
Galapagos finches caught in act of becoming new species - sohkamyung
http://www.bbc.com/news/science-environment-42103058
======
onychomys
For those who are scientifically minded but not biologists, I highly recommend
the Grant's "How and Why Species Multiply" [0]. It's very well written. If
you're much more into population dynamics, you could give their book "Ecology
and Evolution of Darwin's Finches" [1] a look. It's much more technical, being
aimed at maybe upper level undergrads (in evolutionary bio) or so. They have
another book, "40 Years of Evolution: Darwin's Finches on Daphne Major
Island", but I haven't read that one yet. Guess I should put it on my amazon
wishlist!

[0] [https://www.amazon.com/How-Why-Species-Multiply-
Evolutionary...](https://www.amazon.com/How-Why-Species-Multiply-
Evolutionary/dp/0691149992/ref=sr_1_1)

[1] [https://www.amazon.com/Ecology-Evolution-Darwins-Finches-
Pet...](https://www.amazon.com/Ecology-Evolution-Darwins-Finches-
Peter/dp/0691048665/ref=asap_bc)

------
speps
Most interesting part for me:

"And in this paper, new genetic evidence shows that after two generations,
there was complete reproductive isolation from the native birds. As a result,
they are now reproductively - and genetically - isolated. So they have been
breeding exclusively with each other over the years."

------
PeterStuer
If you have never read "The Beak of the Finch: A Story of Evolution in Our
Time" [1], do yourself a favor and get a copy asap. Not only is it a realy
good read on the work of the Grants and their team, it is one of the very best
pop-science books I have ever read. [1] [https://www.amazon.com/Beak-Finch-
Story-Evolution-Time/dp/06...](https://www.amazon.com/Beak-Finch-Story-
Evolution-Time/dp/067973337X)

------
dekhn
I was gobsmacked when I asked as a postdoc: "How do new species evolve" and
was told: "something something physical seperation between breeding
populations leading to breeding incompatibilities, but we don't really know
something something"

~~~
EGreg
Exactly. The biggest real example I know of is ring species. Everything else
seems to be total handwaving. In fact "evolution" is just an umbrella term for
many different theories about how speciation happens.

I have no problem with the theory of common ancestry. That has a lot of proof.
But the idea that speciation happens EXCLUSIVELY by random mutation and
"natural selection" is just handwaving theorizing. It's super hard to prove
and we haven't even begun to get close to what constitutes as a proof. It's on
the level of ancient people thinking the ONLY way to get fire is by rubbing
some sticks together.

And yet I see the latter ("natural selection") being used by many in the
scientific community to suppress other theories even though it is completely
handwavy and vague. That _is_ bullying.

Basically common descent can be rigorously defined and shown. The PROCESS by
which speciation happens is poorly understood and has been a subject of much
posturing by the scientific community (including popularizers like Dawkins)
for decades.

(PS: if you're going to knee jerk downvote this because it criticizes
"evolution", at least address it with substance.)

~~~
Retric
What is your specific objection?

Their is plenty of examples where even short term separation results in
population drift: EX: Skin tone among native Americans is unique even with
only ~1,000 generations separating the land bridge from modern times.

In the short term this may be adaptation to a new envornment but eventually
random mutation takes over.

Their is evidence that closely related members may have difficulty breading
with anything from 1% reductions in fertility to 99%. Which arguably makes
them the same species as they can still in theory breed.

However, adaptation can make it's own issues. Grizzly's + Polar bears is a
solid example where offspring is fertile but poorly adapted to either of their
parents environment.

So, now you have examples of drops in fertility and reductions in reproductive
success as populations are separated. Nothing is going to stop this process
from hitting zero net fertility and thus a new species.

~~~
EGreg
My objection is just that: genetic drift != speciation. They are still
completely interfertile with Europeans after 1000 generstions! Yet here we
have a breathless article reporting noting more than an existing male from a
"separate species", which is in fact interfertile and had viable offspring, as
being proof of "evolution"!

We don't know how speciation happens, and many people including scientists use
a lot of unscientific "just so" stories.

To claim we know that every instance of speciation happens through 1. _random_
mutation and 2. "natural selection", a catch-all term which is not well-
defined and signifies very little, is not very scientific. But worse than
that, it is then conflated with the theory of common descent, and the emergent
sociological result is that many scientists and non-scientists constantly co-
opt the word "evolution" to say "evolution is true and creationism is
therefore false" or whatever. There have been different theories such as
punctuated equilibria but we don't actually KNOW how speciation happens. It's
all posturing and catch-all terms.

