by the fact that 99.99% of all organisms on this planet use it).
It has a basis in gene-exchange in single-cell organisms.
When you develop multi-cellular organisms, you get some differentiation, as one is going to actually grow the baby, and the other only needs to supply his genes.

Answer 3

Look back farther into evolution.

Bacteria regularly exchange genes. In effect, eat each other. Mitochondria DNA, passed through the female from mother to daughter only, is thought to have an independent bacterial ancestral life that lives on in our every cell.

This mitochondria DNA is the energy source of each of our cells. It is probably the origin of sex in that when it is in the female egg in utero and a sperm comes along and attaches to the egg, this particular DNA grabs the genes from the sperm and produces a new sexually originated organism.

Answer 4

As apposed to asexual animals? It probable evolved to create stronger beings. Asexual reproduction is a large gamble in most cases like coral or ferns. Traits not suitable for that environment may be dominant. Where sexual reproduction would weed out weaker traits. I think it is more of the stronger survive tactic.

Answer 5

That is one helluva good question. If life gradually evolved into single cellular organisms, at first it must have undergone asexual reproduction. But at what point did sexual reproduction become necessary? When the complexity of evolution exceeded that attainable by asexual reproduction, so as to require the genetic diversity of two separate sets of DNA? I'm just cogitating now; it's the kind of question that will keep me up nights. Darn you!!

Answer 6

asexual reproduction produces offsprings with hardly any varietions as most are exact copies of the parent cell. however an increased no. of variations increases the probability of the survivial of the species in case of environmental upheavals, in terms of adaptation and the survival of the fittest and sexual reproduction increases the chances of bringing variations in the gene pool by innumerous recombinations. therefore as increased incidence of variations was favoured in evolution male and female genders were developed again by specific mutations, first as mild variations that were favoured which later became more and more pronounced.

Answer 7

Compex species have an exchange of genes at cell division
Organisms that are simple dont and only have one gender as they are hemprodites