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They cannot carry out photosynthesis
To my knowledge, nobody has ever invoked a climate change hypothesis for the mass extinction of South American mammals when the land bridge formed that , even though the formation of that land bridge probably triggered the current ice age and the North American invasions of South America. Most South American mammal species quickly went extinct when that had survived many millions of years of intercontinental invasions. It was a purely Darwinian event in which animals with greater carrying capacities prevailed. There was no big picture awareness of events by the invaders or invaded, just as there had never been during life’s history on Earth. They all just tried to survive, and previously isolated South American mammals quickly lost the game. The survivors were able to live in niches that no North American animals did, such as .
This protist is both an autotroph, meaning it can carry out photosynthesis and make its own food like plants, as well as a heteroptoph, meaning it can also capture and ingest its food. When acting as a autotroph, the Euglena utilizes its chloroplasts (which gives it the green colour) to produce sugars by photosynthesis, when acting as a heterotroph, the Euglena surrounds the particle of food and consumes it by phagocytosis, or in other words, engulfing the food through its cell membrane.
Some bacteria can carry out rudimentary photosynthesis, ..
The relatively gentle river valleys of Mesopotamia and Egypt saw long, slow declines in their environments, but when civilization came to the more mountainous periphery of the Mediterranean Sea, environmental damage came much faster and more dramatically, particularly as the Stone Age gave way to the Bronze and Iron ages. Before civilization arrived, the Mediterranean’s periphery was heavily forested and, as with Lebanon, cedars were plentiful. Today, Lebanon has several small groves of cedar, as a kind of museum of former greatness, and efforts to are ongoing. The about , and island-dwarfed hippos and elephants went extinct soon after humans arrived. Any land that can support hippos is blessed with an abundance of water, and islands such as Crete and Cyprus were blanketed with verdant forests before the rise of civilization.
Sumerian city-states engaged in irrigation, which raised the water-tables. When the water table in those waterlogged soils reached the surface, the soils turned white with salt, especially with the high evaporation of those hot lands, and it would no longer support crops. The only solution was to stop irrigating and let the land go fallow as the water table fell, but the population pressures did not allow for it, so the process inexorably created saline soils, silt-filled canals due to upland deforestation, and today those Sumerian cities are all buried in silt in a desert. Eridu was a seashore city, and today its ruins lie more than 200 kilometers inland. But before silt and salt wrecked that civilization, many seminal inventions appeared. The appeared in . Gravity took a ship downstream, and wind power helped it move back upstream.
as they contain chloroplasts an can carry out photosynthesis.
But the branch of the that readers might find most interesting led to humans. Humans are in the phylum, and the last common ancestor that founded the Chordata phylum is still a mystery and understandably a source of controversy. Was our ancestor a ? A ? Peter Ward made the case, as have others for a long time, that it was the sea squirt, also called a tunicate, which in its larval stage resembles a fish. The nerve cord in most bilaterally symmetric animals runs below the belly, not above it, and a sea squirt that never grew up may have been our direct ancestor. Adult tunicates are also highly adapted to extracting oxygen from water, even too much so, with only about 10% of today’s available oxygen extracted in tunicate respiration. It may mean that tunicates adapted to low oxygen conditions early on. Ward’s respiration hypothesis, which makes the case that adapting to low oxygen conditions was an evolutionary spur for animals, will repeatedly reappear in this essay, as will . Ward’s hypothesis may be proven wrong or will not have the key influence that he attributes to it, but it also has plenty going for it. The idea that fluctuating oxygen levels impacted animal evolution has been gaining support in recent years, particularly in light of recent reconstructions of oxygen levels in the eon of complex life, called and , which have yielded broadly similar results, but their variances mean that much more work needs to be performed before on the can be done, if it ever can be. Ward’s basic hypotheses is that when oxygen levels are high, ecosystems are diverse and life is an easy proposition; when oxygen levels are low, animals adapted to high oxygen levels go extinct and the survivors are adapted to low oxygen with body plan changes, and their adaptations helped them dominate after the extinctions. The has a pretty wide range of potential error, particularly in the early years, and it also tracked atmospheric carbon dioxide levels. The challenges to the validity of a model based on data with such a wide range of error are understandable. But some broad trends are unmistakable, as it is with other models, some of which are generally declining carbon dioxide levels, some huge oxygen spikes, and the generally relationship between oxygen and carbon dioxide levels, which a geochemist would expect. The high carbon dioxide level during the Cambrian, of at least 4,000 PPM (the "RCO2" in the below graphic is a ratio of the calculated CO2 levels to today's levels), is what scientists think made the times so hot. (Permission: Peter Ward, June 2014)
Also, just as no fundamentally new body plans appeared after the Cambrian Explosion, modern ecosystems seem constrained by body size. Body sizes have similar “slots,” and body sizes outside of those slots are relatively rare. However, successful innovation usually happens at the fringes. The fringes are where survival is marginal and innovations carry a high risk/reward ratio. Most innovations fail, but a successful one can become universally dominant, such as those biological innovations that are considered to have happened only . There have been countless failed biological innovations during life’s history on Earth, many of which might have seemed brilliant but did not survive the rigors of living.
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Amoeba can be harmful or helpful to man-kind and other living things
Chimpanzee social organization has male and female hierarchies, and societies of up to 120 members. Fruit trees form the center of a chimp society’s territory, where females forage with their offspring and males form foraging parties that patrol the territorial perimeter. Chimps have foraging parties of less than 10 members, it ranges between two and nine, and party size fluctuates rapidly. That is because chimps have to walk kilometers between food sources each day, primarily fruit trees, and varying harvests cannot reliably support larger groups. In general, the larger a territory, the faster chimps breed, as they have more available energy.
"Amoeba may offer key clue to photosynthetic ..
Bonobos are the only non-human African great ape exception to infanticide, and are also the only great ape species that does not sexually coerce females, humans included. The reason seems to be the social organization that arose from a plentiful food supply that allowed for larger groups in which females males actively reduced male violence. Many behaviors within and between bonobo bands are unknown with chimps. A male bonobo will remain with his mother for her entire life, and male bonobos do not vie for dominance. Instead, bonobos have a sexuality that no other animal on Earth has remotely approached. They settle nearly everything with sex. Female on female is common, particularly when bands meet, but , with the sole exception of mothers and sons, as the aversion to inbreeding is rooted deeply in animals and is also responsible for the human incest taboo. Bonobo societies are and seem to live by the slogan, “Make love, not war.” But it started with their economy, when their primary and dominant competitor moved away. In recent studies, the only bonobo sexual coercive acts observed are females abusing males, which is also rare. A likely influence on ending infanticide is that female bonobos, like humans, conceal their ovulation, so males are not cued to compete to be the father. Also, since virtually all bonobos have sex all the time, there is no way for bonobos to determine paternity.
How does amoeba Carrie photosynthesis?
Were the dramatic changes in a result of cooked food, or was Turkana Boy as his species became hunters instead of hunted, and the stone tools softened up the meat and plant foods so that he did not need to chew as much? Wrangham co-authored a that began with . It concluded that food processing, cooking in particular, accounted for the effect. Cooked food versus raw food and the number of neurons that can be supported in a brain has been . The primary reason why Wrangham’s hypothesis was initially dismissed was that archeological evidence for fires that long ago is almost nonexistent. When was published, the earliest evidence with wide acceptance only supported fires , where Israel is today, which is more than a million years after Wrangham’s estimated timeframe. Wrangham did what all bold scientists do: he made falsifiable predictions. If it turned out that no evidence of early fires was ever found, his hypothesis could begin looking shaky.
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