Identical birds, different genes

November 13, 2019November 13, 2019 NewsComments(14)

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New research by the Milner Centre for Evolution academics in collaboration with Sun Yat-sen University in Guangzhou (China) shows that Southern and Northern breeding populations of plovers in China are in fact two distinct species: Kentish plover (Charadrius alexandrinus) in the North and white-faced plover (Charadrius dealbatus) in the South.
Using state-of-the-art genomics analysis, the team revealed that the Kentish plover and white-faced plover diverged approximately half a million years ago due to cycling sea level changes between the Eastern and Southern China Sea causing intermittent isolation of the two regional populations.
The results show that despite looking very similar, the two plover species have high levels of genetic divergence on their sex chromosomes, (Z chromosome) than on other chromosomes, indicating that sexual selection might play a role to in the evolution of the two species.
Dr Yang Liu, a visiting scholar from Sun Yat-sen University at the Milner Centre for Evolution, led the work. He said: “The initial divergence of the two plovers was probably triggered by the geographical isolation.
“However, other factors, such as ecological specialisations, behavioural divergence, and sexual selection could also contribute to the speciation of the two species. Paper. (open access) – Xuejing Wang, Kathryn H. Maher, Nan Zhang, Pinjia Que, Chenqing Zheng, Simin Liu, Biao Wang, Qin Huang, De Chen, Xu Yang, Zhengwang Zhang, Tamás Székely, Araxi O. Urrutia, Yang Liu. Demographic Histories and Genome-Wide Patterns of Divergence in Incipient Species of Shorebirds. Frontiers in Genetics, 2019; 10 DOI: 10.3389/fgene.2019.00919 More.

So different sets of genes can result in identical looking birds? This is getting as complicated as the butterflies.

From Jonathan Martinez at Eurekalert:

(The Kentish Plover (right) and White-faced Plover (left) are look very similar but are in fact different species. )

See also: A physicist looks at biology’s problem of “speciation” in humans

14 Replies to “Identical birds, different genes”

1

Bob O'H says:

November 14, 2019 at 2:43 am

So different sets of genes can result in identical looking birds?

That’s not what they’re saying – the genes for morphology and colour are probably the same. We don’t have convergent evolution here, rather one where colour has not diverged a lot.
2

pw says:

November 14, 2019 at 7:01 am

“the two plover species have high levels of genetic divergence on their sex chromosomes”

What about the other chromosomes, besides the Z?
3

pw says:

November 14, 2019 at 7:04 am

What does it mean “species”?

https://en.wikipedia.org/wiki/Plover
4

pw says:

November 14, 2019 at 7:08 am

“cycling sea level changes” ?

Melting ice?
5

Bob O'H says:

November 14, 2019 at 8:19 am

Pw – the divergence in the other chromosomes was about half that of the Z.
6

Latemarch says:

November 14, 2019 at 8:32 am

PW: “What does it mean “species”?”
Good question.
From the article:

“By studying recent divergence patterns, where the two species still able to reproduce with each other, we can better understand the conditions on which all species, including our own species, have evolved.”

Seems to be a rather generous (as in meaningless) definition of species if they can still reproduce with each other.
The taxonomists find finer and finer distinctions and features to claim a new species which then allows them to name it. (Taxonomists love naming things) These may be no more than local adaptions in this family of birds. No one wants to do the hard work of seeing if hybrids of these various genera will produce fertile offspring (they often do in zoos and they seem to admit it in the article). It would result in radical trimming of Darwin’s tree of life, and severely limit the taxonomists.
So Materialists/Darwinists/Neodarwinists/Evo-Devoists (pick your latest fashionable designation) need speciation. The fossil record is a bust. Whole families just show up, change little if any, and then disappear. So that leaves speciation as the bottom line evidence for evolution. If in fact it’s only adaption and the whole concept of species is in doubt where does that leave them? Thus they play fast and loose with the definition of species.
7

pw says:

November 14, 2019 at 12:23 pm

Bob O’H, Latemarch,

Thanks for the clarifying explanations.
8

pw says:

November 14, 2019 at 12:45 pm

Do those birds have the same number of chromosomes?

How do their chromosomes differ between those two populations? Different lengths, structures, loci, alleles?
9

PaV says:

November 14, 2019 at 1:04 pm

Maybe the real lesson of this discovery is that coding genes are not that important, a position that ID has taken for quite some time. That is, the ‘blueprint’ of life is not found in the coding genes–which are no more than a “material’s list,” but in the non-coding regions–you know, “junk DNA.”

