Posted on 09/30/2005 9:17:27 AM PDT by bigmac0707
A scientist has described a spider that was trapped and preserved in amber 20 million years ago.
Palaeontologist Dr David Penney, of the University of Manchester, found the 4cm long by 2cm wide fossil during a visit to a museum in the Dominican Republic.
Since the discovery two years ago, he has used droplets of blood in the amber to reveal the age of the specimen.
It is thought to be the first time spider blood has been found in amber and scientists hope to extract its DNA.
Dr Penney, of the School of Earth, Atmospheric and Environmental Sciences, said he had used the blood droplets to trace how, when and where the spider died.
It is a new species from the Filistatidae family commonly found in South America and the Caribbean.
Dr Penney believes it was climbing up a tree 20 million years ago when it was hit on the head by fast flowing resin, became engulfed in the resin and died.
He claims the shape and position of the blood droplets revealed which direction the spider was travelling in and which of its legs broke first.
"It's amazing to think that a single piece of amber with a single spider in it can open up a window into what was going on 20 million years ago," he said.
"By analysing the position of the spider's body in relation to the droplets of blood in the amber we are able to determine how it died, which direction it was travelling in and even how fast it was moving."
He first saw the fossil during a visit to the Museo del Ambar Dominicano, in Puerto Plata, Dominican Republic.
Dr Penney reports his findings in the latest issue of the journal Palaeontology.
1. "Aimless drift" of DNA is also evolution.
No, it is not. There is a lot of DNA that (appears to) to do nothing. Note, this IS a related concept, in that you can track the evolution of a species by looking at similarities in the junk DNA --- the idea being that there is no pressure to change the junk, so if the same exact sequences of junk (which serves no purpose and appears to be random, remember) appears in two species, then that is some evidence that the two species likely had a common ancestor species (or one species was the ancestor of the other.)
For example, certain primates and humans share similar unique "junk" DNA, which SOME opine is SOME evidence of common ancestor.
2. " . . . and the DNA were the same as some modern species, some fundamental assumption of the theory of evolution would be proven wrong."
No, it would not. Time does not necessarily equate to evoltion (although it often does corrolate). If there is no predator, competitor, disease, envirnomental change, happenstance isolation, or whatnot to force a change, there will be no change --- there is no "pressure" to change.
That is the fundamental basis of the evolutionary theory --- no pressure, no change. Pressure, change.
That said, this is an entirely new species of nasty spider, and, just looking at morphology (shape) the DNA will be different than the species of spider that are alive today, so the dispute is moot.
GOD even has a sense of humor - he created you didn't he?
:>) Ok - old joke that hasn't gotten better with age.
Actually for some damned reason, My fingers start typing in reverse order - but only on certain letter combinations. I also usually type "THe" instead of "The" now. A neurological slowdown on one side of my body - to be technical about it.
> There are many parts of the Bible not suitable for young children.
Basically the Old Testament. A child reading that as a fairy tale... fine. But if they are taught that it's literal truth, it'll mess 'em up for life.
"A child reading that as a fairy tale... fine. But if they are taught that it's literal truth, it'll mess 'em up for life."
Oh, I turned out OK.
It's the common agenda and spin and pre-conceptions of so many that make a "literal" reading dangerous --- none of which are found in a fair reading of the Bible.
From here we see that "aimless" changes are not excluded.
In biology, evolution is the process by which populations of organisms acquire and pass on novel traits from generation to generation, affecting the overall makeup of the population and even leading to the emergence of new species.
From here we see that "aimless" changes are explicitly included.
Genetic drift is a contributing factor in biological evolution, in which traits which do not affect reproductive fitness change in a population over time. Whereas natural selection causes traits to become more prevalent when they contribute to fitness, or eliminates those which harm it, genetic drift is a somewhat random process which affects traits that are more neutral.
That said, this is an entirely new species of nasty spider,
Not an expert here. What are the characteristics that lead you say it's a new species?
"novel TRAITS from generation to generation, affecting the overall makeup of the population and even leading to the emergence of new species."
"Junk" DNA does not cause any trait or have any outward expression of any kind; no proteins made, no skin color, nothing. (Not talking about blue eyes or some largely fitness-irrelevant trait --- talking about purely irrelevant DNA noise.)
"What are the characteristics that lead you say it's a new species?"
The article said it was "a new species from the Filistatidae family."
Looking in my posts for where I said anything about "junk" DNA .... nope, not there. I do see where *you* started talking about it though.
If it was 4km X 2km, then this thread wouldn't be such a waste of bits and bandwidth.
Of course you didn't first mention "nonexpressive regions of the genome" (aka junk) because your fist post had, as an underlying posit (known or unknown to you) that genetic drift was necessarily evolutionary.
This belief was not true, as explained, by the very existence of non-expressive regions of the genome, which can drift, but don't generally don't do anything when they do.
Sorry you missed the bit about "new species" in the original article, as well.
Actually, all the posters are worshipping Freya by posting on Friday.
Also, I did not miss the "new species" claim in the article, but it has no explanation of the claim. Since you mentioned "just looking at morphology," I assumed you might actually know why. My bad, I'll know better next time.
You made your mistake in Post 130.
Again, aimless drift of non-expressive portions of DNA (junk) is not evolutionary by definition, as the DNA does nothing. It's just a handy marker.
You brought in the concept of genetic drift of fairly neutral items (say spot patterns or somesuch), which is also similarly fairly aimless, but can result in distict species when several are collected on top of each other.
These "nuetral" changes are only evolutionary, however, if you have pressure in the form of GENETIC ISOLATION (which is No. 3 or so on the list of "pressures" I listed in an earlier post). Otherwise, the you have matings with others of its kind that do not have a disproportionate amount of the trait(s) at issue and the "nuetral" variations are not reinforced.
No genetic isolation (the pressure), no evolution into a distinct species from such factors.
So, no you are still wrong.
"Since you mentioned "just looking at morphology," I assumed you might actually know why."
I did, actually, but the article was a more direct.
The Filistatidae family are called "crevice weavers." I know because I had them in a tree. They are tiny, about 2 to 4 mm in size.
This was a monster in comparison.
*
As for what "mistake" you perceive in my #130, I suppose what you are missing is that "evolutionary theory implies X" and "X is an example of evolution" are not the same meaning. It is a trivial application of evolutionary logic that the genomes of 20M year old and current organisms will differ by at least 20M years of change. This will occur in both expressed and unexpressed DNA although the "clocks" will be different depending on selection pressures on the expressed DNA.
Hmmm, OK, they're bigger. Thanks.
After Saturn Sate?
You don't put up a Saturnalia tree in your house? ; )
if you stamp and shout hard enough you might convince yourself that the world is flat.
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