~~~
Retric
1,000 generations is an incredibly short period ed: genetically. Dinosaurs to
people is ~20,000,000 generations depending on changes in reproductive cycles
likely significantly more than that.

The shocking thing is how many differences showed up not that we are still
mostly though again not 100% comparable. Remember, fertility treatments among
young people are a thing and incompatibility first shows up as an increase in
the natural abortion (miscarriage) rate ~(30% to 50%). You can find set's of
people such that A/B and C/D are more fertile than A/D or C/B.

~~~
EGreg
Right, but how do you get from that, say, to cats and dogs? Or the evolution
of wings?

In the former, you need to have some sort of event that separates the
populations for millions of generations or they'd constantly be interbreeding.
But allopatric speciation examples are few and far between. OR, you know,
there could be ANOTHER mechanism besides random mutation and "natural
selection" (handwavy term) that causes speciation.

In the latter, how a morphological feature came to evolve when the
intermediate steps would have most likely been valleys in the fitness function
is an interesting question. Proto-wings do not seem to confer any evolutionary
advantage other than the speculative one trotted out by people who _must_ have
the development of morphological features proceed ONLY by random mutation and
natural selection.

No one is disputing those two things take place. The question is whether they
explain ALL SPECIATION.

~~~
Retric
Many kinds of protowings are useful and currently exist.

Feathers for example provide great insulation.

Flying squirrels demonstrate another example. Important to note with flying
squirrel vs bats is being even slightly better at flying is useful for
squirrels. From their being slightly better at falling to flight is a steady
improvement. Even normal squirrels splay their hips sideways to catch air and
glide somewhat: [http://feedingnature.com/how-high-can-a-squirrel-jump-off-
th...](http://feedingnature.com/how-high-can-a-squirrel-jump-off-the-ground/)
Even their tails get into the act.

Flying fish similarly benefit from jumping out of the water, as part of a
continuum of other fish that jump slightly further than normal out of the
water etc.

Even seemingly useless stubby wings provide for threat displays like a Cobra's
hood. Aka, I can make my self look bigger without needing to grow big.

Evolution is often just as much about removing things as adding. So,
intermediate form may look clunky and then get cleaned up at a local optimum.

PS: Insects provide some great examples of wings with various amounts of
utility.

------
phkahler
So these "new" birds are distinct from all the other birds on the island that
they form a separate breeding group. But how distinct are they from the
outsider that started it all? Would they breed with birds from that birds home
island? If so, I'd say they're not really a new species but a displaced
species that survived one generation of interbreeding with the locals.

While certainly interesting, I wouldn't say this is a great example of
speciation. One might even argue that it's an invasive species.

~~~
bsmithers
Whether or not the speciation is "complete" is not really the point - the
title of the article says they are "...caught in the act of becoming new
species" \- in fact the article highlights the difficulty in stating what
determines something to be a separate species.

~~~
phkahler
I'm just saying they may well be an outside species as opposed to a new one.
There is certainly no new genetic material or variation that arose.

------
hayksaakian
I learned in high school that species are distinct when group B can no longer
produce viable offspring with group A.

Is it more complex than that?

~~~
sago
Yes very much so. And in fact you could already tell that that was not going
to be the right answer, because also in high school, you learned that some
species don't reproduce sexually.

In fact even within sexual species there are a whole range of reproductive
incompatabilities: from anatomical incompatibility, to impossible
fertilisation, developmental dead-ends, through to live but infertile
offspring, and seemingly viable offspring with dramatically lower
environmental fitness. Species are an organising model, very useful in a lot
of biological reasoning, but they are not a biological absolute.

In general, whenever you were taught something black-and-white with hard
boundaries in high school science, they were probably oversimplifying.

------
Knufen
So deniers of evolution will finally stop?

