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Chinahand

Evolutionary Science And Its Implications

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Science is an amazing thing - we have this murky idea of the past and bring vast resources from different branches of knowledge to try to understand and interpret the evidence we have.

 

To understand and date fossils you need to have an understanding of the fossils themselves, geology, comparative anatomy, ecology, radiometric dating etc etc etc.

 

And the results can genuinely change our understanding of the world.

 

This video has Polish and Swedish palentologists showing how the transitional fossils we'd found previously between fish and vertibrate animals tell only part of the tale - part of the video has them showing how Tiktaalik currently one of the earliest animals to start making the transition to the land must have had more advanced relatives. These animals' fossils have yet to be found, but their footprints have.

 

These types of discoveries will stimulate a whole new search to better understand how our ancestors conquered the land. Though they weren't the first - that honour goes to arthropods like these spider-like critters preserved in just stunning detail from 400 million year ago or so.

 

Stunning stuff!

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Amazing research has been released recently on feathered dinosaurs and their plumage.

 

Anchiornis-Huxleyi2_681017a.jpg

 

Links here and here

 

Anchiornis_fossil.jpg

 

This picture is from a really comprehensive page documenting the evolution of feathers.

 

I am just awed by the dedication and innovative thinking of the scientists which has enabled them to examine individual pigment on the fossilized feathers.

 

 

Video 2

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How did life begin? We don't really know ... but Dr Jack Szostak working at Harvard is more likely than just about anyone else to be involved in getting closer and closer to answering that question.

 

Here is a lecture by him explaining the work of his lab - collaborative, innovative science.

 

Link

 

 

I am pretty certain this has been posted before - its a less dry popularization of his work - with a great sound track!

 

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I really would like to understand what a person who thinks there are no transitional fossils thinks this lot are:

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Here's a really excellent lecture on the genome and genomic science by Ryan Gregory. I feel it does a good job explaining the science trying to understand the evolution of DNA and how that evolution has created such diversity in the living world.

 

http://www.youtube.com/watch?v=Ta8Rg4S4b7I

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Bill Nye, an American Kid's TV science populariser, debated Ken Ham of Answers in Genesis last night.

 

 

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I don’t really think a debate format is a good way to argue with creationists. It creates the misnomer that this is a subject where a debate exists - evolutionary science is not some cobbled together rough idea. Just like the theory of gravitation, the germ theory of medicine, and the theory of relativity, evolutionary science is based on a consilience of huge amounts of evidence from such areas as genetics, geology, bio-geography, comparative anatomy and the basic hard sciences of nuclear physics and chemistry. There simply is not a controversy to be debated within science over the evolution of life over billions of years with common ancestry (and some lateral gene transfer) clearly showing descent with modification. The debate lies within religion and whether it accepts or denies the findings of science and what are the consequences for society in doing that.

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Greg Laden brilliantly parodies how creationists can overwhelm an honest debater by simply bringing up irrelevant details.

 

... but this time Bill Nye pretty much held his own by using the same technique back at Ham.

 

It definitely wasn't a total disaster, but it does make me shake my head that it is still necessary in the 21st century to have science share a stage with such primitive theology as "my magic man made the world 6000 years ago and all the animals were vegetarians (even T-Rex) until sin and death entered the world and the magic man then got grumpy and wiped it all out in his global flood".

 

Sophisticated theology this is not, but Ham believes all this is central to the Christian message - Jesus died for a metaphor otherwise and that is something Ham will just not accept, hence his insistence that biblical creation has to be true - his magic book tells him, it does.

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Erm ... Chinahand is talking to himself again ... mutter mutter!

 

One really clear example of the sort of chaff creationists can throw up to create confusion in debates like this was when Ken Ham brought up radiological carbon 14 dating and how it produces different results from potassium argon dating.

 

Bill Nye clearly didn't know the basics of radiological dating and when presented with a gotcha moment by Ken Ham "why does K-Ar dating show the lava is millions of years old, but C14 dating shows the wood entombed in this lava is only 60,000 years or so old" all he could do is to try to explain how this might have happened due to plate tectonics bringing different aged materials together in the churn of the earth's crust. A reasonable off the top of his head explanation, but you could tell Nye was on the back foot.

 

It is far more likely that what really happened was that Ken Ham was, probably knowingly, distorting C14 dating to create a perception of a discrepancy where none in fact exists. These sorts of outright lies and distortions create an image that the science isn't clear. But surprise, surprise science is difficult and involved and different techniques will be better for examining different situations.

 

C14 has a half life of only about 6000 years. After 60,000 years radioactivity has basically broken down all the original C14 - half the C14 is gone after 6,000 years, three quarters after 12,000 years, seven eighths after 18,000 years etc. By 60,000 years 99.9% of the C14 has decayed.

