Forget Sesame Street, scientists pretty much watched Big Bird evolve on Galápagos island New research has documented a species of finch evolving on the Galápagos island of Daphne Major, 1,000km off the west coast of Ecuador, in just two generations. It's called the "Big Bird" lineage because, um, as finches go, the birds are relatively large. The work, led by Uppsala University's Sangeet Lamichaney with Princeton …
"in order to be considered a different species, the most important factor was cross-fertility, not mating habits."
What TFA didn't say is that the different song is a factor in mating habits. The two lots of finches don't recognise each other as being the same species. If the Big Bird species survives there'll eventually be sufficient genetic drift to break cross-fertility even if it technically exists at present.
Hybridisation has been recorded as a factor in speciation before, e.g. Spartina anglica.
Deciding whether two things are a separate species are not is a black art. Taxonomists can be regarded as two separate species, lumpers and splitters or as two sub-species of Homo sapiens.
that for speciation to be considered complete, it required genetic incompatibility, not simply habitual mating practice. My tutor was of the opinion that so-called 'lock and key' mechanisms were obviously strong contributors to speciation, but because populations could re-converge and re-hybridise, they did not satisfy the proper conditions for speciation. The 'lock-and-key' hypothesis is best exemplified by reference to the erm... 'physical' compatibility or not of the erm... anatomical components required to effect gamete transfer. Indeed some of the videos I've seen on the internet would suggest that can happen in Homo sapiens as well. As for the IT angle... have you ever tried jamming a USB cable into a Firewire port?
The professor I had for Evolutionary Biology was John Maynard Smith, by the way,
@ratfox - Breeds of cats or dogs are genetic populations that breed true to a breed standard. But they are not separate species. The mixed breed or mutts are just that. It takes several generations to develop a breed not 2.
Some domestic cat breeds have wild cat ancestry. Bengals, Serengetis, and Savannahs have an F0 cross between a wild cat species and the domestic cat (specific breeds actually). The cross is fertile enough that some of the kittens can be bred with a domestic cat producing another generation. Depending on jurisdiction one can legally own one of F0 descendants around F4 or F5. The cat is considered a domestic cat for legal purposes and acts like a domestic cat.
The problem is the somewhat sloppy definition of a species.
The problem is that the idea of a species is almost prescientific and arose before modern genetics. To use an analogy which may be illuminating but is probably totally wrong, it's like someone attempting to characterise cars without (a) knowing about manufacturers and (b) knowing about engines and transmissions. And then, when it turned out that the original classification system wasn't based on the deepest underlying facts, trying to keep it going regardless while shoehorning in new understanding.
Cross-fertility is, unfortunately, too simplistic. A great dane and a chihuahua are not cross-fertile, yet are the same species. A horse and a donkey are cross-fertile but are a different species.
There are lots of games that you can play to finesse these definitions of course, but still as an overarching definition for species it doesn't work, because the majority of organisms on the planet are not cross-fertile with anything and reproduce asexually.
Biology is complicated.
Chihuahua x Great Dane is possible but unwise due to physical issues such as size of the birth canal, the teat etc. Genetically they are compatible. Ass (Donkey) x Horse do NOT produce a fertile offspring (mule) - their offspring are infertile due to chromosomal number incompatibility (64 vs 62).
Oh, and the vast majority of organisms on the planet are bacteria and they DO reproduce 'sexually', in a fashion. They also reproduce asexually, and it's this bit that's taught up to O level biology - they leave out 'conjugation' until A level.
Boy is Biology complicated. As a Biologist I can attest that the species definition is losing its usefulness in Biology. Whether two species CAN interbreed is of much less import than DO they interbreed.
The species concept is a human one, not a natural one. It is used to make complicated populations more intelligible to mere humans but Nature is under no obligation to conform to the boxes we try and put it in.
There are two species of butterflies in Central America which border each other. When investigating how they maintain the border it was found that hybridisation did happen at the border but hybrids were not as successful as either parent species so died out. Nevertheless there was measurable gene flow between the two species. But to our eyes they still look like separate species.
In insects like butterflies speciation can occur when a female mistakenly or otherwise lays her eggs on a different host plant. The caterpillars eat that host and grow up to prefer to lay their eggs on it and mate with others who have also eaten that plant.
