problems with macroevolution

[sandwiches]

The point is to falsify evolution. Others go out to try to square the circle, or invent perpetual motion machines.

A person who wanted to understand it would spend some time reading and thinking.

I noticed you used the phrase "squaring the circle" within a couple of minutes of each other in this thread and in the "Humans are neither unique nor special" thread. What does it mean?

 

[laconicstudent]

I suppose. I find it amusing when people try and claim that skeletal morphology is very little information. The degree to which we can classify animals based on simply bone structure is amazing. Do you know we can determine whether a speciman was bipedal simply by the location of their foramen magnum? (hole through which the spinal cord passes in the skull)

 

[Hespera]

I noticed you used the phrase "squaring the circle" within a couple of minutes of each other in this thread and in the "Humans are neither unique nor special" thread. What does it mean?

Inventing a perpetual motion machine or squaring the circles are exercises in futility. Squaring the Circle from Interactive Mathematics Miscellany and Puzzles

Theocreologists trying to falsify evolution is another one, tho in theory it is possible while the other two are just plain impossible.

 

[dawiyd]

RTooty, before I reply, could you please tell me what your knowledge is of the mechanisms that underpin both micro and macro evolution, and how they differ?

Thanks

 

[Steve Petersen]

How can we be certain that the differences between our fossilized ancestors and us isn't just variation within a species?

How exactly do we determine that Neanderthal was a different species from modern humans if the only method of testing them is forensic differences in their skelatal remains?

 

[Hespera]

How can we be certain that the differences between our fossilized ancestors and us isn't just variation within a species?

How exactly do we determine that Neanderthal was a different species from modern humans if the only method of testing them is forensic differences in their skelatal remains?

Some pretty good dna has been recovered from Neanderthal. its not the same as modern man.

Skeletal remains tell a great deal.

A monkey, a dog, a bear etc, all have the same basic skeleton.
The pattern is solidly established back in the amphibians. But we can tell them apart! This is a black bear skull. This is from a grizzly. This is the femur from a cat. That is a camel toe bone.

Certainly every bone of a chimp can be matched to its human counterpart, and teh differences are not that great. Longer here, more curved there, wider there. Same bone, a little different shape.

Keep in mind that "species" is a human concept that we use for convenience, but there are no "bright line" distinctions to be found in nature. Why is a cow a different species from a buffalo? They can interbreed and produce fertile offspring.

Neanderthal is very noticeably different from sapiens. Kind of like cow / buffalo.

At some point a person can say well, a dog is not the same as a wolf.
So lets call them different species. A fox is so different that we will give it a seperate genus. A deer is so different from a camel we will give it a different family name. Keep in mind that people have dissected and studied these animals in incredibly painstaking detail. Its not just whimsical naming.

Skeletal remains, side note here, are a sort of negative of the muscles, which can be very accurately reproduced from the skeleton. They also tell a great deal about the nervous system, circulatory system, and digestive system.

There is way more too it that just holding two bones up and noticing they are kinda different.

 

[keith99]

I noticed you used the phrase "squaring the circle" within a couple of minutes of each other in this thread and in the "Humans are neither unique nor special" thread. What does it mean?

Squaring a circle is a problem in constructive geometry that goes back to the Greeks. Rather like bisecting an angle. The idea is to construct a square that has exactly the same area as a circle. I believe it has been shown to be impossible, for many years it had not been done and also had not been proved to be impossible.

 

[Pete Harcoff]

I agree with the OP. No one has yet been able to explain to me how speciation can occur with a change in chromosome number. Apes have 24 pairs of chromosomes but humans have only 23 pairs. Somewhere in time, a fusion must have occured. But such a major change in chromosome structure means that the animal in which it happens can't breed with any of the original species. So how does the chromosome change get passed down?

It's possible. It actually happens in humans. Chromosomes undergo fusions and people still reproduce. In fact, there are isolated cases of parents each possessing a fusion, which results in an offspring with only 22 pairs.

For example, Human chromosome variation with two Robertsonian translocations :

A woman was found to have 42 autosomes due to engagement of both chromosomes 14 in Robertsonian rearrangements, one with a chromosome 21 and the other with a chromosome 22: t(14q21q) and t(14q22q). The two translocations appear monocentric and by silver staining have no rRNA activity. The t(14q21q) translocation is familial and was ascertained through a nephew with Down syndrome, while the origin of the t(14q22q) translocation was not established. In addition to these two translocations, the woman had XX/XXX sex chromosome mosaicism. She has had two recognized pregnancies, each resulting in the birth of a child with one of the two translocations. Both children are phenotypically normal, as is their mother, the first normal liveborn individual identified with two Robertsonian translocations.

 

[Split Rock]

How can we be certain that the differences between our fossilized ancestors and us isn't just variation within a species?

How exactly do we determine that Neanderthal was a different species from modern humans if the only method of testing them is forensic differences in their skelatal remains?

This is a good question, and explains the dithering between calling Neanderthals Homo neanderthalensis and Homo sapiens neanderthalensis. Recently, research on sequencing Neanderthal DNA has provided support for the former.

Basically, when we only have fossil remains, it is something of a judgement call as to whether a hominid fossil represents a new species or just a variant of an known species. In fact, I went to a seminar a few years ago, where a researcher proposed that all Homo species are really variants of one species... ours.

I guess I'm not sure why it matters to you so much. Neanderthals were indeed different from us, regardless of whether we qualify those differences as enough to consititute a different species. Other Homo species were more different, all the way down to Australipithecines. Where we draw species lines is really not all that relevant. Of course, if it is not obvious where such lines are to be drawn, then that is even more evidence for the evolution of man. If all Homo species can be called one species, then we certainly evolved from those earlier hominds.

 

[Agonaces of Susa]

How can we be certain that the differences between our fossilized ancestors and us isn't just variation within a species?

We can't be certain. Almost no difference at all between the various alleged and so-called "species" of the genus Homo.

The only difference is that Homo sapiens are inferior to the alleged precursors because Homo sapiens have devolved.

How exactly do we determine that Neanderthal was a different species from modern humans if the only method of testing them is forensic differences in their skelatal remains?

Well that's not the only means. We also have the cultural remains such as artifacts. Which are also similar.

It seems Homo sapiens and Neanderthals lived alongside one another which falsifies the myth of evolution which says Homo sapiens evolved from Neanderthals. Homo sapiens existed simultaneoulsy, therefore cannot have evolved from Neaderthals.

 

[Pete Harcoff]

It seems Homo sapiens and Neanderthals lived alongside one another which falsifies the myth of evolution which says Homo sapiens evolved from Neanderthals. Homo sapiens existed simultaneoulsy, therefore cannot have evolved from Neaderthals.

Dude, it's been known for a long time that Neanderthals didn't evolve into humans. This isn't exactly a "myth of evolution".

 

[Hespera]

Dude, it's been known for a long time that Neanderthals didn't evolve into humans. This isn't exactly a "myth of evolution".

Isnt there a sign at the zoo with a sign about what not to feed?

 

[Pete Harcoff]

Isnt there a sign at the zoo with a sign about what not to feed?

Bears?

 

[laconicstudent]

Isnt there a sign at the zoo with a sign about what not to feed?

Yeah, at the penguin tank at my zoo, because its sort of an open pit in which it would be really easy to throw food into. So they have signs every 2 feet reminding us not to feed the penguins.

 

[Hespera]

Yeah, at the penguin tank at my zoo, because its sort of an open pit in which it would be really easy to throw food into. So they have signs every 2 feet reminding us not to feed the penguins.

i was thinking mostly of not feeding the sort of things that live under bridges like in the 3 billygoats story.