 

Science is all about error bands - when taking a sample there is always uncertainty and so the result is bounded with a mean estimate and then upper and lower bounds. These error bands need not be linear, or evenly spread about the mean, and with C14 dating that is the case. Cosmic rays, neutrinos etc can contaminate radiological data and so whenever C14 is sampled there will always be a tiny amount of carbon14 produced from these sources. After 45-50 thousand years these sources of carbon are of the same order of magnitude as the carbon14 remaining from the original organic matter and so carbon dating cannot distinguish between them - a sample which is 50,000 years old can have the same amount of C14 as a sample which is a million years old – this carbon is not from the original organic matter but is contamination from other sources.

 

Radio-carbon dating simply looks at the ratio of Carbon14 to other isotopes. For samples younger than about 45-50 thousand years old there is a nice correlation between this ratio and the age of the sample. Therefore if you know the C14 ratio you can make a reasonable estimate of the samples age with useful error bands - ie the sample is 1200 years old plus 300 years minus 200 years. But note that the error bar isn't even. For a sample 30,000 years old the errors might be something like plus 10,000 years minus 4,000 years. The small amount of contamination from other radiological sources mean the sample could be much older (but not much younger where contamination is proportionally not as serious). After 50,000 years the lower limit essentially becomes infinite - the contamination is more significant than the original carbon.

 

This is the source of the discrepancy between the C14 dates and the Argon Potassium method highlighted by Ham in his example of organic matter entombed within basaltic lava. Argon Potassium dating involves a decay with a half life of over a billion years and so lots of the potassium 40 originally in the rock when it was formed will remain undecayed in the sample enabling it to give a dating with a reasonable error band. This is not the case with C14 which is effectively useless for dating organic matter over 50,000 years old.

 

Any scientist would know this and not use C14 dating for such old samples. Basically Ken Ham was repeatedly using a complete distortion of science to try to claim the science isn't clear, but the reality was he wasn't being honest about what the science shows.

 

It's a real shame Bill Nye didn't realize this. Ham offered up an open goal to Nye to explain how creationists misuse science for their religious aims, but he was left hand waving about geology.

 

Oh well. Overall he didn't do too badly, but he could have been even better!

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I started to watch it, China - but then I saw the two and three-quarter hour time on it! Spending that amount of time watching a debate like that just isn't worthwhile for me. Sorry.

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I watched the whole thing, and what I took away from it was this.

 

Science (and I mean real science) is about asking a question and then looking for the answer.

 

Creation Science (and I use the term science in this instance loosely) is about starting with an answer and making the question fit it.

 

It is a shame the Bill Nye didn't get to quiz Ham about the civilisations that pre-date Christianity's version of history, or how 8 people could shovel several thousands "kinds" of animals (times two) waste and feed said animals whilst crewing a vessel far larger than any other vessel in any comparable version of that era, or how could the entire species of man derive from just two people, or where the Egyptians came from if the flood had scoured the Earth, etc, etc.

 

It is a shame that the debate had to happen in the first place. As long as people like Ham, and the people that fund him exist, we as a global society will never reach our true potential, while we are confusing ourselves with a man made text that has no basis in fact or science.

 

It was very telling that when asked "what would change your view", Nye responded "evidence" whilst Ham replied "nothing". How can the man call himself a scientist of any description if he holds such a narrow view of existence that he can simple answer "God did it"?

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Lord of the Isles has posted this post in the "Does a God exist?" Thread.

Me being me, I thought it would be better to address it here than derail that particular thread. Arrogant or what hey!!

The 44 reasons claiming evolution is a fairy tale aren't really 44 reasons - they repeat all over the place and really really distort the science of evolution.

I'm pretty willing to have a go at explaining any of the so called 44 reasons, but I thought a good place to start would be the coelacanth.

Coelacanths have evolved lots over time, and their evolution has produced loads of transitions from species to species:

coelacanth_fossils-500x832.png
The evolution of the coelacanth is pretty well documented both via its fossils and its DNA.

As ever with evolution it isn't a linear process of one species turning into another one species, but a radiation like a bush with lots of diversity and alteration in a basic morphology. Look at the size changes over time as different coelacanth species diverge with some less than 10cm in size and others over 2 metres.

Natural Selection will happen where ever you have inheritance with variation between parents and offspring and an environment which where some offspring will survive better than others. That is a basic fact of nature and Darwin summed it up very succinctly as a logical argument:

If during the long course of ages and under varying conditions of life, organic beings vary at all in the several parts of their organisations, and I think this cannot be disputed, if their be, owing to the high geometric powers of increase of each species, at some age, season, or year, a severe struggle for life, and this certainly cannot be disputed; … [and] if variations useful to any organic being do occur, assuredly individuals thus characterised will have the best chance of being preserved in the struggle of life; and from this strong principle of inheritance they will tend to produce offspring similarly characterised. This is the principle of preservation, I have called, for the sake of brevity, Natural Selection.

I always find it wierd when creationists claim there is no way to add information in DNA. It really shows such a huge misunderstanding of how DNA works.

