Erratic Environment May Be Key to Human Evolution

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Image Credit: Wikipedia                                 Image Credit: Anne Knock

From Live Science:

At Olduvai Gorge, where excavations helped to confirm Africa was the cradle of humanity, scientists now find the landscape once fluctuated rapidly, likely guiding early human evolution.These findings suggest that key mental developments within the human lineage may have been linked with a highly variable environment, researchers added.

Scientists had long thought Africa went through a period of gradually increasing dryness — called the Great Drying — over 3 million years, or perhaps one big change in climate that favored the expansion of grasslands across the continent, influencing human evolution. However, the new research instead revealed “strong evidence for dramatic ecosystem changes across the African savanna, in which open grassland landscapes transitioned to closed forests over just hundreds to several thousands of years,” researcher Clayton Magill, a biogeochemist at Pennsylvania State University, told LiveScience.

The researchers discovered that Olduvai Gorge abruptly and routinely fluctuated between dry grasslands and damp forests about five or six times during a period of 200,000 years.

“I was surprised by the magnitude of changes and the rapid pace of the changes we found,” Freeman told LiveScience. “There was a complete restructuring of the ecosystem from grassland to forest and back again, at least based on how we interpret the data. I’ve worked on carbon isotopes my whole career, and I’ve never seen anything like this before.”

The research team’s statistical and mathematical models link the changes they see with other events at the time, such as alterations in the planet’s movement.

“The orbit of the Earth around the sun slowly changes with time,” Freeman said in statement. “These changes were tied to the local climate at Olduvai Gorge through changes in the monsoon system in Africa.”

Earth’s orbit around the sun can vary over time in a number of ways — for instance, Earth’s orbit around the sun can grow more or less circular over time, and Earth’s axis of spin relative to the sun’s equatorial plane can also tilt back and forth. This alters the amount of sunlight Earth receives, energy that drives Earth’s atmosphere. “Slight changes in the amount of sunshine changed the intensity of atmospheric circulation and the supply of water. The rain patterns that drive the plant patterns follow this monsoon circulation. We found a correlation between changes in the environment and planetary movement.”

The team also found links between changes at Olduvai Gorge and sea-surface temperatures in the tropics.

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Here’s the paper abstract

The role of savannas during the course of early human evolution has been debated for nearly a century, in part because of difficulties in characterizing local ecosystems from fossil and sediment records. Here, we present high-resolution lipid biomarker and isotopic signatures for organic matter preserved in lake sediments at Olduvai Gorge during a key juncture in human evolution about 2.0 Ma—the emergence and dispersal of Homo erectus (sensu lato). Using published data for modern plants and soils, we construct a framework for ecological interpretations of stable carbon-isotope compositions (expressed as δ13C values) of lipid biomarkers from ancient plants. Within this framework, δ13C values for sedimentary leaf lipids and total organic carbon from Olduvai Gorge indicate recurrent ecosystem variations, where open C4 grasslands abruptly transitioned to closed C3 forests within several hundreds to thousands of years. Carbon-isotopic signatures correlate most strongly with Earth’s orbital geometry (precession), and tropical sea-surface temperatures are significant secondary predictors in partial regression analyses. The scale and pace of repeated ecosystem variations at Olduvai Gorge contrast with long-held views of directional or stepwise aridification and grassland expansion in eastern Africa during the early Pleistocene and provide a local perspective on environmental hypotheses of human evolution.

Also, here’s the Supporting Information Appendix and an AGU ePoster from the same authors.

So research finds that climate change influences human development versus the inverse, Live Science appears to be an objective and informative information source, and Penn St. has honest and credible researchers, amazing stuff. I can end 2012 with a smile, I hope you all do so as well. :)    Just The Facts

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62 thoughts on “Erratic Environment May Be Key to Human Evolution

  1. So if the unstable climate in the distant past spurred human development, maybe the benign climate of the last 14,000 years has been the cause of the rapidly shrinking human brain. http://discovermagazine.com/2010/sep/25-modern-humans-smart-why-brain-shrinking
    If we don’t get some real climate chaneg soon, like the next ice age, we may all turn into muddle headed climate scientists and won’t have the common sense left to squeak through the next ice age like we did 140,000 years ago. http://www.scientificamerican.com/article.cfm?id=when-the-sea-saved-humanity

  2. “Slight changes in the amount of sunshine changed the intensity of atmospheric circulation and the supply of water. The rain patterns that drive the plant patterns follow this monsoon circulation. We found a correlation between changes in the environment and planetary movement.”

    We know the paper is fake just from this. The IPCC is clear. The sun has no effect on the planet and when it does its only from major changes like if it goes super nova.

  3. So even extreme, variable weather can be a positive thing from an evolutionary point of view. Too bad there’s no real evidence that CO2 actually causes extreme changes in the climate.

