Results 41 to 50 of 61
-
February 27th, 2016 04:07 AM #41
While evidence of evolution from the first life form (LUCA) has been abundant, the big leap from primordial soup to life (abiogenesis) is still a widely debated branch of science.
Many theories are present, but no consensus has been arrived at when it comes to a standard model on how life came to be. At the very least, most theories subscribe to the idea that molecules were synthesized under natural conditions to become the basic biological building block, the cell.
Just because the progress pre-LUCA isn't as conclusive as post-LUCA doesn't make the developments of the latter any less valid.
To answer your questions, I would only go as far as saying that the presence of energy (geothermal, solar, etc) acted on non-living molecules in a favorable manner that allowed the first life form to exist. I don't claim to understand fully the theories behind it, but there's lots of reading material about them.
In place of conclusive scientific evidence, many will say that it's divine providence that allowed life to exist, that the point between no life and life is where God steps in and snaps his finger. While most will stop at that, I'm sure that science will continue to try and make sense of it, to be able to explain conclusively the concept of abiogenesis. And that's the beauty of it - a never ending pursuit for a better understanding of the world.
Sent from my iPhone using Tapatalk
-
February 27th, 2016 08:21 AM #42
Of course you have no understanding of it because even Gary Steinman who co-authored Biochemical Predistination can't answer it when confronted with the question. That's 5 years after that book was written and even Dean H. Kenyon the co-author in 1982 said that he no longer accepted the pro-evolution arguments in Biochemical Predestination.
What did they wrote in that book?
In the book, Kenyon and Steinman conclude that "Life might have been biochemically predestined by the properties of attraction that exist between its chemical parts, especially between amino acids in proteins." They argued that life originated with the chemical properties of amino acids causing them to be attracted to each other, forming long protein chains, most important in every living cell. Kenyon believed that proteins were directly formed by attraction between amino acids without DNA coding, and that these were derivatives from non-living raw chemicals in a conducive environment.Kenyon began to doubt his theory in the mid-1970s after a student posed the question to him as to how the first proteins could have been assembled without specific genetic instructions.Last edited by ClaNker; February 27th, 2016 at 08:25 AM.
-
February 27th, 2016 10:24 AM #43
Kenyon wrote a book on his theory, realized it was wrong, then succumbed to young earth creationism. Just because his grand theory wasn't solid doesn't mean that everyone else's progress is just as invalid.
Like I said, you can choose to insert divine intervention in place of a solid theory on the origin of life. But while you choose to stop at that, new theories exploring the big leap from no life to life are being studied.
The RNA world theory is perhaps the most widely accepted school of thought on abiogenesis today. It hypothesizes that before nucleic enzymes and DNA became the conduits of genetic transfer, there was RNA. Proteins are not the only molecules capable of catalysis. Catalytic RNA was discovered in the 80s (winning the 1989 Chemistry Nobel Prize). RNA can also store genetic information, so you have the basic formula for genetic replication. In line with Darwinian evolution, because of the inherent instability of RNA, life eventually evolved into DNA and proteins.
Sent from my iPhone using Tapatalk
-
Verified Tsikot Member
- Join Date
- Dec 2013
- Posts
- 680
February 27th, 2016 11:08 AM #44science is not infallible. a theory is only good until it gets debunked or a better one comes along. basically all of these are assumptions (however intelligent) trying to piece together and make sense of what we do not know/understand with whatever information is available. at this moment, none of these can explain fully how we came to be and thus rely on faith - the creationist on his creator and the scientist on theories(although with evidence) cannot be accepted fully as fact.
-
February 27th, 2016 12:17 PM #45
Neandertals are a completely different species.
If cats can always mate with cats... why can't big cats mate with small cats?
Why can't Elephants mate with other Elephants?
The close relationship of different species is direct evidence that they branched off from an ancestor species.
IF there was no evolutionary descent, there would be no reason for them to be related genetically. At all.
And you still haven't tackled why interbreeding Dolphins and False Killer Whales produces an intermediate species that is anatomically different from both (different number of teeth from both parents)
The morphological changes that separate related species will not, in themselves, make it impossible for those two to interbreed. It is the encoded DNA errors, building up over time, that will eventually separate them enough to prevent interbreeding.
Again, belief in micro-evolution means you believe in macro-evolution. You just don't accept the results.
Ang pagbalik ng comeback...
-
February 27th, 2016 06:01 PM #46The discovery that RNA possesses catalytic ability provides a potential solution: a single macromolecule could have originally carried out both replication and catalysis. RNA – which constitutes the genome of RNA viruses, and catalyzes peptide synthesis on the ribosome – could have been both the chicken and the egg! However, the following objections have been raised to the RNA world hypothesis: (i) RNA is too complex a molecule to have arisen prebiotically; (ii) RNA is inherently unstable; (iii) catalysis is a relatively rare property of long RNA sequences only; and (iv) the catalytic repertoire of RNA is too limited.
Last edited by ClaNker; February 27th, 2016 at 06:15 PM.
-
February 27th, 2016 06:05 PM #47
False killer whale scientifically belonged to the dolphin family just as Neanderthals is a subspecies of human in the genus Homo. Show me a proof that False killer whale and dolphin interbreed in the wild.
Although reports have been made about wholphins possibly living in the wild there is not enough quality information or DNA tests that exist to give a conclusive answer to whether or not wholphins live outside of captivity and if so what type of habits and behaviors they posses.
-
February 27th, 2016 06:14 PM #48
Therein lies the problem with those who believe in the so called solid science of Darwinian Evolution. You have to rely on faith that the science of Darwinian Evolution is correct just like how the Bible Creationist believe in theirs.
I do believe in science and I strongly disagree with the literal interpretation of the 6 day creation in the Book of Genesis. Science will just have to come up with a solid theory on how life began and that it's observable and testable.
-
-
February 28th, 2016 01:34 PM #50
You can show all the videos you want from creationist crankpots. But if their argument boils down to irreducible complexity, they still won't hold.
Doesn't matter if they don't do it in the wild. That it can be done at all points to distinct species being related enough to interbreed. End of story.
False Killers and dolphins are completely different species. Morphologically and genetically. Taxonomically, you would never label them dolphins. At this point, you are just relying on semantics. "Family" is different from "species" (as in, two levels of taxonomic rank different). Like versus like, old Testament writers would never classify one as the other.
And this still doesn't explain why elephants can't mate with other elephants.
There are several large genetic mutations occuring within the human genome within historical times, including, famously, lactose tolerance... which helped several waves of invasion and migration.
Also, "ages." Tell me, what percentage of "millions" is "thousands"? If certain felines and equines fail to completely speciate within a few million years, how does dog breeding, occurring over a few thousand years, disprove speciation?
Note: a horse and a donkey are two completely different species. With different numbers of chromosones. They should NOT be able to mate unless they were related via a distant ancestor.
Ang pagbalik ng comeback...