From Brown University it seems we need a new variation on the popular bumper sticker:
Over 65 million years North American mammal evolution has tracked with climate change
Rise and fall of groups of fauna driven by temperature
PROVIDENCE, R.I. — History often seems to happen in waves – fashion and musical tastes turn over every decade and empires give way to new ones over centuries. A similar pattern characterizes the last 65 million years of natural history in North America, where a novel quantitative analysis has identified six distinct, consecutive waves of mammal species diversity, or “evolutionary faunas.” What force of history determined the destiny of these groupings? The numbers say it was typically climate change.
“Although we’ve always known in a general way that mammals respond to climatic change over time, there has been controversy as to whether this can be demonstrated in a quantitative fashion,” said Brown University evolutionary biology Professor Christine Janis. “We show that the rise and fall of these faunas is indeed correlated with climatic change – the rise or fall of global paleotemperatures – and also influenced by other more local perturbations such as immigration events.”
Specifically, of the six waves of species diversity that Janis and her Spanish collaborators describe online this week in the Proceedings of the National Academy of Sciences, four show statistically significant correlations with major changes in temperature. The two transitions that show a weaker but still apparent correlation with the pattern correspond to periods when mammals from other continents happened to invade in large numbers, said Janis, who is the paper’s senior and second author.
Previous studies of the potential connection between climate change and mammal species evolution have counted total species diversity in the fossil record over similar time periods. But in this analysis, led by postdoctoral scholar Borja Figueirido, the scientists asked whether there were any patterns within the species diversity that might be significant. They were guided by a similar methodology pioneered in a study of “evolutionary faunas” in marine invertebrates by Janis’ late husband Jack Sepkoski, who was a paleontologist at the University of Chicago.
What the authors found is six distinct and consecutive groupings of mammal species that shared a common rise, peak and decline in their numbers. For example, the “Paleocene fauna” had largely given way to the “early-middle Eocene fauna” by about 50 million years ago. Moreover, the authors found that these transfers of dominance correlated with temperature shifts, as reflected in data on past levels of atmospheric oxygen (determined from the isotopes in the fossilized remains of deep sea microorganisms).
By the numbers, the research showed correlations between species diversity and temperature change, but qualitatively, it also provided a narrative of how the traits of typical species within each wave made sense given the changes in vegetation that followed changes in climate. For example, after a warming episode about 20 million years in the early Miocene epoch, the dominant vegetation transitioned from woodland to a savannah-like grassland. It is no surprise, therefore, that many of the herbivores that comprised the accompanying “Miocene fauna” had high-crowned teeth that allowed them to eat the foods from those savannah sources.
To the extent that the study helps clarify scientists’ understanding of evolution amid climate changes, it does not do so to the extent that they can make specific predictions about the future, Janis said. But it seems all the clearer that climate change has repeatedly had meaningful effect over millions of years.
“Such perturbations, related to anthropogenic climatic change, are currently challenging the fauna of the world today, emphasizing the importance of the fossil record for our understanding of how past events affected the history of faunal diversification and extinction, and hence how future climactic changes may continue to influence life on earth,” the authors wrote in the paper.
In addition to Janis and Figueirido at Brown, the other authors are Juan Perez-Claros and Paul Palmqvist at the University of Malaga and Miguel De Renzi at the University of Valencia in Spain. Figueirido is also affiliated with Malaga.
Grants from the Fulbright program, the Bushnell Foundation (to Brown) and the Spanish Ministry of Science and Innovation funded the research.
It isn’t ‘evolution’ IF the organism already evolved to adapt to the change. Genes are the historical milestones we passed along the path of our survival. If we ever need tails we do not need to evolve to have them because we already have the genes for them.
Given how these eco-frauds are driving civilization backwards – well you just never know, we may need them again…
Until we recognize extreme natural events in the past, how can we understand and compare anthropogenic events?
Puzzle: In the context of comparing natural vs anthropogenic environmental events, what conditions are necessary to fossilize large dinosaur? Or to form a massive 1.4 sq mile dinosaur graveyard?
Consider real deep impacts.
Al Gored says:
December 27, 2011 at 1:21 pm
“The Spotted Owl, wolf and grizzly bear are the most lied about species in the West, and, coincidentally, the most important poster children for the eco-crisis industry.”
