How did we come to be?

[Fellowes]

I do not know much about this subject, which of course brings me to wonder: how did we as humans come to be? How did dinosaurs come to be? What started life on earth? Was there any species before dinosaurs? How does evolution work? I know this is a lot to answer at once but these have been buggin' me. Anyone know, or have any theorys?

[-Demosthenes-]

There's always the good old theory of evolution.

[coquina]

Life started with very simple organisms. It continued because they were able to reproduce. On the cellular level, there are things called "chromosomes" and within them there are "genes".

 

Over a period of time, when the cell reproduces or replicates, the offspring are not exact copies due to chance changes in the genes which are called "mutations". Mutations can be beneficial - they make it easier for the organism to survive in its environment; detrimental - they cause the organism to die before it has the chance to reproduce, or neutral - they are different, but don't make a difference at the time (but they might be beneficial or detrimental at sometime in the future.)

 

Let's take the over used example of the giraffe and it's long neck. Giraffes did not acquire long necks because their parents' necks became longer from stretching to get to food on top branches.

 

There were chance mutations in the "neck gene" - some giraffes were born with short necks - there was not enough food within their reach, so their "detrimental gene" caused them to die before they were able to reproduce.

 

Some giraffes were born with necks of the same length as their parents - they did fine for awhile.

 

Some giraffes were born with necks that were longer than usual. That allowed them to reach an area of the canopy where they didn't have to compete with any other animal for food (they occupied a new "niche") so more of them survived to reproduce.

 

Over time, the giraffes with the long necks had more offspring than the giraffes with the shorter necks. As those offspring mated with one another, the ones that survived and reproduced most often were the ones with the longest necks.

 

How did we, the dinosaurs, and all the other creatures that have lived on earth come to be? We, the dinosaurs, and all the other creatures that have lived on earth, were able to occupy a niche. A niche consists of everypart of an animal's habitat. What is eats, what eats it, the temperature in which it can survive, whether it lives on land, in fresh water or salt water, and a host of other environmental factors. Through evolution, organisms adapt to fit niches.

 

People study this stuff for years, and it is fascinating. I sure can't explain it all to you (and I don't know it all by a long shot) in a couple of paragraphs. I hope I have intrigued you enough that you want to find out more.

[Ophiolite]

How does evolution work? I know this is a lot to answer at once but these have been buggin' me. Anyone know, or have any theorys?

The November issue of National Geographic has an excellent article on Evolution. I would thoroughly recommend it.

[Spaceman]

I do not know much about this subject, which of course brings me to wonder: how did we as humans come to be? How did dinosaurs come to be? What started life on earth? Was there any species before dinosaurs? How does evolution work? I know this is a lot to answer at once but these have been buggin' me. Anyone know, or have any theorys?

The most important thing is not to get bogged down.Read as many books about evolution as possible,some are excellent but never confuse evolutionary theory with evolution.The latter is fact the former speculation.Also dont see evolution as improvement ,they are loads here who think that,but evolution only does the best it can with whatever material it has at hand,it doesnt make something superior.

 

as for how life came to be....guess i wont disagree

[Sayonara]

Also dont see evolution as improvement ,they are loads here who think that,but evolution only does the best it can with whatever material it has at hand,it doesnt make something superior.

That's the most sensible thing I've seen you post.

 

Hurrah.

[Fellowes]

I see, anything else?

[c dawg]

if ya really wanna know wait till world history next year. or if you want to know now i can hook you up with one. it discusses all about the corw magnons and all the advances in technology between homo habilus, erectus and sapeins. it also tells about many other species where they were belived to have originated from and when they died out or eventually replaced.