  4. “…Earth’s orbit around the sun can vary over time in a number of ways — for instance, Earth’s orbit around the sun can grow more or less circular over time, and Earth’s axis of spin relative to the sun’s equatorial plane can also tilt back and forth. This alters the amount of sunlight Earth receives, energy that drives Earth’s atmosphere. “Slight changes in the amount of sunshine changed the intensity of atmospheric circulation and the supply of water. The rain patterns that drive the plant patterns follow this monsoon circulation. We found a correlation between changes in the environment and planetary movement.”…”

    How could the AGW Warmists allow this heresy to pass through the editors of the Live Science?

  5. Kinda makes me wonder what we’d all look like now if for the last ~90,000 years we had always had central HVAC, mechanized food production, clean hot and cold water, TV, modern medicine, etc.? (Maybe like that movie about the future where everybody is just really really stupid?)

  6. This is not exactly ‘new’ research as far as I kknow. Neither does it explain why other creatures stayed relatively unchanged. Too little information, too much speculation.

    Do supercomputers navel gaze more robustly and with greater precision vis a vis the assumptive models fed into them than the lone scientists brain navel gazing over such matters?

  7. “An examination of the fossil record indicates that the key junctures in hominin evolution reported nowadays at 2.6, 1.8 and 1 Ma coincide with 400 kyr eccentricity maxima, which suggests that periods with enhanced speciation and extinction events coincided with periods of maximum climate variability on high moisture levels.”

    Trends, rhythms and events in Plio-Pleistocene African climate

    Quaternary Science Reviews 28 (2009) 399–411

  8. I don’t think people fully appreciate exactly how these evolutions occur. Many seem to believe, in my conversations with them, that changes in the environment result in behavioral changes as the primary adaptation mechanism. While that is true to some extent, I don’t believe that is the primary mode. I believe that in any given large geographic region there are several practices among the people there. At any given moment, the local environment either favors or disfavors certain practices. So lets say there are two tribes and one tribe has a traditional practice that works best with woodland environments and another works best with savannah environments or maybe it isn’t even that clear cut, say one practice is less impacted by change than the other even if only to a small degree. As climate and the surrounding environmental conditions change, the impact is unequal between these two populations. Maybe they both suffer but one suffers disproportionately more than the other or maybe. Eventually one comes to dominate the other and maybe the other completely disappears.

    We can see examples of this in our current situation. We have conditions that allow many different traditions to flourish. Veganism is one, in my opinion. That lifestyle requires year round access to a various vegetables that are not in season locally. It requires a huge infrastructure firing on all cylinders to support. In the case of a rapid change in climate to warming, that lifestyle thrives. In the opposite case, it would disappear. It takes a lot of energy to transport southern hemisphere veggies to Manitoba in winter.

    So we have a period when a lot of different traditions can flourish and then we have a period of rapid climate change that causes a selection of the ones best able to handle the new conditions. This provides periods of experimentation and diversity where new experiments in human traditions are tried followed by periods of stress where those traditions that are most fragile are weeded out. This line of thought is one of the reasons why I oppose such things as maintaining river flows at “average” levels even in times of drought. Those species that live there have evolved under conditions of optimum followed by stress. This causes as selection of adaptations that are best suited to the entire range of conditions. By maintaining flows at “average” conditions, we are preventing the selecting out of the weaker lines and the results could be catastrophic when conditions get so bad that we can not maintain them by artificial means any longer. We NEED to have these periods of renaissance and “dark ages” to allow new ideas to spring forth and then a period of stress to test them and allow those who have an advantage to survive. In humans, it means a period of comfort where all sorts of new ideas can be tried followed by a period of hardship where the ideas best suited to harsh conditions out-perform those less suited to conditions. People don’t necessarily “change” their behaviors over time so much as groups of people with different ideas might triumph in the next period of hardship and people with other behaviors tend to diminish.

  9. Toba (74kybp and similar pyroclastic events) punctuated things from time to time and contributed to basic point of the article.

  10. crosspatch says:
    December 26, 2012 at 11:27 pm

    That pretty much defines where we just might be. Then again, since this is an eccentricity minima, ~200ky from the next eccentricity maxima, we may just have to engineer our way around Sirocko, et al’s, (2005) assessment:

    ““Investigating the pro¬cesses that led to the end of the last interglacial period is relevant for understanding how our ongoing interglacial will end, which has been a matter of much debate…..”
    “The onset of the LEAP occurred within less than two decades, demonstrating the existence of a sharp threshold, which must be near 416 Wm2, which is the 65oN July insolation for 118 kyr BP (ref. 9). This value is only slightly below today’s value of 428 Wm2. Insolation will remain at this level slightly above the inception for the next 4,000 years before it then increases again.”

