Bob Talks to Kids about Evolution
- Thread starter DavisBJ
- Start date
Read the one I mentioned in the same post from nature.
And here's a better one from Technology Review: http://www.technologyreview.com/biomedicine/22061/?a=f
Alate_One
Well-known member
The problem with epigenetics is it isn't stable so, said "evolution" can never occur permanently. Epigenetics is on TOP of regular genetics, that's why it's "Epi". For speciation to occur, changes need to be permanent, i.e. actual sequence changes.
Again, magazines love to put out controversial covers which aren't really reflective of the science. See Bob's assertions about New Scientist.
I saw photos of some marked single celled organism, and then the subsequent offspring was also marked. These marks did not continue indefinitely, but the scientists, at the the time, needed more data to explain how the mark was carried into offspring when it was superficial and not part of the information passed by the DNA. Epigenetics is pretty interesting.
Utter poppycock! Evolutionists will point at literally anything to justify the idea of speciation. Why there was a bird that was singing differently and that was said to be the start of it! "Species" is an utterly vacuous term and so vaguely defined as to be next to useless.
This is totally arbitrary but i would define a species as a group of animals that share at least 98% of the exact same sequences, including non protein coding sequences, Have the exact same number of chromosomes and 95% of all sequences are found on the exact same chromosome . IOW, any one chromosome must be identical in all animals of the species 95% of the time. It can't be 1,2,3,4,5 on chromsome 6 for animal A , and 5,1,4,2,3 on chromosome 6 for animal B.
Alate_One
Well-known member
This is from someone that uses the completely useless definition of "kind". Species can be defined fairly well by interbreeding in animals.
Alate_One
Well-known member
With the advent of better and cheaper sequencing technology that is probably similar to what will eventually be used.
Many organisms are distinguished based on DNA barcoding currently.
:squint: What on earth are you talking about? "Kind" is an easy to understand, complete and utterly definitive description based on common ancestry. If two animals share a common ancestor, they are the same kind. Every time we have this conversation we are both easily able to understand what each is talking about. You find it useless because you think there is only one kind and you ignore the fact that sub-groups can easily be defined even if your assumption is true.
No, it can't. There are so many little caveats hidden in this description to make your description next to useless. Species generally comes down to a scientist declaring it so and a whole lot of people just accepting it (unless they argue with it).
Alate_One
Well-known member
Hey Stripe, how do you KNOW what shares a common ancestor and what doesn't?
I've been over this with you. You have real problems being able to tell me when two creatures are the same "kind" or not. It's absolutely arbitrary and based on what Stripe thinks can't have evolved. It's the most moronic "system" possible.
In many cases species are pretty obvious. Horse and donkey, different species. Lion and Tiger, different species.
I don’t know what Disney production you are referring to, but since it was presented as “a children’s cartoon”, that establishes that it was to be taken as fictional entertainment.
You really want Disney to toe the line, never openly venturing into fantasy? For public school teachers ignorance of correct evolutionary ideas is a valid (poor, but valid) excuse. In contrast, Enyart was not ignorant, just dishonest.
I looked it up. What in that is Lamarkian to you?
I’m sure you know Enyart better than I. You think he is so incompetent that in 30 minutes he can’t portray evolution with fidelity.
Ouch! but accurate.
AlateOne. Donkeys and horses are different species but they are the same biblical kind. Did both appear in the fossil record at roughly the same time? Are the sequences in the genome nearly identical? What really narrows it down is whether donkeys and horses are closer genomically to each other than they are to other animals? If they pass all of the above, the final question of whether they are the same kind is if they have an identical number of chromosomes and if each chromosome is roughly the same length in each animal. There are a number of criteria that must be met in order to be of the same kind in my book.
Alate_One
Well-known member
When you're talking about many modern species, there won't be a fossil record that is identical to them. There are actually several species of wild donkey.
They have a different number of chromosomes. 62 in the Donkey vs. 64 in the horse. As do the different species of zebra having anywhere between 32 and 46.
Chromosome numbers can be vastly different between two organisms that otherwise look identical, for example the raccoon dog has two forms (a mainland and an island form), one of which has a chromosome number of 38, the other 54.
Either way if you choose to accept evolution from ancestral biblical kinds you'll have to accept the fact that chromosome numbers can change substantially. Here's a paper describing changes in the horse lineage And if you accept that level of genetic change, there is absolutely no reason to not accept the level of genetic change between a human and a chimpanzee (since it is far less). They too must have shared a common ancestor.
You want all of those to be the SAME for something to be the same kind?
An example. I would say that whales and hippos are the same kind. They are closer to each other genomically than they are to other animals. The whale can be traced back to the basilosaurus of the oligocene. The hippo can be traced back to the anthrocotherium magnus also of the oligocene. Thus both have unambiguous fossil ancestors appearing at the same time. Both of these ancient animals are even toed ungulates. Others of this group include the pig and the camel and the cow. Both whales and hippos are far removed genomically from these animals however, and so the logical conclusion is that whales and hippos evolved from an extinct member of the even toed ungulates that never flourished enough to make it into the fossil record.
Nice straw man. We do not need to be able to classify every organism in order for the classification system to be simple, descriptive and useful.
And yet...
...Mbuti and Inupiat - same species. Go figure. :idunno:
Your distinctions are more politically motivated than anything. Most of all, the ridiculous numbers you can come up with for the number of species on Earth helps you disguise and protect your evolutionary theory.
Alate_One
Well-known member
What straw man? I simply asked how you know what shares a common ancestor, the very definition you're using for "kind". It's amazing that you think asking how you use your definition in practice is a "straw man". :kookoo: And then what exactly is your problem with species, since most species are obvious?
You really are a moron.
Politically motivated? Name me a species that is "politically motivated". Do you think "kind" isn't motivated by a desire to force the world to conform to YEC theology? You are the definition of irony.
AlatOne. You mentioned the differences between horses and zebras and donkeys in numbers of chromosomes. Im not sure about my chromosome restriction yet in regards to what is a kind yet. You gave a link how the evolution of horses. I only saw it talking about centromere moving on a chromsome. Are you saying the number of chromosomes has changed quite a bit as the horse has evolved? Im not sure i buy that. The genomes of the chimp and man are indeed very close but but that is only one qualification that i gave. Where is the fossil record for chimp evolution? where does it start? Where is the fossil record for human evolution, as you see it ? Where does it start? Is there a good reason for claiming that particular list of fossils as a human lineage? Where does it start and does it start at the same time as the chimp lineage? It has to be that way for both to be considered part of the same kind.
The morphological similarities between chimps and humans are also far outweighed by their morphological differences. Plus, the morphological similarities are also shared between other species as well and therfore cannot be considered to be unique to the chimp human relationship. You said that if I could allow such great evolution in the lineage of horses, why not allow it in the evolution of ape to man. This is assuming that changing the chromosome structure is a huge evolutionary change. It seems obvious that zebras and horses are of the same kind. Yes, there is a great variety in the number of chromosomes. I think i was in error on that restriction and agree that such evolution of chromosome number would also be possible in an ape to man evolution if that indeed did happen.
Instead of equal number of chrosomes being a restriction on what a kind is, i think genome size would be better. That includes the non protein coding DNA as well. I also think a large percentage of each chromosome should be identical for there to be a kind. Chromosome 6 in both human and chimp should be more similar to each other than any other pair of animals and that same guideline should be applied to the other chromosomes as well. So while chimps and humans may have different numbers of chromosomes and that difference in itself is not restrictive, the number of chrosomosomes that they do have in common shoul be very nearly identical and i don't know if that has been established.