On the Galapagos Islands, where Charles Darwin’s observations led to his evolutionary theory, scientists are now reporting that they’re witnessing a single species splitting into two, according to a new paper in the Proceedings of the National Academy of Sciences.
A husband and wife team, Peter and Rosemary Grant of Princeton University, have spent the past 36 years studying Darwin’s finches, technically know as tanagers. Darwin‘s observations of the birds during his voyage to the Galapagos on the HMS Beagle helped him arrive at the idea of evolutionary divergence: when different populations of a single species become geographically isolated, and evolve in different directions. The Grants have pushed that work further, with decades of painstaking observations providing a real-time record of evolution in action. In the PNAS paper, they describe something Darwin could only have dreamed of watching: the birth of a new species [Wired.com]. The process has been taking place with the help of a little bit of chance and a special song.
The split began in 1981 when an unusually large male finch from Santa Cruz island arrived on the island where the Grants were based, Daphne Major. The biologists tagged the bird number 5110, and followed him and his offspring through seven generations total. In the fourth generation a drought killed off all the descendants except one male and one female. These offspring became isolated because they have the avian equivalent of a strange accent. These finches learn their songs from their father, and the Grants suggest that 5110 sang the songs from his birth home of Santa Cruz then modified his come-hither ballad by roughly copying the Daphne Major birds’. This imperfect copying, they suggest, has over time acted as a barrier to interbreeding [Nature News]. So the immigrant bird’s descendants have bred only with each other for three generations.
The Grants say there’s no clear rule for when to declare a reproductively isolated population a new species, and also note that the birds descended from 5110 could still die out. But whatever happens, their legacy will remain: New species can emerge very quickly — and sometimes all it takes is a song [Wired.com].
The Grant’s are currently in Japan accepting the Kyoto Prize in basic science for their life’s work.
Related Content:
80beats: Fast-Track Evolution Gave Rise to Deer Mouse’s Pale Coat
80beats: Mosquito Invasion Could Wipe Out Galapagos’ Native Species
80beats: Couple That Saw Quick Evolution in Darwin’s Finches Wins Big Prize
Image: flickr / putneymark
November 17th, 2009 at 9:27 pm
The problem lies in how to define that is a new species
November 18th, 2009 at 2:18 am
The Galapagos finches remain finches, and some of those “species” have been seen to mate with other “species” and produce fertile offspring. I think those birds fooled Darwin into thinking he had figured out how evolution works.
November 18th, 2009 at 3:55 am
I think I saw the image of jesus in the birds feathers, must be intelligent design
November 18th, 2009 at 9:16 am
The Grants have declared speciation has occurred based on reproductive isolation alone, a criterion that is by no means universally accepted or proven accurate. Dozens of hypotheses exist to explain what constitutes speciation (the emergence of a new species) and what makes a new species. None can account for everything observed. In fact, as one commenter has pointed out already, no one knows how to define a species–which makes the whole discussion moot. Don’t announce a “new species” unless and until you can define what a species is in the first place.
Lisa A. Shiel
author of The Evolution Conspiracy
November 18th, 2009 at 10:59 am
If geographically isolated finches with accents constitute a new species of finch, are geographically isolated people groups with unique languages all different species of people?
P.S. Doesn’t this sound like a set-up for a bad joke:
“These offspring became isolated because they have the avian equivalent of a strange accent… So the immigrant bird’s descendants have bred only with each other for three generations.”
November 18th, 2009 at 11:22 am
The Galapagos Islands are the place where you can really feel and breathe the true essence of evolutionary nature
November 18th, 2009 at 12:37 pm
We would probably all agree that lions (Panthera leo) and tigers (Panthera tigris) are different species of big cats. However lions and tigers can mate to produce ligers. Female ligers can even be reproductively fertile themselves. The reason there are no ligers in the wild is because tigers and lions are ecologically and geographically isolated – their ranges don’t overlap, which creates natural non-random mating between the sub-types. Lions and tigers are still both big cats – they are just different sub-types (or species – leo or tigris) of big cats (Panthera) .