    Given the laten­cies for atmo­spheric heat reten­tion by CO2 lit­er­ally lit­tering the lit­er­ature, can you think of any­thing we might do to make it through the next 4,000 years “before it (insol­a­tion) then increases again”?

    Hmmmm, decisions decisions.….….….……

  11. From the paper…..
    The researchers discovered that Olduvai Gorge abruptly and routinely fluctuated between dry grasslands and damp forests about five or six times during a period of 200,000 years.
    ……
    Lends credence to Charles Hapgood’s theory of the poles wandering backwards and forwards over a short period every 35,000 years?

  12. It’s accepted that grasses evolved fire ( the spreading of naturally occuring fire) to help them compete with trees. This study (the rapid transitions from savanah to forest) indicates plants have evolved to manipulate the climate, e;g; through albedo, transpiration and rainfall runoff.

  13. Toba (74kybp and similar pyroclastic events) punctuated things from time to time

    I don’t completely disagree with this but events that cause significant dramatic changes are more frequent than Toba and other super volcanoes. For example, I think one of the things that greatly slowed the habitation of Western Europe (and possibly hastened the demise of the Neanderthal) by modern man was likely the eruption of Campi Flegrei about 40kya. The ash from this eruption seems to coincide with the transition from the middle to upper Paleolithic. Human habitation below the level of ash shows mostly Neanderthal technology. Habitation above, mostly modern. But this eruption practically sterilized a large swath of land that would have gone right across the migratory path of most of the herd animals of the time. It would have prevented human migration for a considerable time, too, until enough life returned to the region to sustain a trek on foot across it. In other words, this eruption would have cut off the path of animals migrating southward for the winter and they would have died attempting it. This would cut off or greatly diminished most of the food supply for the Neanderthal in what is now Central and Western Europe who relied on herds of animals that migrated considerable distances during the glacial. The Neanderthal in Eastern Europe would have been buried. A second smaller eruption about 12K years ago probably didn’t help matters much but much depends on which way the winds were blowing at the time. We know that ash from the first eruption can be found all the way to the outskirts of Moscow.

  14. It is long known fact that to enforce evolution on population, you need to split it up into many parts, apply stress, eliminate those parts of the population which failed to adapt, then repeat the process. That’s exactly what they discovered in Africa where many places were switching between habitable and unhabitable for human predecessors.
    Also, large portions of pre-human population getting eliminated by then was not such a big deal, they just silently died and left room for better adapted.
    Today humans won’t allow nature to perform any such inhumane experiments on them. That’s why climate change (or whatever you want to call it) is seen as such a threat.

  15. Why didn’t people move with the monsoon belt. The animals did. It seems to me that the movement of the monsoon belt is the fall back position when scientists are confronted with rapidly changing climate. How quickly did the monsoon belt change? It seemed to move fairly rapidly during the Holocene, on a number of occasions. In these kind of papers I always try and look at what is missing rather than what is said. Lots of stuff is left unsaid.

  16. Steven Mosher says:
    December 26, 2012 at 10:35 pm
    “they said the word models”

    Steven, Climate models are great tools to illustrate the past but lousy tools for prediction, can we agree on that? In the hands of a computer operator they can make for really realistically looking planets.

  17. Philip Bradley says:
    December 27, 2012 at 12:16 am
    “It’s accepted that grasses evolved fire ( the spreading of naturally occuring fire) to help them compete with trees. This study (the rapid transitions from savanah to forest) indicates plants have evolved to manipulate the climate, e;g; through albedo, transpiration and rainfall runoff.”

    Very logical! Co-evolution! Of course!

  18. Mike M says:
    December 26, 2012 at 10:41 pm

    Kinda makes me wonder what we’d all look like now if for the last ~90,000 years we had always had central HVAC, mechanized food production, clean hot and cold water, TV, modern medicine, etc.? (Maybe like that movie about the future where everybody is just really really stupid?)

    Think “Wall-E”…

  19. mogamboguru says:
    December 27, 2012 at 5:09 am
    Mike M says:
    December 26, 2012 at 10:41 pm
    Kinda makes me wonder what we’d all look like now if for the last ~90,000 years we had always had central HVAC, mechanized food production, clean hot and cold water, TV, modern medicine, etc.? (Maybe like that movie about the future where everybody is just really really stupid?)
    Think “Wall-E”…
    ====================================
    Less like “Wall-E”, more like Kent Dorfman

  20. I think I prefer to get my human origins explanations from anthropologists and not climate scientists. (Do we need another myth about climate science).

