why do we not see evolution in humans?

[Dragar]

Guys, think about what the word 'species' means in science.

Species X is a seperate species to Species Y when members of X cannot produce fertile offspring with members of Y.

In other words, we shouldn't be surprised that different species cannot produce fertile offspring with each other, because that's the criteria we use to determine what members are of the same species and what are not!

Dragar

 

[Ishmael Borg]

Guys, think about what the word 'species' means in science.

Species X is a seperate species to Species Y when members of X cannot produce fertile offspring with members of Y.

In other words, we shouldn't be surprised that different species cannot produce fertile offspring with each other, because that's the criteria we use to determine what members are of the same species and what are not!

Dragar

Well, ANYONE can see it easily that way! But go ahead, throw all my hard-googling away (if we don't use this bandwith, who will?).

 

[Dragar]

The argument that apes and humans cannot produce fertile offspring because they are different species suddenly looks a bit circular, doesn't it?

A better argument would be that the differences in the genetic code are too great. And I think this is probably correct. But...it is be no means certain.

If it wasn't for those silly 'ethics' and 'morals', we'd be able to find out. As it is, we'll likely never know....

Dragar

 

[Nathan Poe]

If it wasn't for those silly 'ethics' and 'morals', we'd be able to find out. As it is, we'll likely never know....

Dragar

Also the fact that nobody's that desperate for a date...

 

[Dragar]

Also the fact that nobody's that desperate for a date...

You don't hang around physics students much, do you?

Dragar

Disclaimer: That was a joke. I'm a physics student myself. Laugh.

 

[Nathan Poe]

You don't hang around physics students much, do you?

Dragar

Disclaimer: That was a joke. I'm a physics student myself. Laugh.

Perhaps the apes think they can do better?

 

[Mistermystery]

That's cool. We like evidence here (as if you hadn't noticed, ha ha). I like the fact that you seem to be honest in asking questions.

Yeah I mean honestly, if only everyone just came here to learn instead of just tell us that we're wrong "because of the 2nd law of termodinamiks". You're cool in my book too brightlights.

 

[billwald]

We don't observe evolution occurring in humans because sentience short circuits the process. Evolution is a random process of natural selection. Humans choose mates intentionally and preserve life that naturally should die. For example, modern meds permit people with genetic defects to propagate the defect.

 

[Hydra009]

We don't observe evolution occurring in humans because sentience short circuits the process. Evolution is a random process of natural selection. Humans choose mates intentionally and preserve life that naturally should die. For example, modern meds permit people with genetic defects to propagate the defect.

You're right that obviously, some - but not all - people with health problems (inherited or not inherited) are treated and survive in modern times when they obviously wouldn't survive in previous ages. This somewhat lessens evolutionary pressure, but it doesn't eliminate it.

However, there are other mechanisms of evolution than survival of the fittest. You even brought one of them up in your post - "Humans choose mate intentionally". That is known as sexual selection.

 

[Terral]

if you look back at our earliest depictions of humans on pottery, walls, etc... why do they still resemble the humans of today? if evolution is continuous why have we not seen it these last 6000 years? this may be a stupid question, but i thought of it while driving today and thought it wouldnt hurt to ask.

If evolution is living organisms adapting to the environment, then we can see human evolution in our species in as little as the past 200 years. People are much taller now than in centuries past. The four minute mile barrier existed for thousands of years, but now people do it all the time. Do we see any Neanderthal men running around today? No. Why not? Because, they failed to evolve to the changing environment. The Homo Sapiens species exists as a testament to our ability to evolve, according to the geological record.

Terral

 

[brightlights]

points.

height can be attributed to evolution of nutrition.


if you look at graphs of olympic records (4 minute mile etc...) it is VERY apparent that an asymptote exists. there is a limit in which x is moving towards but will never touch.

 

[ForeRunner]

points.

height can be attributed to evolution of nutrition.

Didn't we cover this already.

 

[brightlights]

yes but someone brought it up again

 

[Wayfarer]

if you look back at our earliest depictions of humans on pottery, walls, etc... why do they still resemble the humans of today? if evolution is continuous why have we not seen it these last 6000 years? this may be a stupid question, but i thought of it while driving today and thought it wouldnt hurt to ask.

Explain to me why human's have organs such as an appendix if they are completely useless? Why do humans have tailbones?

And we are changing slowly. Each generation has less body hair, larger feet, etc.

 

[Nathan David]

try to pregnate a female ape with human sperm

Existing animal species cannot (generally) interbreed. But that's not what I was asking. What "barrier" would prevent a population of one species from evolving into a different species?

 

[Mainframes]

Explain to me why human's have organs such as an appendix if they are completely useless? Why do humans have tailbones?

And we are changing slowly. Each generation has less body hair, larger feet, etc.

Excuse me if I jump in and answer instead...

The appendix is subtle proof of evolution. A distant ancestor of ours may have found the appendix a useful organ but over time the eating habits of our ancestors changed and the appendix was no longer a vital organ. After this it no longer mattered when people were born with defective appendices and thus the genetic coding for a poor non-functional appendix began to spread throughout human kind. This has eventually lead to the situation today where a typical human has a non-functional appendix, which given further time may well disappear altogether.

Exactly the same is true of tailbones ie they are remnant of our ancestors tails which at some point were not of vital importance and thus has had a similar decline.

 

[Wayfarer]

but come on, I want to see something that brings us from a single cell organism to what we are today.

Is it really so hard to imagine, when you yourself start from a single cell? (sperm, the embryo, then a zygot)