ID maintained, all along, that “junk” DNA was very, very likely not going to turn out to be “junk” DNA. Of course, this is how things did turn out. This paper simply shows how malleable ‘coding genes’ can be, but that essentially they’re not ‘essential.’
10

Mimus says:

November 14, 2019 at 4:39 pm

Amusingly enough, the birds aren’t identical and the genes aren’t different (or at least, the are not genetic variants present in only one population).

Maybe the real lesson of this discovery is that coding genes are not that importan

.

Nope, paper is here, not limited to protein coding genes. (And, of course, the usual conflation of “junk DNA” and non-coding DNA is wrong).
11

ET says:

November 14, 2019 at 5:15 pm

I bet that with the right chef and the right gravy, no one could tell the two apart. They would never know they were eating two different species. 😎
12

Latemarch says:

November 14, 2019 at 7:06 pm

ET
It used to be that a guy with a sleeve tattoo was a biker that would beat you to a pulp.
Now a guy with a sleeve tattoo is a chef drizzling a raspberry balsamic vinegarette over your breast of plover.
13

pw says:

November 14, 2019 at 8:31 pm

To call them ‘genetic programs’ or ‘gene networks’ is to fuel the misconception that all the active causal determination lies in the one-dimensional DNA sequences. It doesn’t. It also lies in the three-dimensional static and dynamic structures of the cells, tissues and organs.

The postulate of a ‘genetic program’ led to the idea that an organism is fully defined by its genome, whereas in fact the inheritance of cell structure is equally important. Moreover, this structure is specific to different species.

The point is that such a ‘program’ does not lie in the DNA alone.

At the limit, when all the relevant components have been added in, the ‘program’ is the same as the function it is supposed to be programming.

Enrico Coen (Coen, 1999) put the point beautifully when he wrote: ‘Organisms are not simply manufactured according to a set of instructions. There is no easy way to separate instructions from the process of carrying them out, to distinguish plan from execution.’

‘Blueprint’ is a variation on the idea of a program. The word suffers from a similar problem to the concept of a ‘program’, which is that it can be mistaken to imply that all the information necessary for the construction of an organism lies in the DNA. This is clearly not true. The complete cell is also required, and its complex structures are inherited by self-templating. The ‘blueprint’, therefore, is the cell as a whole. But that destroys the whole idea of the genome being the full specification. It also blurs and largely nullifies the distinction between replicator and vehicle in selfish gene theory.

The genome is often described as the ‘book of life’. This was one of the colourful metaphors used when projecting the idea of sequencing the complete human genome. It was a brilliant public relations move. Who could not be intrigued by reading the ‘book of life’ and unravelling its secrets? And who could resist the promise that, within about a decade, that book would reveal how to treat cancer, heart disease, nervous diseases, diabetes, with a new era of pharmaceutical targets. As we all know, it didn’t happen. An editorial in Nature spelt this out:
‘The activity of genes is affected by many things not explicitly encoded in the genome, such as how the chromosomal material is packaged up and how it is labelled with chemical markers. Even for diseases like diabetes, which have a clear inherited component, the known genes involved seem to account for only a small proportion of the inheritance…the failure to anticipate such complexity in the genome must be blamed partly on the cosy fallacies of genetic research. After Francis Crick and James Watson cracked the riddle of DNA’s molecular structure in 1953, geneticists could not resist assuming it was all over bar the shouting. They began to see DNA as the “book of life,” which could be read like an instruction manual. It now seems that the genome might be less like a list of parts and more like the weather system, full of complicated feedbacks and interdependencies.’ (Editorial, 2010)
The ‘book of life’ represents the high watermark of the enthusiasm with which the language of neo-Darwinism was developed. Its failure to deliver the promised advances in healthcare speaks volumes.

https://jeb.biologists.org/content/jexbio/218/1/7.full.pdf
14

Latemarch says:

November 15, 2019 at 8:13 am

Pw:
Thanks for the article. Evolution beyond neo-Darwinism: a new conceptual framework by Denis Noble
Noble is one of the “Third Way” evolutionists that at least recognize that they have a causality problem. I love this quote at the end of the article

The great physicist Poincaré
pointed out, in connection with the relativity principle in physics,
that the worst philosophical errors are made by those who claim they
are not philosophers (Poincaré, 1902; Poincaré, 1968). They do so
because they don’t even recognise (sic) the existence of the conceptual
holes they fall into. Biology has its own version of those conceptual
holes.

We’ve certainly seen some of our Materialist commenters fall into some of those holes time after time.

14 Replies to “Identical birds, different genes”

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