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Interesting that they are all predators, huh? The Spotted Owl story could fill a book. Much like the CFC scam the endangered finding was based on “lies and made up facts”. The old growth forest habitat protection effectively wiped out a huge segment of the logging industry and that’s what I found absolutely amazing. The reintroduction of the Grey Wolf has been problematic in a lot of areas. Ranchers are simply expected not to shoot wolves and allow them to prey on their stock. How “back to natural” is that? I don’t think domestic cattle are the wolf’s “natural prey.” We’ll have to wait and see what happens with the Dunes Sagebrush Lizard. Last July the EPA decided “more study was needed”, but this little lizard could quite possibly shut down a LOT of oil production. Seeing as they have survived alongside mankind’s petroleum production and cattle ranching in the Permian basin for the last 90 years I’m guessing they’re probably not about to go extinct due to habitat loss. Another little invention of the “environmental studies” biologist crowd is the concept of “local extinction”. So I suppose that means because I had magpies in my back yard the 10 years I lived here and I haven’t seen any the last few years they must have become “locally extinct.”
Dr Dave;
“Turns out the numbers of spotted owls continue to decline; not due to habitat loss but rather from competition from another species of owl.” Not even. The Barred Owl is actually a different, albeit more aggressive and adaptable, variety of the same species. They can and do interbreed.
As for the wolves, I’m all for them. The elk (and any grazers) strip forage, including tree shoots near streams resulting in the collapse of fish populations, down to the ground if left to breed unmolested. They need to be skittish and culled. The ranchers are compensated for the miniscule losses they incur; don’t worry about them.
Note the necessary kowtow to prevailing wisdom and funding criteria in the article:
“Such perturbations, related to anthropogenic climatic change, are currently challenging the fauna of the world today…”
Blech.
Paul Westhaver says:
December 27, 2011 at 11:47 am
That is an example of a reduction in the information content in the gene pool… that is natural selection. Not evolution……If we presume that evolution is a increase in the information in the genome of a species.
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Neither natural selection nor evolution implies anything about the increase or decrease in the total information in the genome of a species. It only advises about the results of CHANGES in the information which could and does include an increase, decrease or even the SAME amount of info.
For example, a SNP (Single-nucleotide polymorphism) is enough to potentially change one species into another and reflects absolutely no change in total informational content.
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In general, evolutionary changes can take as little as 25 generations as demonstrated for insects. The elapsed length of time this represents depends on generation time, eg less than one year in some tropical insects or roughly 500 years for humans.
Paul Westhaver
“Common descent is unsubstantiated theory”
??????????
ALERT TO ALL!!! This response is anti-evolutionary screed. A chance to sneak it into a climate blog.
First – understand what THEORY IS and ask yourself how such a thing which is nothing more than the verbalized substantiation of FACTS and then figure out how THAT can be unsubstantiated.
Second. Where have you been living?
Pat Moffitt
December 27, 2011 at 10:44 am
What a crock. “Previous studies of the potential connection between climate change and mammal species evolution have counted total species diversity in the fossil record over similar time periods.” There is absolutely no way to use the fossil record to compare the diversity at a species level to the present level of diversity with any type of confidence to make their next great leap in assumption about climate changes.
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I am pretty sure that this line is just the obligatory nod to the agenda. It seems every press release needs one.
Relating the criteria for defining species in the paleo record, with that used for extent organisms, is ridiculous. I am reminded by the old joke, “Its a species of teeth”.
The rest of the research appears to be on more solid ground. I will need to read the actual paper to be sure. But I think most students of evolution understand that environmental change is the number one driver of specification. Most of what is claimed is nothing new, even the five phases.
There is an interesting question here – What if anything does species diversity tell us?
Which came first, climate change or the evolution of certain mammals? With the exception of extreme natural events, it may be that the evolution of certain species led to climate change. In the relatively recent past, for example, man’s evolution, that of becoming a better hunter, led to extinctions of large mammals that subsequently led to changes in the environment that may have subsequently led to climate change.
Such perturbations, related to anthropogenic climatic change, are currently challenging the fauna of the world today
Right. They note several episodes of climate change over millions of years, yet this time the change just has to be anthropogenic. Sheesh. Pull the other one.
Dr. Dave says:
December 27, 2011 at 2:23 pm
Not so much that they are predators per se but their role as ‘apex predators’ or ‘ecological indicators’ theoretically means that if they are there the whole ecosystem is AOK.
Thus all three species are used as an excuse for other land management agendas. That is most clearly typified by the recently reintroduced wolf in the West. Predictably that population exploded and then spread far and wide, recently reaching California. As soon as one wandering wolf gets to a new area, the usual suspects are screaming that it is now ‘critical habitat,’ with all that goes with that.