    To correct some of the misinformation in this article …

    About 8 million years ago, the climate started drying out for whatever reason, At this time C4 grass pollen starts to become more common in sedimentary deposits while before this time, there was almost none. These grasses evolved 24 million years ago but they did not become prevalent until dryer conditions and less rainfall overall started to give them an advantage over C3 bushes and trees.

    By 6 million years ago, the first savannas developed as the climate continued drying out. Before this time, the entire planet was one big forest, There was no grasslands or savanna or deserts. It was planet of the Apes and there was 50 different species.

    As the Sahara started to develop grassland at the 6 million year timeline, our story begins with the development of up-right walking.

    A BBC documentary called the Origins of Us is probably the best explanation about how climate change and our physiological developments led to us. Several new things you would not have heard of in this documentary.

    Search “bbc origins of us youtube” on google.

  21. William McClenney says:

    December 26, 2012 at 10:52 pm

    “An examination of the fossil record indicates that the key junctures in hominin evolution reported nowadays at 2.6, 1.8 and 1 Ma coincide with 400 kyr eccentricity maxima, which suggests that periods with enhanced speciation and extinction events coincided with periods of maximum climate variability on high moisture levels.”

    Trends, rhythms and events in Plio-Pleistocene African climate

    Quaternary Science Reviews 28 (2009) 399–411
    =======

    Remarkable that the 400kyr cycle should exert some sort of tidal influence on our DNA without exhibiting any statistical power in the ice or sediment cores.

  22. This sedimentary evidence for rapid and multiple transitions forest-grassland is interesting and important, though of course hardly new as several including William McClenney have pointed out. It introduces a set of important players like a Quentin Tarantino movie. CO2 in air was decreasing toward a life-threatening level. In response, C4 grasses evolved. Their arrival destabilised / de-equilibrated the climate-ecosystem phase space with the resulting flicker between two quasi-stable attractors of grassland and forest.

    It is well known from Vostok and other ice-core records that “glacials” are not very stable and are punctuated by many abortive interglacials and even “micro-interglacials” of century scale duration. Thus human evolution has taken place during the predominantly glacial pleistocene characterised by acute climate fluctuation and instability. An evolutionary advantage in intelligent adaptation to climate change clearly existed (and still does today).

    With the overall focus of human origin correctly on Africa, it is sometimes forgotten that hominids temporarily disapppeared from Africa. OVer the last million years or so there have been about 5 major “out of Africa” radiations. One of these established an enduring population of hominids in Asia. It is just as well, since homosubsequently went extinct in Africa. Africa was later repopulated with hominids from Asia. The genetic evidence for this is presented in “The Ancestor’s Tale” by Richard Dawkins.

    Its clear why the climate and media elite dont want climate change. They feel threatened by intelligence.

  23. It may be “pure unsubstantiated speculation presented as science” (arthur4563), yet is it one of the few such papers I have seen where believers in evolution and Darwin actually included humans and did not try to stop every bit of the evolution on the planet. Current belief seems to be that Darwin was right until “save the earth Greens” realized that Darwin was SO wrong and that nothing ever should change. And it wouldn’t if we just would stop burning fossil fuels and using up resources. No extinct species, all happily-ever-after. I was very shocked that someone actually thought humans were part of Darwin and the change is good, even though we should stop it to save the planet.

  24. Desmond Morris first noted the thing that sets us apart in his book ‘The Naked Ape’ but made little of it. The human female is permanently receptive to the male, does not advertise when she comes in to season and can breed at any time of the year. This makes it almost impossible to be a human alpha male with a harem, you’d be on your knees, it completely restructures the social groupings.
    Homo errectus survived well over a million years of climate change but the last ice age forced him to evolve or die. You have to ask yourself, what did H.heidelbergensis have that he did not? Could it simply be that without a constraining alpha male everyone got destressed, had a lot more free time and the full potential of the gene pool for evolution was opened up by pair bonding?

  25. Reality check says:
    December 27, 2012 at 7:38 am
    “Current belief seems to be that Darwin was right until “save the earth Greens” realized that Darwin was SO wrong and that nothing ever should change. ”

    Darwin actually thought that evolutionary change happens gradually; his ally Huxley had a different opinion. Today we know Huxley was right and that evolution happens by punctuated equilibrium.

    The Greens still believe that Darwin was right and usually say that the rate of change we are producing overwhelms evolutionary processes. I don’t think it would be possible to explain punctuated equilibrium to them as it’s a little complicated.

  26. Kasuha says:
    December 27, 2012 at 1:47 am
    It is long known fact that to enforce evolution on population, you need to split it up into many parts, apply stress, eliminate those parts of the population which failed to adapt, then repeat the process. That’s exactly what they discovered in Africa where many places were switching between habitable and unhabitable for human predecessors.
    Also, large portions of pre-human population getting eliminated by then was not such a big deal, they just silently died and left room for better adapted.
    Today humans won’t allow nature to perform any such inhumane experiments on them. That’s why climate change (or whatever you want to call it) is seen as such a threat.