All that is happening in the Galapagos finches is that there is non-random mating occurring in a subset of finches primarily because of song selection, rather than distance – it’s the exact same concept of defining the differences between tigers and lions. The interesting question is whether this small, non-random mating set of finches will ultimately give rise to a new type of finch that will endure – they already have unusual beak width and unique genetic markers because of the non-random mating; characteristics that are used to classify existing finch species on the Galapagos. The authors correctly state that there is no guarantee this group will survive and it should be monitored further because if it does, it will document the emergence of a new distinct sub-type (species) of finch from the very beginning.
November 18th, 2009 at 12:48 pm
Like others I’m not convinced by these stories of variation within a species point to speciation. I’ve seen a number of them recently. I believe the basic evolutionary model, and I’m not interested in religious explanations of species. But what we have here is a variety – there’s no sign for instance that the new variety *can’t* breed with the others. There’s no guarantee that another environmental change might not throw them back together again.
So far as I can tell we have observed several species produce superficial varieties that are disinclined to breed, but we have never observed this getting to the point for instance where breeding is not possible, or where the offspring of a mixed variety breeding is infertile. They say there is no clear definition of species, but then why claim that this is a new species if it is not clear? They are avoiding the problem of what a species is because by any measure that I’m aware of they have one species. Geographical difference in songs is a standard feature of both birds and whales – it’s no big deal.
This kind of variation is quite normal in domestic animals but I’ve yet to see anyone describe a great-dane as a different species to a chihuahua. And yet successful breeding between them is far less likely than for these finches!
Of course it is *possible* that this kind of variation *might* result in speciation – but I’m still waiting to see one example of a clearly new species arising in this way. None cited in the article above.
A triumph for journalism, circulation figures, and research grant applications. Otherwise… meh.
November 18th, 2009 at 3:45 pm
A new species? Really?
So Hispanics with blue eyes who have a German/Mexican ancestry and live in Central Texas or Brazilian’s who have Japanese/Portuguese ancestry are a new species? One could use similar arguments to support characterization of people groups as a new species as is used in this article but it all a bunch of BS.
Until there are confirmed reports of Raccoon’s giving birth to Panthers, or Birds hatching wolverines then the type of Evolution (macro) that these micro changes are being used to support will be viewed as a myth to those who haven’t consumed the Darwin Kool-Aid.
November 18th, 2009 at 3:59 pm
“So Hispanics with blue eyes who have a German/Mexican ancestry and live in Central Texas or Brazilian’s who have Japanese/Portuguese ancestry are a new species? One could use similar arguments to support characterization of people groups as a new species …”
Absolutely not. The situation posed in this ethnic mix thought example implies correctly that there is substantial random mating in humans is occurring regardless of language, culture or geographic area of origin. The finch biologists argue that non-random mating helps define the sub-type (or species) of finch they are studying. Applying this concept to the thought example correctly argues that humans as an entire group are indeed all one species. An ‘ethnic’ Siberian tiger is still a tiger as much as an ‘ethnic’ Indian tiger is a tiger.
November 19th, 2009 at 3:56 pm
Species is definitely a tenuous concept to define. For sexual organisms, when enough generations occur in which no breeding occurs between them and their former lineage it may be considered a species. It’s almost more a probabilistic criteria: Is the likelihood of the species re-integrating with the original population significant or negligible. If it’s negligible it may be considered a new species. It’s not that breeding can’t biologically result in fertile offspring, its more about the end result. Will the two populations converge again or maintain divergent paths. Taxonomical/morphological considerations help to define species in concert with this reproduction criteria
Asexual or non-sexual reproducing organisms speciation is even more tenuous to define because reproduciton occurs via fission or self-fertilization so genes of other individuals are not mixed often. Here taxonomical/morphological considerations are primary because breeding occurs with individuals only and not between individuals so you can’t inter-breed with original populations…
Different human races certainly aren’t different species because we breed with others of various descent on a regular basis. There are no isolated gene pools. Even the Inuits get around…
November 19th, 2009 at 6:13 pm
I’m sorry, Chris, but if you want anyone to take you seriously, you need to do some studying. If we ever did get a confirmed report of a raccoon giving birth to panthers, that would be a serious blow to evolution, not a confirmation of it (and that raccoon-panther thing would NOT be macroevolution either). I’d hate to think what you must have been drinking to come up with this nonsense.
