Question from Facebook about the extinct bird that re-emerged


(Christy Hemphill) #1

This article was posted on the BL FB page.

Steve wrote in with this question:

Ok. We are going to assume this article is 100% right. They have all their fossils in a row. They have their time line right on the year. You read through - 136,000 years ago this island in the ocean submerged. Then all the bird stuff. Now, here and now the island is in danger of submerging again due to global warming. Ok, we believed everything so far - what caused it to submerge 136,000 years ago?

Can anyone help him out?


(Phil) #2

Good question, and suspect it was due to the ups and downs of tectonic shifts, or perhaps rising sea levels covering it with ice age melting and gradual rise bringing it back above the water, but will let others answer that. My question with the article was that the headline is a little misleading, in that I would not say the same species arose, but rather that a similar species arose due to convergent evolution. Of course, I am sure that DNA is not present from the first, but it would be fascinating to compare the two if you could.


(RiderOnTheClouds) #3

How would you respond to this tweet (check out the ridiculous following tweets in the thread as well):

I am worried that Dr Heiser’s climate change denialist may be influencing him here.


(Stephen Matheson) #4

Sea levels fluctuate dramatically over scales of tens of thousands of years. Our current sea level is hundreds of meters higher than it was just 8000-9000 years ago, when an entire civilization occupied what is now the bed of the North Sea. (That’s just an example.) As glaciation rises and falls over millenia, so too does sea level. I don’t know about the specific example mentioned in the OP, but there is nothing remarkable about such huge changes in sea level.


#5

I have no idea who he is, but to be honest this story did make me think of the coelacanth as well. Of course, my primary introduction to the coelacanth was from YEC literature that used it as a “proof” that evolutionary claims were bogus, so that might be where the association came from.


(Randy) #6

Yes and the forces affecting the coelacanth are way different from the bird. I, too, have had such “foot in mouth” moments.


(Matthew Pevarnik) #7

Did he bother reading the paper?

Probably not. This tweet sounds like something Richard Dawkins would say when speaking about Mike Heiser’s area of expertise.


(Matthew Pevarnik) #8

Me too sadly lol. Anyways this was a nice refresher on the topic:

Part of the blog post is from this paper:
http://www.legs.cnrs-gif.fr/wp-content/uploads/2014/02/Casane_Bioessays_2013_coelacanths.pdf


(Chris) #9

From UD

Note that loss of the ability to fly is treated in this story as a form of evolution, as if the loss resulted in greater complexity rather than less. As if it wasn’t fatal when the island was inundated. But it enables evolutionary biologists to say that “evolution happened.”


(Phil) #10

Evolution is change, and that change is often not new function. There is cost associated to the organism whenever something like wings are present, and evidently it is of benefit to the bird to not put the energy into growing wings when they are not needed. I am not sure why some assert that evolution must result in more complexity, and often the same people deny vestigial structures, which I suppose is consistent.


(Matthew Pevarnik) #11

Righto. Just like how whales and other cetaceans lost many genes for hearing above water, some lost genes for making enamel in teeth, and other types of ‘losses’ that led to ‘macro-evolutionary’ changes over time.


(Chris) #12

However the core hypothesis of the [Neo-]Darwinian theory of evolution is that

… as a consequence to Natural Selection, entailing
Divergence of Character and the Extinction of less-improved forms.
Thus, from the war of nature, from famine and death, the most
exalted object which we are capable of conceiving, namely, the
production of the higher animals, directly follows. There is
grandeur in this view of life, with its several powers, having been
originally breathed by the Creator into a few forms or into one; and
that, whilst this planet has gone cycling on according to the fixed
law of gravity, from so simple a beginning endless forms most
beautiful and most wonderful have been, and are being evolved.
Page 359 , Origin of Species, The - Charles Darwin

In other words it supposes that evolution began with a simple microbe and by the accumulation of many slight gains it eventually produced man. So evidence for evolution must demonstrate the accumulation of functional gains, and conversely evidence of loss of function would be evidence against it.

If you are arguing for mankind to microbes evolution then indeed this would be supporting evidence.


(Chris) #13

If! It is far from being established that this is so and the very short window between the last land animal and the first true whale as shown from the fossil record, together with the number of changes that need evolve and be fixed for this to happen makes this impossible in practice. To argue that gain of function mutations must have occurred to produce an assumed evolutionary descent is begging the question.


(Phil) #14

Alas, but your perspective is limited to what you judge to be progress. The wingless bird is better adapted to the conditions it lives in, thus is more advanced. Your thoughts would be somewhat like saying modern cars have lost functional ashtrays, thus are inferior and have lost complexity compared to a 1963 Impala.
In addition, a quote from Darwin 150 years ago hardly reflects current knowledge and the state of science today, no matter how insightful it was at the time.


(Matthew Pevarnik) #15

Unfortunately the transition from on land back to the seas has only gotten stronger with evidence.

How short is short @aarceng?

What kinds of changes need to occur? Specifically and from a genetic standpoint? Or we can even begin with a morphological standpoint with anatomical changes?


(T J Runyon) #16

D’oh!


(Chris) #17

You are conflating function and benefit. A loss of function can be beneficial as it is here.


(Phil) #18

Or perhaps we are conflating complexity with benefit. A less complex entity can be more advanced. Of course, the loss of wings could also be more complex as well, as additional changes have to take place in order to suppress wing development. Those genes don’t just disappear, they are just not expressed, and additional changes have to take place regarding muscle attachments, etc. which may actually mean more molecular complexity to produce functional simplicity.


(Chris) #19

Interesting speculation. I wonder if examination of the existing rails would support it. Are you suggesting that the genes are silenced epigenetically rather than being defective, and what is the evidence? Do there have to be changes in muscle attachments and what is the evidence? Perhaps there is just atrophy without changes in attachment?

My speculation is that after flight became unnecessary on the island there was no purifying selection to maintain flight and so defects would accumulate eventually making them flightless. From an evolutionary perspective this is a much more likely scenario.


(Christy Hemphill) closed #20

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