    For better or worse, we now adapt socially, that is, our societies adapt.

  27. @DirkH, reality check

    Indeed the greens in question would do well to read some Steven J Gould (punctuated equilibrium).

  28. @Gail Combs

    Good one by Vuk, looks like he flipped it left-right for the hockey-stick effect; or maybe I did, I dont remember

  29. These grasses evolved 24 million years ago but they did not become prevalent until dryer conditions and less rainfall overall started to give them an advantage over C3 bushes and trees.

    I think reduction in atmospheric CO2 also give the grasses advantage over the trees. I will try to find it but I believe there is correlation between a reduction in atmospheric CO2 and the rise of the C4 plants. Along with the rise of the grasses we see the demise of many other plants. For example the Araucariaceae family of trees sees a dying off that is just about coincident with the rise of the grasses. Today there are only a few species of this family of tree (Norfolk Island Pine, and “Monkey Puzzle Tree” being a few popular examples) left around the world. The demise of these trees probably has more to do with atmospheric reduction of CO2 than any change in moisture. We still have places in the world where it is quite wet, but these species which once dominated the entire planet (the huge logs at Petrified Forest are examples of this family) are now nearly gone.

  30. Crosspatch –
    Thanks for your excellent summary. Your comments about artificially keeping the river flowing especially made me think – first, I remembered a big piece of Texas news from the early 2000’s. The Rio Grande failed to flow all the way to the Gulf of Mexico, mostly from overuse. There were some ridiculous attempts to dig a trench some hundreds of yards (or whatever it was) out to the sea, but that would have just let the sea flow into the river, instead of the digger’s intent…
    Also, I recently saw this picture (link goes to PB):

    http://tinyurl.com/c2gjkuw

    Definitely one of the things that our smarts and technology has given us is the ability to overcome natural shortcomings – for example, I wear contact lenses for myopia – Anthony Watts uses a hearing aid – etc. It would be pretty hard for us to function, normally, or at all, without these things, and most likely the faulty genes or behavior (staring at lasers/too much loud music) would be weeded out, evolutionarily speaking.

    Fortunately, this idea is not lost on low levels of education, and certainly comes to mind in most high school students. More commonly discussed are popular, “interesting” topics, like are we evolving away our little toe, but the overall message is there – we have, and have been practicing for some time, the ability to overcome natural selection.

    Perhaps there is an ultimate control factor kicking in, and as others above have mentioned, perhaps we are evolving smaller brains, to ultimately become dumber, and “return to nature”. Time will tell, and the only certainty is that if we don’t get off earth at some point in the far distant future, we are destined to disappear. But this is far enough off to not be a concern for most likely the next several centuries, at least.

    So we see it is easy to tell where humans get their tremendous ego that leads to these massive green schemes. Even a teenager understands that we have conquered nature when it comes to ourselves. We have a demonstrated ability to decide whether whole species and ecosystems live or die. I have said before that the greatest survival trait an animal can possess or evolve in the modern world is to look cute, or otherwise be attractive to humans. So while we can control ourselves, we can control life all around us, it is an easy mental step to say we can control inanimate natural processes as well. And with civil engineering and landscaping and agricultural methods, to some extent we believe we really can.

    The fallacy, of course, is that none of this is true, and that we as humans maintain the illusion of control by implementing artificial controls, just like in your river scenario. Nature holds all the trump cards, and will ALWAYS have the ability to go farther than we can master. In practice this is simple escalation – it rains, so we dig a drainage pond. It doesn’t rain, so we irrigate. It floods, so we build dykes. It droughts, so we dam rivers for on-demand water. And so-on and so-forth. But we can’t stop an earthquake. We can’t control a volcano. We can’t make it rain, or stop raining – we can’t affect the weather/climate. So we are trying to. And some prefer the illusion of control, and the delusion that in this case we have it, with CO2; to the hard reality that we do not.

    So an argument like Monckton’s becomes practical not just in the economic sense that he espouses. (I am talking about the argument that we should hold off on climate change measures for now, and react/adapt instead of attempting to prevent/control.) THIS is our true advantage. THIS is what we should be capitalizing on, instead of struggling so hard against it. We have evolved this tremendous intelligence that gives us the ability to adapt, to react to changes in our surroundings, to survive. Stop trying to control the world, and instead adapt ourselves to where the world is going.

    Stop trying to control things, and instead adapt to where things are going.

    Unfortunately, going from the first half of that sentence to the second half is the most severe mental hurdle many people will ever face, and the implications of it may been seen in every aspect of human life (e.g. controlling economic markets vs. letting them go, parents attempting to enforce decades-old ideas on their children, elderly refusing to adopt new technologies, drug users of all kinds manipulating their emotions instead of dealing with them).