If you don’t know why this would be a blow to evolution and don’t know why this is NOT macroevolution, then you shouldn’t be posting because you do not have the necessary knowledge to have an opinion on evolution.
So go read up on what evolution actually is, and get it from actual evolutionists/biologists (not Kirk or Ray or Ken or Duane or Henry). You don’t have to agree with the experts, but if you’re going to disagree the least you can do is get your facts right, and your understanding fixed. Otherwise, you’re just another example of the Dunning-Kruger effect.
November 29th, 2009 at 3:07 pm
Hi, my names Layla Baker from Imagine Publishing. There are two new books coming out, one in August the other in September, the first Galapagos, The Untamed Isles by Pete Oxford & Renee Bish. Pete’s photographs are simply stunning and depict the wildlife in the Galapagos and it’s paired with a foreword from Graham Watkins who is a former director of the Charles Darwin Foundation. Each picture will leave you breathless from iguanas swimming in deep blue waters, to a sea lion mother with her baby and a brilliantly-colored vermilion flycatcher on Spanish moss. Besides snapshots of animals in this beautifully made book, it includes pictures of the volcanic eruption of Fernandina in the winter of 1995.
The second book, out in September, is Galapagos Both Sides of the Coin by Graham Watkins and Pete Oxford with a foreword by His Royal Highness, Prince Philip, Duke of Edinburgh. This book really gives the reader an insight into the complicated dilemmas were having with conserving the ecosystem in the Galapagos Islands. The year of 2009 is the year of Charle Darwin. From the 150th anniversary of the publication of his study that changed the world, to the 200th birthday of Darwin and the 50th anniversary of the creation of the Galapagos National Park and also the 50th anniversary of the making of the Charles Darwin Foundation. It’s also a two-sided coffee book, so that when you begin reading, its the gorgeous pictures of the islands beauty and the second section is a description of the important battle to maintain this environment.
Both of these books are simply amazing and will help understand the beauty and uniqueness of the Galapagos and how important it is to conserve its sanctity
January 11th, 2010 at 10:19 am
galapagos islands are beautiful. and the totises and seals are cute.the island has pretty flowers and plants
October 9th, 2010 at 1:50 pm
@Yosan: I totally agree. The biodiversity is amazing there.
June 1st, 2011 at 7:08 pm
@Yosan I totally agree it’s really nice and I enjoy the FROGSS there i’m sure you and carlos do to.
June 24th, 2011 at 8:15 am
Appreciation for the very helpful posting, most of us could use much more personal blogs such as this on the web. Would you expand more on the second paragraph please? I’m a little bit perplexed and undecided whether or not I understand your point entirely. Thank you.
July 27th, 2011 at 6:07 pm
I am really impressed with your writing, but as well as with this beautiful layout of your blog. Is this a paid theme or did you modify it yourself? Either way keep up the excellent quality writing, it is rare to see a nice blog like this one these days..
August 6th, 2011 at 4:10 pm
Can anyone recommend a link with more info about it?
November 30th, 2011 at 4:41 pm
Where did the larger bird come from?If it was evolution wouldn’t it be native to the island of other finches? Also ” But whatever happens, their legacy will remain: New species can emerge very quickly — and sometimes all it takes is a song” What? Are w e talking creation or evolution? Evolution is supposed be gradual. This story is more about Natural selection and not evolution. Some died of while other served to no credit of evolution.