They also keep moving the goal posts. When wolves were first reintroduced the target was 10 packs or about 300 total. Last time I checked they were insisting that about 3000 were necessary. And they kept winning court cases based on junk science by getting the ‘right’ judges, until recently.
Same but more localized story for grizzly bears and spooted owls.
Brian H says:
December 27, 2011 at 3:07 pm
Barred Owls are Spotted Owls are closely related but not the same species and I doubt very much if they would or could interbreed in the wild for many reasons. Now that their ranges overlap that is more possible but I still have not heard of that nor would i expect that. if you have a link to substantiate your claim that would be very much appreciated.
But, based on your simplistic and shallow comments on wolves and elk, I’m expecting that that was just something you heard about but some dubious source.
Pat Moffitt
December 27, 2011 at 3:51 pm
There is an interesting question here – What if anything does species diversity tell us?
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A diversity of species is an indication of extensive specialization as organisms evolve to fill smaller and smaller niches. It is a indicator of the final phase of the specification cycle preceding an extinction event. Notice that the time before all major extinction events are characterized by extensive specialization. Any significant environmental change (which is bound to happen) will cause the specialists to expire, while the generalist thrive and diversify. Its worth noting, that most of the extent organisms are the survivors of some pretty major environmental changes called the ice ages.
Pat Moffitt says:
December 27, 2011 at 3:51 pm
There is an interesting question here – What if anything does species diversity tell us?
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If you go with the normal assumptions, species diversity reflects the diversity of the micro/macro habitats present, the micro/macro habitat stability over time, and their productivity.
BioBob says:
“If you go with the normal assumptions, species diversity reflects the diversity of the micro/macro habitats present, the micro/macro habitat stability over time, and their productivity.”
I would agree- stability over time is the first thing that came to my mind. What is interesting however is there are more species in No America now than there were 300 years ago– so any modern reference at least for No America cannot be used to compare to diversity in the past. The mechanism by which diversity is achieved has been changed (importation, invasive what ever we want to call them) and so has its meaning making present comparisons to the past problematic.
There is also the productivity issue- depending on the metric -diversity does not always correlate with productivity. I have come to feel in the modern parlance species diversity is nothing more than a values judgement.
Tom G,
Adaptation is a laboratory demonstrable fact.
Selection (natural or artificially induced) is a laboratory demonstrable fact. (It is a reduction in the gene pool not an increase)
Mutation happens all the time, it is a fact.
Common descent is one of those concepts that alludes to a single spark of like and how it became the vast diversity we see on earth today. There is just no evidence for it.
Even Richard Dawkins says nobody knows how life started. Without that knowledge, it is impossible to be conclusive about the concept of common descent. If you know, please tells us. Before tossing insults, consult what I said and my references. They are mainstream.
I have a fish fossil in my china cabinet that they say is 250 million years old. It looks a lot like a fish I’d see today. This represents a challenge to common descent since it would seem that fish, our cousins, haven’t changed much in 250 million years yet humanity came from a small vole to what we are today. I am not discounting it… but I say it is in the realm of theory since we can’t provided evidence or reproduce it in a lab.
As far as evolution goes…. I am not quite certain as to what anyone means when they utter it.
Do they mean adaptation, or selection or mutation or common descent of a mishmash of imprecise unscientific blather and hand waving. I am quite happy with evolution of thinking and technological development and the like but as far and what happens in a petri dish I prefer more explicit terms.
BioBob,
I would categorize any CHANGE as a variation in information content +/_ (Second law of thermo). Also, the mitochondria DNA that we all share seems to have come from a single female at a homosapien “bottleneck” when the species was very nearly wiped out. The vast diversity in hominids was nearly completely lost. Now we have only one kind of M=DNA… all from “EVE”
again mainstream stuff..
http://en.wikipedia.org/wiki/Mitochondrial_Eve
It’s not only mammals.
Only twelve thousand years ago, all of western Washington was covered with a mile or more of ice. Georgia Strait, Puget Sound, the Strait of Juan de Fuca, and everything else was covered with ice.
Obviously, there were no salmon, an anadromous species. There was no spawning in appropriate locations in streams on the mainland, and there was, um, no man-made pollution. Still, the salmon survived, elsewhere.