    Forced progressivism is equally as bad and wrong as forced regressivism or artificial controls maintaining the status quo. Time is passing, life is happening and going by, whether we want it to or not. Why should we waste ourselves swimming upstream?

  31. It would be pretty hard for us to function, normally, or at all, without these things, and most likely the faulty genes or behavior (staring at lasers/too much loud music) would be weeded out, evolutionarily speaking.

    Well, I believe things like myopia were what led to division of labor. Take a time many thousands of years ago when all males were hunters/warriors. Some males would have better eyesight and make better hunters than others. Those with poor eyesight probably weren’t able to feed as large a family or maybe fell prey to a wild animal or stepped on a snake or something. This tended to reduce the number of men with poor eyesight. Then somewhere along the line, someone realized that the guy with poor eyesight who wasn’t much of a hunter made really good spear points or was good at making fish traps or other fine work that could be done close up. We then start to see a division of labor where someone makes fish traps in exchange for fish or spear points in exchange for meat. So once we have people specializing in various things, we develop a situation where the results of the hunt are brought back and shared among the community because everyone in that community played some supporting role in obtaining it. Those who did not pull their weight or were some sort of burden to the community (say, by stealing) were exiled to the wilderness alone where they probably didn’t survive long, particularly once winter came in the temperate regions.

    Someone who has some handicap that makes them less able to survive on their own might actively seek out some other skill that makes them worth having around. And some of these traits might be hereditary so that the skill is passed from father to son because the father’s poor eyesight was passed from father to son and the father is passing along a worthwhile skill. We also see that the way labor was often divided between men and women, myopia would be less of a handicap for their sort of work and we see that generally more women than men are nearsighted though in today’s world we see much more nearsightedness than we did before spectacles were invented because before that time, nearsighted individuals might not have been able to provide quite as much of their own food or maybe were more likely to suffer accidents. I would imagine that drafting of men for an army in the 1600’s would have brought out people with a wide variety of different degrees of eyesight. I would also be willing to bet that warrior clans were those where good eyesight ran in the family. Good eyesight is “expensive” to produce genetically and eyes tend to be only as good as required. If we suddenly lost the ability to make corrective lenses, we would probably see the population decline but the overall average eyesight would improve.

  32. phlogiston says:
    December 27, 2012 at 11:31 am
    “@DirkH, reality check
    Indeed the greens in question would do well to read some Steven J Gould (punctuated equilibrium).”

    It can be observed in genetic algorithms. I often have weeks with no process, then a cluster of days with successive improvements. I observed this in logic optimization evolutions as well as in trading strategy optimizations. In both cases, I use analogons to s3xual reproduction (crossovers, introns).

  33. I have had a question for some about why the North Pole is generally warmer than the South Pole. Could someone tell me where my understanding is incorrect or incomplete?

    In simple terms: I can see one major reason, but am not sure. But first, there are two major phenomena which cause the climate of the poles. Nearness to the sun and axis of rotation. During the southern hemisphere’s summer, the earth is closer to the sun. Of course the tilt of the earth has a far greater affect on temperatures in that hemisphere than does the distance. One would think it logical for the southern hemisphere to have a warmer summer than the Northern Hemisphere. Conversely, the South Pole during winter is both tilted away from the sun while the earth is farther from the sun during its winter so it should have colder winters than the Northern Hemisphere.

    All else being equal (and it isn’t), the average energy in both hemispheres should be the same, however. I’ve always thought that since the North Pole is all water and that water circulates, there would be more warmth there than in the South Pole region which is a giant land mass.

    My conclusions:

    1) North and South Hemispheres get the same energy from the sun over a calendar year.
    2) South Hemisphere has more extremes (more energy in summer, less energy in winter than North hemisphere.
    3) Land Mass in South Pole has the greatest affect on climate there, being an island which is less affected by direct contact with water circulation.

    Is it much more complex than this?

  34. Heh, now I wonder if those animal paintings on the walls of caves were an eye test for hunters. The idea being someone had to stand some distance away while someone pointed to different animals and the prospective hunter had to be able to discern which animal was which. Those who could do so accurately were accepted to become hunters and those who didn’t became weavers or some other job.

  35. 2kevin
    December 26, 2012 at 10:42 pm
    ###

    Climate variability has been one of the strongest factors in Carnivore evolution.

  36. DesertYote says:
    December 27, 2012 at 2:22 pm

    Climate variability has been one of the strongest factors in Carnivore evolution.

    Close, however the intent of your thought is better expressed …

    Prey variability has been one of the strongest factors in Carnivore evolution.

