The Evolution of Life
In its 4540 million (4.54 billion) years circling the sun, Earth has provided a home for life that has become more and more complex. [The timeline can be seen here in more detail.]
- for the last 3600 million years, simple cells (prokaryotes);
- for the last 3400 million years, photosynthetic cyanobacteria
- for the last 2000 million years, complex cells (eukaryotes);
- for the last 1000 million years, multicellular life;
- for the last 600 million years, simple animals;
- for the last 550 million years, bilaterians,
animals with a front end and a back end,
as well as an upside and a downside;
- for the last 500 million years, fish and proto-amphibians;
- for the last 475 million years, land plants;
- for the last 400 million years, insects and plants with seeds;
- for the last 360 million years, amphibians;
- for the last 300 million years, reptiles;
- for the last 200 million years, mammals;
- for the last 150 million years, birds;
- for the last 130 million years, flowers;
- for the last 60 million years, the primates,
- for the last 20 million years, the family Hominidae (great apes);
- for the last 2.5 million years, the genus Homo (human predecessors);
- for the last 200,000 years, anatomically modern humans.
Image retrieved here [source unknown]
Well-Preserved Find 1.8 Million Years Old Drastically Simplifies Evolutionary Picture
- by Robert Lee Hotz
"A newly discovered 1.8 million-year-old skull offers evidence that humanity’s early ancestors emerged from Africa as a single adventurous species, not several species as believed, drastically simplifying human evolution, an international research team said Thursday.
The skull—the most complete of its kind ever discovered—is “a really extraordinary find,” said paleoanthropologist Marcia Ponce de Leon at the University of Zurich’s Anthropological Institute and Museum, who helped analyze it. “It is in a perfectly preserved state.”
Unearthed at Dmanisi in Georgia—an ancient route in the Caucasus for the first human migrations out of Africa—the skull was found at a spot where partial fossils of four other similar individuals and a scattering of crude stone tools had been found several years ago. They all date from a time when the area was a humid forest where saber-tooth tigers and giant cheetahs prowled. Preserved in siltstone beneath the hilltop ruins of a medieval fortress, the remains are the earliest known human fossils outside Africa, experts said.
David Lordkipanidze, director of the Georgian National Museum, who led the team, reported the discovery in Science. The primitive skull was first uncovered on Aug. 5, 2005—his birthday. “It was a very nice present,” he said.
Taken together, the finds at Dmanisi are especially important because experts in evolution could analyze the physical differences between individuals living in the same place at the same time almost 2 million years ago, when humankind first emerged from Africa to people the world, according to Yale University anthropologist Andrew Hill.
"It gives you a chance to look at variation for the first time," said Dr. Hill, who was not involved in the discovery" (read more).
***Hmm. I need to read the study ASAP.
(Source: Wall Street Journal)
Those who cavalierly reject the Theory of Evolution, as not adequately supported by facts, seem quite to forget that their own theory is supported by no facts at all. Like the majority of men who are born to a given belief, they demand the most rigorous proof of any adverse belief, but assume that their own needs none.
"In the age of information, ignorance is a choice." - Donnie Miller
There is overwhelming evidence for the theory of evolution, Those who wish to find this evidence need only an open mind and the desire to learn, as the evidence is not at all kept in hiding. Below are a few credible sources for those who are curious about what evolution is and the supporting evidence for the theory. Please add to this list as you see fit.
How did feathers evolve? A TED-Ed animation explores.
When you think about it, feathers are pretty amazing. The most complex integumentary structures (y’know — integumentary — stuff like skin, hair, scales, hooves) found in vertebrates, feathers have graced the bodies of animals since the age of dinosaurs, evolving to assist in taking flight, wicking off water, and looking fly for the ladies.
150 Million Years of Fish Evolution in One Handy Figure
Have you ever wished you could have the entire 150 million years of spiny-rayed fish evolution in convenient poster form? Well, wait no longer. Your happy day is here! Trust me … this is one poster featuring mullets you will not be embarrassed to display.
