Darvin's theory in shools
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Beefstew2011 — 17 years ago(July 10, 2008 01:43 PM)
Wrong. You would make a terrible scientist. There are several possibilities outlining the origin of viruses. The reason it is so difficult to detect the common descent and origin of viruses is because it evolves (yes, evolves) so fast and is so easily demolished once dead that the oldest examples we can deal with are a few decades old.
However, we can sequence all or part of the genome of all known varieties of viruses, including the largest and smallest types. With the help of these genomes, divergence patterns can easily be drawn to determine the common ancestry and ultimate origin of viruses. The divertence of Geminiviruses have an origin that is traceable by phylogenetics to approximately 200 Mya. This is supported by geographical diversity, and genetic divergence of vectors and of plant hosts.
The same goes for Potyviruses and Bymoviruses, who spontaneously form new genome components. All cladistics in comparitive genetics and phylogenetics point to an origin with replicase associated functions of viruses with RNA genomes. DNA possesing viruses share a common origin of the reverse transcription function. This says that the early viral evolution was modular, with a number of successful core modules, such as that of the retrovirus pol gene, and picornavirus-like protease-Vpg-polymerase module appearing in several highly varying viruses.
What am I saying here? That the evolution of viruses is not DNA based, it is modularly based. This is why certain animal viruses such as picornaviruses and alphaviruses have relatives among plant viruses that don't share the same morphology, genome components, genome organisation, or number of genes. This explains why we see picornoviruses, which contain ssRNA and only a single component, have the same module as comoviruses.
In a way, viruses can be defined as organisms which can only undergo a life cycle inside the cells of a host organism using at the very least the metabolic enzymes and pathways and ribosomes of that host to produce virion components which get assembled into infectious particles.
One possibility is that endigenous retroviral DNA was able to detach itself from single cell prokaryotes that were able to sustain an independent life cycle within the cell. (Guess what! This has been observed in the lab, and in nature, countless times.) But it does not at this stage count as a virus. Eventually it became subject to natural selection because it was so independent, and thus it would be favored if the properties of the virus could lead it to be more competitive. This leads to multicellular transport, and more rapid reproduction. Viruses are the ultimate product of evolution, they only live to increase their reproductive function, therefore natural selection only selects for such a thing.
You fail at science. -
bjshipley1 — 17 years ago(September 08, 2008 08:08 AM)
This alert response would be useful for people alone in the wild, as our first two ancestors were.
That's funny, it seems to me that Adam and Eve didn't really have a need for an "alert response" seeing as how they had GOD there, and everything. I don't recall the "hiding from the predators" segment in Genesis.
The most dangerous thing in the world is a Second Lieutenant with a map and a compass. -
Rangely8723 — 15 years ago(July 10, 2010 01:58 AM)
Based on this description viruses are descended from viruses and produce other viruses. This cannot explain how viruses came into existence in the first place
The mechanisms of evolution cause a diversity of life, they have nothing to do with the origin of life
or how viruses will evolve into anything except viruses
Why should viruses evolve into something different? The suggestion that an organism has to evolve into 'something else' or into a 'more complex organism' is a strawman argument.
Et moi, je lui ferai porter la sienne comme Saint Denis -
Shuggy — 17 years ago(January 06, 2009 05:26 PM)
- One final laugh -
All frog embryos look identical, so how can it be that nearly all frogs lay eggswhile one of them, the Nectophrymoldes
That's
Nectophrynoides
. Looks like your creationist OCR isn't working very well.
occidentalis of New Guinea, brings forth its young live! This requires a womb, a placenta,
It requires no such things.
a yolk sac,
All frogs, and indeed all animals born from eggs, have yolksacs
and other modifications not found in the other frogs. Did that one frog descend from humans
Get a clue! Humans are not the only animals born alive.
or vice-versaor what did it descend from? Its embryo is just like all the other frog embryos.
Yes, to expel an egg that hatches outside the body, or to retain it in the body until after it hatches is a relatively minor modification - much more minor than you seem to imagine. Just a matter of timing.