~~~
jdavis703
No, there are still plenty of people who sincerely believe in a flat Earth,
that vaccines are a conspiracy, and that homeopathic "treatments" make them
better. Best to move on and not worry about people who chose not to have
evidence-based beliefs.

~~~
dankohn1
Homeopathic treatments help lots of people. The trick would be to demonstrate
that they help people more than a placebo.

[https://en.wikipedia.org/wiki/Placebo#How_the_Placebo_effect...](https://en.wikipedia.org/wiki/Placebo#How_the_Placebo_effect_works)

~~~
whatshisface
The placebo effect is to a large extent due to regression to the mean, i.e. a
statistical glitch that has nothing to do with health outcomes.

[1][http://www.dcscience.net/2015/12/11/placebo-effects-are-
weak...](http://www.dcscience.net/2015/12/11/placebo-effects-are-weak-
regression-to-the-mean-is-the-main-reason-ineffective-treatments-appear-to-
work/)

[2][https://www.ncbi.nlm.nih.gov/pubmed/6369471](https://www.ncbi.nlm.nih.gov/pubmed/6369471)

~~~
DonHopkins
<spock>Tricorder readings report fascinating regressions.</spock>

"Statistical regression to the mean predicts that patients selected for
abnormalcy will, on the average, tend to improve. We argue that most
improvements attributed to the placebo effect are actually instances of
statistical regression."

<bones>I'm a doctor, not a faith healer!</bones>

"Thus, we urge caution in interpreting patient improvements as causal effects
of our actions and should avoid the conceit of assuming that our personal
presence has strong healing powers."

<kirk>You're a healer, there's a patient. That's an order.</kirk>

<scott>Now, you're an engineer!</scott>

------
fiatjaf
So hybridization is now the canonical mechanism through which new species
arise?

I thought it was autonomous mutation plus natural selection.

~~~
rf15
Maybe we have to face the fact that there's multiple ways to reach a solution
and no single canonical mechanism. (essentially the point of the article)

------
EGreg
One point is super confusing in this article, and also gives massive fodder to
critics of evolution:

 _" We tend not to argue about what defines a species anymore, because that
doesn't get you anywhere," said Prof Butlin. What he says is more interesting
is understanding the role that hybridisation can have in the process of
creating new species, which is why this observation of Galapagos finches is so
important._

If you can't define what a species is, how can you talk about the process of
creating new ones?

It seems they should be talking about the rate of gene flow between groups.
"Genetically distinct" means very little because phenotypes can vary widely
and still interbreed. Look at dogs, for example.

I would like to see more examples of allopatric speciation or other
speciation. What they have here so far is reduced gene flow to a group of
finches. Proving that none of them CAN interbreed with females is not so easy,
as anecdotal evidence of females not recognizing songs of males doesn't cut
it.

It's a bit like proving that an animal species has truly homosexual
individuals. None of them do (except possibly for domesticated sheep) -- in
fact the theory of evolution would predict that homosexuality would greatly
reduce fitness, but there COULD be some members that are lifelong homosexuals,
same as beta wolves etc. However to PROVE that an organism is exclusively
homosexual they would need to carefuly watch it and all its pairings, however
brief, its whole life.

Now, with species, you have to watch EVERY male with EVERY female around it,
and vice versa. That is a huge undertaking and I doubt they did it here.

All they observed is phenotypical differences. And they haven't really
explained how this is different from eg dogs, except to say that the females
THEY SAW did not prefer the males' songs. Certainly this shows reduced gene
flow due to preferences but not that they aren't interfertile. This is much
different than a cat and a dog for example.

What I am ultimately trying to say is, I am quite skeptical that we have
discovered ALL the means by which speciation occurs.

You can be a creationist or whatever else you'd like to be at this point. We
barely understand how speciation really takes place, in the end we still only
have theories.

I have read Lee Spetner's book "Not by Chance" which goes into the mathematics
of speciation occurring exclusively by random mutation and natural selection.
And it is astronomically improbable on its own terms.

This there HAVE to be forcing processes from the outside which we don't know
about yet. We only guess into what they could be.

And on a related note, using evolution to explain behaviors and traits is like
a religion, full of "just so" stories, in fields such as evolutionary
psychology but also to explain pretty much ANY trait in a genetic fitness
framework.

These "just so" stories are so pervasive yet smack of a notoriously
unscientific practice and framework. All one has to do is concoct a _possible_
way by which a trait (proto-wings, homosexuality, men becoming sleepy after an
orgasm -- anything really) _might_ confer some advantage. And the other way,
such "just so" stories are used to "explain" the presence of certain traits as
"the evolution of those traits" via totally untestable stories about the past.