DNA isn't a plan, it is a recipe book, and a really messy recipe book. It’s a bit like a recipe for a cake where, as well as instructions to add two cups of sugar at this stage, and mix in the raisins at that, it also has statements saying things like “ignore the next two paragraphs of this recipe” which is followed by an section of instructions which in some cases is reasonably clear and in others degraded and of various degrees of incoherence.

Of course, this analogy is only an approximation, but it does give a flavour of what DNA is like. DNA is like a recipe that is written on lots and lots of pieces of card and you receive half the cards from your mum and half from your dad and every time an egg or a sperm is either formed or merge together there is a chance a few cards of the recipe may be left out, or copied twice, or moved from one part of the recipe to another, or the words or letters in the cards might be changed. Just think about that - if you were making a cake, and following a recipe and half way through making you suddenly find yourself repeating a card from earlier in the recipe, or "nuts" becomes "newts" do you think that would change the cake?

Now in the vast majority of cases such a recipe will be horrible and will never be used again. In other words the offspring made with that recipe will die before they can reproduce themselves and so their recipe has no chance to be made again. But every now and then the recipe will be just as good, or even better than the original - so what if it has 2 sets of raisins in it, or if it's a wedding cake, it has an extra tier.


These different cake recipes have different levels of complexity and the only recipes that continue to be used are those that taste good. All the other ones are thrown away.

That is how DNA and natural selection allows species to diverge - and definitely species diverge and transition.

Where is the transition from ape to man in this set of fossils? And many more skulls have been found since this picture was taken (see the fossil skulls in the background in this

):

fossils.png

Edited by Chinahand
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Saw this News report on IOMToday and thought I'd pass it on:

 

Link

 

Resident’s theory of evolution advances after US professor’s visit

 

Leading American geneticist-microbiologist Professor James Shapiro visited Port Erin last week to discuss resident Don Williamson’s theory of evolution through hybridisation.

 

Retired marine biologist Don, 93, stumbled on his controversial theory of evolution – in which he postulates that evolution also occurs through hybridisation – in 1983 while lecturing at the Port Erin Marine Laboratory.

 

However, he has battled ever since to gain acceptance of his theory from within the scientific community.

 

A great proponent of his theory was Lynn Margulis, professor at the University of Massachusetts Amherst. Lynn talked about Don’s work with Professor Shapiro, from the University of Chicago. And this, according to Jim, inspired him to come to the island to ‘learn more about Don’s thinking’.

 

He added: ‘Don knows about animals in nature and the wild. Validation of his ideas will come from molecular studies.’

 

Don said: ‘Jim and I approach evolution from different angles: he studies bacteria while I study animals. But we agree that evolution is much more complex than Darwin envisaged.’

 

James Shapiro is a pretty important, if controversial, scientist. It's great he's come to the Island.

 

Did he give a talk or anything else during his visit?

 

Hybridization & endosymbiosis are huge topics in evolutionary genetics.

 

As is lateral gene transfer.

 

With gene sequencing there is an avalanche of new data allowing evidence to prove the various theories out there concerning life's diversity.

 

I'm currently reading Vital Question by Nick Lane and it syntheses a huge amount of the science this data avalanche has created into an explanation of the initial origins of life and also the reason why eukaryotes (plants, fungi and animals) are so much more complex in their structure than bacteria and archeobacteria.

 

Endosymbiosis is a big part of that explanation.

 

It is an amazing fact that animals are a tiny tiny segment of the genetic diversity of life on Earth - and there sudden evolution is an active area of study.

 

It is the red area in the diagram below.

 

tmp.jpeg

 

 

It sort of puts us into perspective!

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Population genetics is one fascinating subject.

 

It has been able to explain why evolution is far more than just natural selection - with neutral and nearly neutral genetic drift being shown to be a far more powerful cause of change in a population's genetic make up than Darwinian natural selection.

 

It also has various vital uses in every day medicine - finding matches for people needing transplants; and is used to identify criminals and such like in forensic science.

 

It is a hugely wide ranging practical science showing the relationships throughout life.

 

A new paper has just been published in Nature looking at the DNA sequences of Humans, Neanderthals, Denisovians and Chimpanzees.

 

The results tell an amazing story of human migration out of Africa of the last 100,000 years or so.

 

a.jpg

 

Mathew Cobb has written a guest piece on Prof Jerry Coyne's site, Why Evolution is True, explaining how back in the early days of human evolution a wave of modern humans left Africa, but failed to colonize the world. Originally it was thought they died out completely, but traces of their DNA has been found in Neanderthal bones from the Altai mountains, with whom these early humans interbred before dying out. About 65,000 years ago a later more successful wave of humans emerged from Africa and successfully colonized the world. They interbred with Neanderthals at various places around Eurasia, with the Neanderthal genes that entered the human lineage having a lasting legacy with Genetic related diseases.

 

I just find it amazing how we can explore our origins by looking at how our genetics compares with people living elsewhere around the world and the ancient bones found by archaeologists.

 

Enjoy the links!

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