(Another frog is a marsupial.)
Yes, you see them hopping all over the place. Duh. The pouches of frogs that have them are very different from the pouches of marsupial mammals. To evolve a pouch is a very small matter, just a change in the configuration of the skin.
You really should learn some elementary biology so as not to make such a fool of yourself.
Keanu should play Gort
and more at
www.cafepress.com/wero/4555996
- One final laugh -
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Roquefort — 16 years ago(June 14, 2009 02:17 PM)
There are sites and youtube videos that promote the idea that human chromosome 2 is a fusion of two ancestral ape chromosomes. However, one evolutionist article points out that the genes were already human at the time of this fusion.
"At the site of fusion, there is approximately 150,000 base pairs of sequence not found in chimpanzee chromosomes 2A and 2B. Additional linked copies of the PGML/FOXD/CBWD genes exist elsewhere in the human genome, particularly near the p end of chromosome 9. This suggests that a copy of these genes may have been added to the end of the ancestral 2A or 2B PRIOR to the fusion event."
http://en.wikipedia.org/wiki/Chimpanzee_genome_project -
frontiersmantanis — 16 years ago(June 18, 2009 08:49 PM)
ALL articles point out that they were already hominid chromosomes at the time of fusion, thats the point, had it been before the split between our ancestors chimps would have it too. Of course there are going to be differences, we've been diverging for 7 million years with average mutation rates at 100 per generation.
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Roquefort — 16 years ago(June 23, 2009 07:38 AM)
The articles point is: "PGML/FOXD/CBWD genes exist elsewhere in the human genome, particularly near the p end of chromosome 9."
The reason we disagree with your theory that those genes were hominid is because evolution would have been required to simultaneously and identically update regions of 2 separate chromosomes.
Hominid genes are an unnecessary assumption.
The easiest explanation is that they were human genes at the time of fusion. -
frontiersmantanis — 16 years ago(June 23, 2009 11:49 PM)
You don't disagree, you only lack understanding. No 'simultaneous updating' would have been required, genes are duplicated and shifted all the time.
It wasn't an assumption that they were hominid, it was a prediction, one that was confirmed -
Roquefort — 16 years ago(June 24, 2009 07:33 AM)
Because the end-on-end fused chromosome was so rare and difficult we can conclude:
(1) The fusion was intentional re-design,
(2) The incentive to mate bewtween the first 46/46 was because there were only two humans in existence,
(3) The reason the descendants were genetically capable of inbreeding was because there genes were newly created. -
frontiersmantanis — 16 years ago(June 24, 2009 08:26 PM)
Uh, no, telomeric fusion itself has little to no effect on gene expression. Different organisms of the same species with different chromosome counts are capable of successfully breeding because of this. New genes are continually created, its cumulative, populations evolve not individuals.
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Roquefort — 16 years ago(June 25, 2009 07:27 AM)
Telemeric fusions are from genetic redesign. In nature, end-to-end fusions result from telemeric failure and cause cell death.
Here's another little tidbit that is sure to please you.
Time magazine spent the second half of the twentieth century writing puff pieces on Lucy and the Leakey family.
Then in 09OCT06 p. 50 they tell us:
"That could explain why some of the most ancient fossils now considered human ancestors have such striking mixtures of chimp and human traits - some could actually have been hybrids." -
frontiersmantanis — 16 years ago(June 25, 2009 11:09 PM)
"Telemeric fusions are from genetic redesign."
Evidence?
"In nature, end-to-end fusions result from telemeric failure and cause cell death."
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=517405
Time is not, nor has it ever been a scientifically peer reviewed source -
Roquefort — 16 years ago(June 26, 2009 08:54 AM)
The first statement in you web referenece is :
"Terminal deletions of Drosophila chromosomes can be stably protected from end-to-end fusion despite the absence of all telomere-associated sequences."
Human chromosome 2 has an end-to-end fusion which is in nature is cell destructive.