Phil Lord, apologies, a Great Dane vs Chihuahua is possible, they are dogs, they are "cross fertile" because they are no different in many ways than an Caucasian and an Afro-Caribbean. The issue is when you try to use a Great Dane dog vs Chihuahua bitch - and yes, it's been tried by mad people in the 'States. The other way around, a Great Dane bitch and Chihuahua dog would produce something, lord knows what.... I shudder to think, though the muppets that call their mongrels "Cockerpoos" and "Labradoodles" need correcting. It's a mongrel. It's not a new breed. Ask the Kennel Club, well try to....
The product of Horse & Donkey is a genetic dead end because Mules are usually generally sterile as they have 63 Chromosomes compared to the Horse having 64 and Donkey having 62. Not saying that they can't breed, but experience has shown it to be unlikely.
For any new "species" to be propagate, it must breed successfully within it's own "group".
Yes, biology is complicated. Put humans in abject squalor, with a 60" flat screen TV and the latest iPhone and see how well they breed....
Surely the increase in size is an adaptation rather than an example of evolution? One hears the words as interchangeable, but I am not sure that is the case. Recently heard a description of some sub-tropical animal in a UK zoo. which, they found, developed thicker fur as a response to the lower temperature described as "evolving" thicker fur, but it's surely just an adaptation.
Ingredients
4 Big Birds
8 Rashers of Bacon
500g Suet Pastry
Method
Place the plucked Big Birds in a roasting tray, and drape 2 rashers of bacon over each Big Bird
Roast for half an hour at Gas Mark 6, basting with the bacon fat.
After half an hour, wrap each Big Bird in suet pastry, and then steam for 4 hours.
I think you'll find that does a grand job of prooving the pudding!
(And don't forget a nice pint of ale to wash it down)
Classification of living things is very artificial and overlays the natural world rather like the rules of grammar attempt to order language. The best definition of a species that I know of is that it is that group of creatures defined as such by a competent taxonomist.
There are different operational definitions used in different sub-fields of biology. These days, however, having a common gene pool tends to be the fundamental definition.
If they're not interfertile, they're different species.
If the offspring are sterile, different species.
If the offspring are fertile but incapable of surviving for long in the wild, different species.
Even if none of the above are a problem, if they could successfully mate and have offspring that could continue to contribute to the same gene pool but choose not to mate, different species.
All of which gets complicated by ring species and clines, which can exist because gene pools are viscous.
Oh, and then there are rabbits in Australia. They've been artificially separated.. If you brought Australian rabbits back to Britain they're probably still the same species (don't do it the other way around because the Australians will get upset if you bring rabbits into the country) but eventually will no longer be.
All of the Panthera cats (lions, tigers, leopards, jaguars) can and will interbreed both in and out of captivity, though jaguars have a difficult time of stepping out with other cats due to the South Atlantic Ocean being in the way. Mostly it's due to male lions, who apparently will screw anything which holds still long enough. (Hmm. Sounds like some other males I know.) Male tigers are somewhat more circumspect, or at least less attractive to other kitties. Tigons (male tiger/female lion cross) and ligers (male lion/female tiger cross) are often fertile. Crosses with leopards and jaguars are much less so. Note that the biggest cats result from having a lion as the father; other kitties lack the gene complex that lionesses have which cuts back on the size, so ligers and litigons (tigons crossed with lions) tend to be really, really REALLY big cats. Here's a nice big house kitty: https://i.pinimg.com/474x/30/d9/25/30d925cf64948b1985e6ba75087d883f--ligers--years.jpg and here's daddy house kitty, son house kitty, and soon to be lunch: https://i.pinimg.com/originals/b9/f1/e2/b9f1e2ca81aeebf28229b7445f82c5de.jpg
See, they're nice friendly kitties, just the thing for inviting into the house.
I like wolves. They're less likely to roll over you and crush you by 'accident'.
Looks like the arrogant jumped-up scienticians lose again.
David Wolfe, is that you?
This only qualifies as "Evolution" by the thinnest and weakest definitions.
Hell, it barely qualifies as speciation(sp) and, as from the article itself, even that is debatable.
The Darwinian theory is a long way from modern theories on evolution! And going on the past, many of today's theories will be unrecognisable from those around in 50 years time...
Reading through the comments I find most of them rather clever or amusing...
I'm assuming there is specific individual(s) that aren't the followers of the evolution process, as most comments have at least one downvote, which on REG is rather unusual.
Wish you could find out who the voters are (like facebook)
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