Evolution..............

Question

So in the beginning of time when there was like one creature on Earth (an Amoeba or whatever) when did this creature evolve to become male or female? Why?

Answer 1

most of the unicellular creatures don't have male female, they divide. Then came the creatures that had male female in their own bodies and self fused. Then separated. Nobody can give a correct proof of when it happened, all scientist will say any where from few million to a zillion years (pick a number) before (as if their great great great...... grandfathers were witnessing it).

The truth is that nobody knows, even you can come up with a theory and say that is what happened and a whole bunch of people will back you up and another whole bunch will try to keep you shut :)

Answer 2

Time began billions of years before the Earth formed, and then hundreds of millions of years lapsed before the first life, far more primitive than an amoeba, arose.

Sexual reproduction is a means for a population to share genetic information.  There are organisms that can reproduce by forming gametes that can fuse with gametes from the same organism.  Some have developed "mating type" systems that require the gamete have another mating type (and there can be more than two) in order to fuse.  That prevents autofertilization.  Male and female are an extension of this, where one gamete tends to be sessile or vegetative (female) and the other is mobile (male).  This arose with multicellularity.

Answer 3

A single celled creature, dividing by standard cell division (mitosis) has all the same genetic material as the parent cell. However, if you divide the genes in the cell in half (meiosis) it becomes either a male or female gamete. To become a viable cell it has to merge it with a half of the opposite s*x from a different individual. In this way you get a mixture of genetic material, which results in greater genetic diversity and may confer a greater ability to survive.

In some circumstances, e.g. with large, mobile organisms, there are clearly advantages to this, and according to true evolutionary principles, sexually reproducing organisms will be favoured in the fight for survival.

That is not to say that organisms which reproduce asexually, such as some plants and microorganisms are not sucessful, they just occupy a different niche to large mammals. As for when this remarkable adaptation happened, probably sometime within the last three billion years.

Just to throw another log onto the fire, it is now felt that the amoeba, with all of its separate organelles within its single cell may well have evolved from a multi-celled organism whose internal cell walls have broken down, and so looks like a single cell! The oldest and most primitive single celled creaures were more likely to be like a bacteria or yeast than amoeba.  

Answer 4

We think sexual reproduction began about 1000 million years ago. Sexual reproduction allows for greater genetic variation, which supports evolution by supporting the ability of a population to adjust to environmental pressures, thereby enhancing a species' ability to survive long-term.

Answer 5

Sexual reproduction appeared as a way of exchanging genetic material. That way the new individual are differt from the parents and may give it an advantage to survive in adverse conditions. And it gives more probabilities to mutate wich is the base of evolution wich is just the way that differt beings are adapted to their enviroment. Otherwise all the beings in the world would be clones. Of course the beings that don't have sexual reproduction also mutate. But imagine thet we were all clones and we were all white with blue eyes and blond. Now imagine that the world changed and we had a much bigger solar radiation. We would all die from cancer and sunburns. But if that happend in our world, black people would most likely survive, so our specie would still exist.

Answer 6

Wow ... another creationist working at denying the evidence for evolution.

I always find it interesting that creationists reject the evidence that life can only come from life and that humans evolved from lower life forms such as apes.  Yet at the same time, those same creations have no problem simply believing a book written 1800 years ago by scientific illiterates that states that humans came from dirt.  

Answer 7

There is a major error in the statement of the question.  The current estimates for the age of the universe are in the range of 12 to 14 billion years ago.  The best data shows that the earth formed about 4.5 billion years ago, and the oldest evidence for life on earth is about 3.8 billion years ago.  Thus, there was not even an earth, much less a life form, when time began.

Answer 8

i think your answer is here.

http://theoutlineofscience.com/the-outli...

it's quite long, but what i've read is well written.

the question now is,  are you interested?  or are you just trying to deny evolution?

i'm betting on the latter.

if i had to guess, you'll like this one better.

http://www.creationscience.com/onlineboo...

"This remarkable string of “accidents” (ie sexual reproduction) must have been repeated for millions of species."

well, or maybe just once, and that was passed on to all subsequent species.  but, of course, that idea is dumb, and undermines the argument.

Answer 9

Not on the original question, but on the responses:  Wow, three "top contributers" who can't read, or who are paranoid about creationist trolls.  Or at least can't read accurately beneath the question.  This is a question from someone who is a product of the US educational system.  He(?) has a faint idea of what to ask - he did say amoeba "or whatever".  And at its core a great question; why did sexes arise? was a major question in evolutionary thought for decades.  //  So you did get a few very good answers.  Keep asking the questions and reading - it's the most fascinating subject.  Check out essays by Stephen Jay Gould (there are a lot of them but they're like popcorn).

Answer 10

When s*x first evolved there wasn't what we consider male and female.  Sexual reproduction is just the creation of a new combination of genetic material by the fusion of different sets of DNA.

In some organisms today, including fungi and many algae, there are no male and female.  There are + and - strains.  The reason they're not considered male and female is that the definition of a male is the s*x that produces small, motile gametes while the definition of the female is the s*x that produces large, immotile gametes.  In fungi and many algae, gametes are isogamous (same size and shape).  

s*x evolved because creating new genetic combinations allowed species to adapt to changing conditions, including abiotic things like temperature, moisture, etc., and biotic pressures like competition and prey type.  

The reason the different sexes evolved is that there are essentially two different strategies within the species.  One strategy is to produce lots and lots of gametes and hope that a couple manage to make it into the next generation (i.e., sperm).  The other strategy is invest a lot of resources into few gametes (i.e., eggs).  

So, if you're going to make tons of gametes and hope for the best, it's helpful if they have the ability to move themselves to the egg.  If you're only going to make a few gametes, then you better make them big so the sperm can find them and so they can hold as much nutrition as they can, giving those offspring the best possible chance.

Answer 11

I will assume that you are a serious questioner, not just another creationist troll.

Nothing like an amoeba. Amoeba is an example of a eukaryote (so it is more closely related to you and me than to bacteria), formed by a massive pooling of genetic material between bacteria and archaea (look them up).

The evolution of s*x presumably only happened after the development of multicellular organisms.  The value of s*x, rather than just reproducing by budding, is to shuffle genetic material and maintain genetic variation. s*x looks as if it is very wasteful biologically, since it is the ability specifically of the females to have offspring that limits the rate of reproduction, but this is more than made up for by increased adaptability, the greater rate of spreading of favourable variations through a population, and the fact that a genetically varied population presents more of a challenge to viruses and bacteria.