    —–

    I caution ALL readers (and writers) to remember that – unless one accepts “Evolution” as a forwardly cognizant Intelligent Designer who (simultaneously!) observes things as they actually are in the current world, correctly anticipates the future world and the future environment and “plans” genetic improvements in tens of millions of species FOR the specific and unique future that the Intelligent Designer has projected hundreds and millions of years into the future – one can only describe “evolution” as “repeated accidental and random genetic mutations that don’t immediately kill its victim nor the children of its victim

    “Evolution” – as it is accepted in today’s “science” – cannot predict, adapt,defend, change, nor prevent changes in any single generations Only an Intelligent Designer can act deliberately and with forethought.

  37. It is impossible to take these people seriously. They use “transition” as a verb.

    “in which open grassland landscapes transitioned to closed forests”

  38. Difference in temperature of the poles: Two things: altitude and proximity to open water. The South Pole is at 10,000 feet altitude and is a long way from open water. What is the temperature 10,000 feet above the North Pole?

  39. RACookPE1978 says:
    December 27, 2012 at 2:44 pm
    ““Evolution” – as it is accepted in today’s “science” – cannot predict, adapt,defend, change, nor prevent changes in any single generations Only an Intelligent Designer can act deliberately and with forethought.”

    You can direct an evolution by designing the evaluation function. I’m not very good at that. A creator god would probably be more capable.

  40. The author Michael Crichton proposed that development occurs best in the border region between stability and chaos.
    Too much stability and there is no impetus for growth, too much chaos and there is no stable ground on which to build growth.

  41. “This is not exactly ‘new’ research …”

    I’m not even sure if it was exactly ‘new’ research twenty years ago when I first remember reading about it as an undergrad. Then again, this was in a class where the prof was fond of saying that the discovery of new species was often more closely correlated to researchers’ needs for funding than the appearance of new information. No reason the same doesn’t apply to new theories as well?

  42. RACookPE1978
    December 27, 2012 at 2:44 pm
    ###

    Yes, prey variability has been an important result of climate variability that has driven Carnivore evolution, but habitat variability has also played a significant role. Without going into much detail, carnivores can be classed as hyper-carnivores, meso-carnivores, or hypo-carnivores. Hyper-carnivory tends to be more vulnerable to changes in prey. But one of the best examples of a hyper-carnivore extinction, the Dire Wolf, not only succumbed to reduction of its prey, but to the elimination of its habitat. It was a grassland animal, ill suited for life in the forest that replaced the grasslands. The Grey Wolf, who has its own climate change story, was well suited to life in the forest and more importantly to life on the prairie as well. As a side note, it is also less hyper-carnivorous, so far less dependent on prey variability then poor C. dirus.

    BTW, one carnivore line that has not changed much, a dedicated meso, is the one that is currently represented by my namesake, the coyote, and the golden jackal. But in general, the evolution of meso-carnivores is tightly linked to climate effects not related to prey directly.

    One of the big drivers has been the opening and closing of the land route between Asia and North America. The ancestor to the large wolf-like canines probably first showed up in India, spread about Asia, when the last glaciation stranded a population in the Bearingia refugia. This population became old C.lupus. Another land bridge story is the Leopard, who’s ancestors are from North America. This lineage also led to the Jaguar before it extended its range to South America. It is sill found in Arizona.

    As for the rest of your comment, I’ll start with a disclaimer. I am a Christian who believes in a G*D Who has a Plan, a G*D Who uses Processes. Evolution is a process. I am also an amateur mathematician who loves playing with chaotic system. I see no contradiction, and never have.

    First, I see evolution in terms of trajectories. I hate using the term superior. I read an interesting statement once. “Every organism is perfectly adapted to its environment.” It’s true that evolution tends toward the more complex, but examples of the opposite are abundant. Is an placoderm inferior to a teleost? Who can judge? Not I. As for trajectories, carnivore evolution is filled with examples of lineages headed to a hyper-carnivorous condition, then back to a meso. Trajectory changes.

    Second, evolution is not really about survival of the fittest, as much as it is about the ability of a population to produce offspring who live long enough to reproduce. Individuals don’t evolve, populations do. I hope you understand the significance of that. The simple random mutation model sort of falls a little flat.

    In addition to enhancement to the ability to adapt, like C. latrans. one of classes of traits that organisms have evolved, are enhancements to the ability to evolve. I have kept aquarium fish for close to 40 years. I notice a very strange phenomena while breeding cichlids (which, for the record are superior!). The spawn from a pair that had just reached maturity would exhibit a great deal of variability. Subsequent breeding would produce successively less variability until the parents fourth or fifth spawning. In the wild, cichlids don’t normally successfully breed until they are a few years old.