As the glaciers melted, lakes formed, that, as they drained, formed much of the landform in the Puget lowlands. When the plug of ice in the Strait of Juan de Fuca melted, first at the bottom, as I understand it, the rush of water carved the valleys and even minor variations in the landscape we see now. The topsoil was nearly completely scoured away. Many present streams and rivers flow in relict glacier meltwater channels.
Only after this occurred were the salmon able to gain access to rivers in western Washington and Southern British Columbia.
I have faith in the ability of the salmon to adapt to changing conditions.
Desert Yote,
I read a great book call Grammatical Man by Jeremy Campbell. I did so before the human genome was decoded and prior to the now defunct claim that 98% of our DNA is junk.
The book suggested a neat thought I seem to recall.
The notion was that the information to enable adaptation may itself be encoded in our DNA, ie the rules for change and the means by which they occur, may be a manifestation of a deeper structure (plan) within the DNA. Our DNA may not be simply a biochemical template, but also a recursive algorithm and a database.
There seems to be evidence for this in the way that the bird flu virus mutates in a fairly regular and predictable way returning periodically to preexisting forms.
Paul W
I had my say. It needs no reiteration and you won’t sucker me into an evolution debate with someone who has an agenda. Your points are scattered and should be taken to a blog which deals with evolution vs anti-evolution.
Tom,
The trouble here is that you rightfully are concerned that should science be so thoroughly discredited because of the abuse of the scientific method in defense of AGW that a complete dismantling of science including but not excluded to the Theory of Evolution may be at risk.
That is you contribution. OK we get it.
Unfortunately it is not I who advances the AGW fake science and/or its connection with adaptation. That was done by the author.
How the mighty are falling….
RE: Paul Westhaver says:
December 27, 2011 at 6:24 pm
The shark is the most perfectly evolved fish. That’s why it hasn’t had to change. Meanwhile the misfit fish was driven to the mudflats, and evolved legs to escape the sharks.
The fittest may survive, but they don’t evolve. It is the misfits that change, because they absolutely have to.
In other words, sharks are still sharks because they are so fit. However we humans are the fish that didn’t fit in. Survival of the misfits!
This theory makes me feel a lot better about myself.
“… some really good evidence among the polyploids like salmon that we can see evolutionary changes in a matter of decades.”
Intriguing comment, Pat. Diploid rainbow, brown and steelhead, and triploid rainbow I know a bit about, having worked with them a while back. It was my understanding then and now that polyploidy implicitly confered infertile status throughout the range of salmonids, notwithstanding eg. Salmo salar. Enquiring minds need to know … 😎
Paul Westhaver
December 27, 2011 at 6:57 pm
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That the ability to “evolve” is an evolutionary trait is something I have felt to be true for a long time. One of the areas that I have studied the most, carnivore evolution, tends to lend credence to this notion. Its interesting to note that the same basic forms have appeared and disappeared many times.
But I also think that the ultimate adaptation is towards generalists who are able to modify their behaviors to meet the challenges of a changing environment. My favorite example of this is C. latrans. Static environments encourage specialization which produces a lot of diversity. But when the environment changes, and it always does, it will be the generalist that survive.
Pat Moffitt says:
December 27, 2011 at 6:18 pm
I would agree- stability over time is the first thing that came to my mind. What is interesting however is there are more species in No America now than there were 300 years ag
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it would truly be a very good trick if you could prove more species in N. Am 300 years ago considering that nobody knows exactly which species actually WERE here then or how many they totaled up to. LOL. We still do NOT know how many total species are here NOW for that matter, let alone prior to western civ’s impact. Species come and go and for the most part we barely notice.
Total productivity of a habitat may have little to do with species diversity.
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Paul Westhaver says:
December 27, 2011 at 6:33 pm
I would categorize any CHANGE as a variation in information content +/_ (Second law of thermo). Also, the mitochondria DNA that we all share seems to have come from a single female at a homosapien “bottleneck” when the species was very nearly wiped out. The vast diversity in hominids was nearly completely lost. Now we have only one kind of M=DNA… all from “EVE”
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Sorry Paul, but you insist “reduction in the information content in the gene pool… is natural selection.” and “evolution is a increase in the information in the genome of a species”. Both of these statements are simply incorrect without any kind of qualification. Simply WRONG ! Just learn from your errors and move along. Natural selection acts on the individual. Evolution is simply the aggregate result of natural selection. Both are concepts are indifferent to measures of increase or decrease of the species-genome itself.
I fail to see what the thermodynamics has to do with the “gene pool” and also fail to see what the junk-science-theories of Homo sapiens evolution has to do with the evolution of hominids in general.