Evolution (non religious) (1 Viewer)

Mike375 · Sep 29, 2010

I was watching some small lizards on a stone wall a couple of days ago. Lizards and also crocodile/alligator/caimans have legs that come out from the side of the body. If they raise themselves off the ground then their situation is similar to being half way through a push up, that is, your weight is being supported by muscles. The more "advanced" via evolution is where the limbs are directly under the body as is the case for mammals.

However, if those lizards on the wall could suddenly "evolve" so as to have limbs directly under the body then:

1) They would fall off the wall.
2) Even if they could stay on the wall they could not run along the wall.
3) They could no longer slip under small cracks so as to ambush their prey or escape their predators.

Soooo....does evolution really mean a species becomes superior or are we only assessing being superior as meaning more "like us". Using the lizards as an example, they have evolved to perfection to suit their environment so are they any "less evolved" than a dog?

MarkK · Sep 29, 2010

The way I understand it, it's 'natural selection' that does the heavy lifting, not evolution.
In natural selection the most successful adaptation produces the greatest chance of survival and propagation. If a lizard evolves such that it can't escape predation then it gets eaten and dies off. But if a lizard evolves such that it can exploit a niche food supply or escape predation better than his mates, then he lives longer, has more baby lizards, and nature can be said to have 'selected' his new improved traits.
And in respect to degree of evolution, I think the more evolved creature might be said to have descended from the less evolved one. At the same time a more evolved creature might still be poorly adapted and go extinct before his ancestors.
Man, for instance, would be more highly evolved than bacteria, but man will go extinct first.

Mike375 · Sep 29, 2010

lagbolt said:
And in respect to degree of evolution, I think the more evolved creature might be said to have descended from the less evolved one.

I am thinking the same except there are different branches to the tree. In other words the mammal with legs directly under the body did not evolve from the lizard but rather it evolved from an animal or animals with a crappy version of the legs under the body and the lizard has evolved from an animal that had a crappt version of the legs projecting from the side.

My understanding of natural selection is it does not change the species but makes different versions more prevalent. So for some reason the foliage grows a bit higher and thus the impala with longer necks become the prevalent version.

Lightwave · Sep 29, 2010

Mike375 said:
My understanding of natural selection is it does not change the species but makes different versions more prevalent. So for some reason the foliage grows a bit higher and thus the impala with longer necks become the prevalent version.

My understanding is that it can change the species. One becomes the other although in certain circumstances the former species remains.

Individual generations are not separate from their parents however distant direct descendants are sufficiently physically different that they might not be subsequently able to inhabit the same space.

Taken to the extreme a form of cow literally gave birth to early dolphins.

Without the cow there could be no dolphins so the cow has changed or evolved into a dolphin. It is our nomenclature that identifies them as separate but there underlying DNA identifies them as 99% the same.

Mike375 · Sep 29, 2010

Lightwave said:
My understanding is that it can change the species. One becomes the other although in certain circumstances the former species remains.

Lightwave said:

At what point can it no longer reproduce with the former.

If the foliage getting taller means the impala with longer necks become the prevalent versions and then the foliage gets a little taller again until the impala with the longer necks are the only versions of the species then:

1) If someone had kept a couple of the "average neck length" impala in captivity and bred them so they still had some in a few hundred years then one of these captive bred average neck length impalaa could reproduce with a long neck version in the wild?...I think so.

2) If the foliage continues to get taller will the impala become giraffes or become extinct?

Taken to the extreme a form of cow literally gave birth to early dolphins.[/b]

I don't think you can trace the dolphin back to the cow. I think they are different branches of "life's" version of the Big Bang. Altough with life there were and continue to be "Big Bangs"

Or are mutations that occur at the right time and in the right place the method to get from lizard (archosaur) to giraffe?

Rabbie · Sep 29, 2010

Mike375 said:
At what point can it no longer reproduce with the former.

There is no exact point when species can't interbreed. for example horses can breed with donkeys and lions can breed with tigers - the offspring in these cases are infertile. There are examples of bird species cross-breeding and producing fertile offspring.

Mike375 said:
If the foliage getting taller means the impala with longer necks become the prevalent versions and then the foliage gets a little taller again until the impala with the longer necks are the only versions of the species then:

1) If someone had kept a couple of the "average neck length" impala in captivity and bred them so they still had some in a few hundred years then one of these captive bred average neck length impalaa could reproduce with a long neck version in the wild?...I think so.

probably. a few hundred years is very short on the evolutionary timescale.

Mike375 said:
2) If the foliage continues to get taller will the impala become giraffes or become extinct?

If the change in foliage height is gradual enough then there is a chance that the impala will develop longer necks and so survive. It is also possible they will evolve a different strategy for getting the foliage or they may go extinct.

Mike375 said:
Taken to the extreme a form of cow literally gave birth to early dolphins.[/b]

Click to expand...

I don't think you can trace the dolphin back to the cow. I think they are different branches of "life's" version of the Big Bang. Altough with life there were and continue to be "Big Bangs"

There may have been catastrophic events (meteor strikes/ volcanic eruptions on a massive scale) which triggered these

Mike375 said:
Or are mutations that occur at the right time and in the right place the method to get from lizard (archosaur) to giraffe?

All evolutionary changes are due to mutations. Only those changes which do not disadvantage the animal survive. An advantageous change will tend to be propogated through the gene pool

Mike375 · Sep 30, 2010

Rabbie said:
All evolutionary changes are due to mutations. Only those changes which do not disadvantage the animal survive. An advantageous change will tend to be propogated through the gene pool

And natural selection only allows for it to be propogated.

Lightwave · Sep 30, 2010

Mike375 said:
And natural selection only allows for it to be propogated.

Or it becomes extinct

Demetious · Oct 5, 2010

For those of you in KY or traveling through around Petersburg, the Creation Museum delivers an amazing view on evolution/natural selection. Not to mislead anyone, it is Bible based but it is centered around animals, dinosaurs specifically, and it is really a great show to go and see even if you ignore the religious side of it.

MarkK · Oct 5, 2010

KY? Is that that kind of jelly?

Demetious · Oct 5, 2010

lagbolt said:
KY? Is that that kind of jelly?

ky is the Internet country code top-level domain (ccTLD) for the Cayman Islands. Registration is limited to residents and registered companies in the Cayman Islands, and a local address and phone number is required for the registrant and administrative contact.

I however was referring to the state of Kentucky.

Simon_MT · Oct 5, 2010

For those that are curious:

http://www.bbc.co.uk/iplayer/episode/b00m6nhq/The_Cell_The_Chemistry_of_Life/

We are all the same, we share a common ancestor and yes genes can be swapped between species. I'm not advocating you try!

Simon

Evolution (non religious) (1 Viewer)

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