    Boy, I have written too much already. Its hard to serialize out the thoughts I am trying to express. I’ll try to sum things up. The process of evolution is far more complicated then the simple story that is taught in school more as a vehicle to slam Christianity, then to teach actual science. Its more then just chance random events, ore else the same forms would not keep showing up in different lineages.

  43. DesertYote says:
    December 27, 2012 at 11:14 pm
    “I am a Christian who believes in a G*D Who has a Plan, a G*D Who uses Processes. Evolution is a process. I am also an amateur mathematician who loves playing with chaotic system. I see no contradiction, and never have.”

    Very logical. See also universe as an evolutionary process (Big Bang theory was first introduced by a cleric and rejected by mainstream cosmologists – now the mainstream cosmologists themselves try to create theories that explain an evolution of particles and the natural laws that we observe now from a quite different starting condition; and see also the Brahma Egg creation myth of the Hindus)

    The rabid atheism of Dakins looks more and more like a pretty ignorant position to me; a “lifeist” (Life-ism – an ideology that holds that life is special and superior to non-life… Dawkins can only explain what happened AFTER life suddenly came into existence – not HOW it came into existence or what happened before that moment. My non-living individuals in my genetic algorithms would object.)

  44. Terrible piece of speculation, it even implies that we humans can adapt to a changing climate, a thing which is unprecedented in human history, according to climatology.
    sarc off.
    I agree the biggest obstacle to clear reasoning is our conceit. We control the weather, really we do, I insist its true. May storms strike if you doubt……..
    Seriously I keep wondering if climatology is a mental disorder spawned by urban living and lack of physical experience with weather.
    Will it go away when the sufferers are evicted from their parents basements? Released from their govt offices?

  45. Kasuha says: December 27, 2012 at 1:47 am

    That’s why climate change (or whatever you want to call it) is seen as such a threat.
    =============================
    What climate change, pray tell?

  46. @john: It seems likely climate change belief is a form of memory loss. The sufferer cannot remember what the weather was like over 10 minutes ago and thus believes any made up data he is presented with. Every storm seems the biggest and most damaging because they cannot remember any other storms. It’s sad.

  47. The main question here is – why did genus Homo (Habilus say) evolve from the Australopithecus genus? The “climate” answer hardly satisfies this question. If the periodic ice ages, which started about 3 million years ago, caused such rapidly changing environments that higher intelligence was required to adapt, then why did not other animals evolve similarly?

    Of course the answer involves other factors. These hominids apparently discovered how to use stone tools to access the meat in carcasses, which allowed them to scavenge, hunt, or steal meat off other predators. My favourite theory is the “stealing” strategy, as other predators and scavengers already abounded. Its unlikely that an Australopithicene could ambush prey, or run them down, or beat a hyena to left-over scraps. Stealing meat off predators obviously encourages higher intelligence, cooperative behaviour, and language.

    Climate, which always changed slowly when measured against the lifespans of individual hominids, would simply have gradually moved ranges backwards and forwards, at a rate that the hominids could easily adapt to.

  48. “May you live in interesting times.” Frequent severe bottlenecks are indeed the ideal stimulus to rapid evolution. Long boring periods of salubrious climate, not so much. Punk Eek ain’t fun to experience.

  49. DirkH says:
    December 27, 2012 at 1:15 pm
    phlogiston says:
    December 27, 2012 at 11:31 am
    “@DirkH, reality check
    Indeed the greens in question would do well to read some Steven J Gould (punctuated equilibrium).”

    It can be observed in genetic algorithms. I often have weeks with no process, then a cluster of days with successive improvements. I observed this in logic optimization evolutions as well as in trading strategy optimizations. In both cases, I use analogons to s3xual reproduction (crossovers, introns).

    Interesting result, it makes sense. Genetic evolution can only work on what is there – people sometimes ascribe (wrongly) a kind of omnipotence to genetic evolution, i.e. “anything that can be an advantage will evolve”. This is not the case – evolution is only possible from what is already there and by pathways that are possible. No organism (excluding the bacterial flagellum) has ever evolved a wheel, for example, despite the major advantages for travel that it provides. The requirements for blood supply and innervation, and the absence of any biological equivalent of “bluetooth”, make it impossible, despite its advantages.

    Its worth noting that even in periods of apparent evolutionary quiescence (i.e. absence of major extinction events) if you look closely you find genetic evolution is still very busy. For instance the large cold-water king crabs, weighing up to 20 pounds (9 kg), evolved quite recently and very fast from hermit crabs – thats why they are still a little lopsided (asymmetric) even though they dont need to be since they no longer have to squeeze into a snail shell. Old habits die hard. Its an example of “carcination”, i.e. that “crab”-like animals have evolved 5-6 times from several starting points (in the sea, everyone wants to be a crab).

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