Plus, you can use it as a way to explore diversity and procrastinate. Not feeling like work? Simply glance over and … morwongs?! How did I never know such things existed? Maybe I’ll just have a quick … [2 hours pass]
In this figure, you can see how all the spiny-finned fish (acanthomorphs) — more than 18,000 species of them, which represent nearly one-third of living vertebrates — are related to one another. To accomplish this, the scientists inferred the relationships from the sequences of 10 genes from 520 spiny-rayed fin fish representing most of their families. They combined this data with that of 37 fossil “age constraints” used as reality checks on the actual timing of evolutionary shifts.
So that you can savor appropriately, it’s worth noting that this section of the vertebrate family tree has evidently given scientists significant difficulty, for the team who created it write in July in the Proceedings of the National Academy of Sciencesthat this group of fish has long “remained the last frontier” in drawing the family tree of living vertebrates and that it has presented “one of the most unyielding problems in vertebrate phylogenetics”. Blood… sweat… probably tears went into the creation of this image. Which makes its arrival all the more a moment to appreciate.
These prickly-finned fish include most of the fishes you think of as fish, with several major exceptions including sharks, sturgeon, trout, and salmon. They include fish that live in high mountain lakes and at the bottom of ocean trenches, fish flat as a pancake and puffy (though not fluffy) as a pillow. As advertised, they all have characteristic sharp, bony spines in their fins that any angler can tell you that you must mind when removing a squirming, slippery, and likely panicked fish from the hook.
The scientists found that the group likely evolved in the Early Cretaceous, about 150 million years ago. It’s a bit weird to think about what that means — that the tropical reefs of the Age of Dinosaurs — and all fish-containing ages prior — contained none of the tropical reef fish we recognize today (but what wonders did they contain?).
In the past, scientists wondered what circumstances or events led this group to evolve so much. Some suggested coral reefs were the cradle of the group’s diversity. But in the PNAS study, the five lineages within the group that diversified the most are found in four very different habitats: freshwater (cichlids), open ocean (tuna and friends), cold temperate seafloor (snailfishes), and coral reefs (blennies and gobies). This seemingly confounds any simple explanation for the massive success of the group.
The scientists also found that this group of fish didn’t seem to diversify much in response to the End-Cretaceous Mass Extinction. You can see this in the figure above. The dashed circle is when the Really Big Rock Hit Planet Earth. There doesn’t seem to be a big burst of evolution in its aftermath — that is, a whole lot of new lineages created all at once, perhaps to fill niches vacated by the Really Big Rock. Although it’s well established that many groups of snakes, lizards, birds, and mammals diversified significantly in response to the asteroid strike (although some major groups of these animals did not), it appears that this giant piscine group of vertebrates remained relatively unaffected by what was for many terrestrial vertebrates an Earth-shattering opportunity.
Near T.J., Dornburg A., Eytan R.I., Keck B.P., Smith W.L., Kuhn K.L., Moore J.A., Price S.A., Burbrink F.T. & Friedman M. & (2013). Phylogeny and tempo of diversification in the superradiation of spiny-rayed fishes, Proceedings of the National Academy of Sciences, 110 (31) 12738-12743. DOI:10.1073/pnas.1304661110
This concise pamphlet provides answers to common objections to evolution, such as: If humans came from apes, why aren’t apes evolving into humans?; Only an intelligent designer could have made something as complex as an eye; The second law of thermo-dynamics proves that evolution is impossible; Evolution can’t account for morality; and more…
Did you know? Whales’ flippers, or pectoral fins, share bone structure with the human arm and hand.
In fact, the bones of cetacean flippers are the same kinds of bones as in the human arm, with an upper arm bone, two forearm bones, and hand, wrist, and finger bones. In whales, fingers are elongated and may have additional bones.
Read more on whales’ amazing adaptations here.
Just because you’re ignorant and don’t understand what evolution even is doesn’t mean atheists blindly believe in evolution. It is not only atheists that accept evolution as true. Many christians, and in fact most people that actually understand the theory of evolution, also accept it as being true. Why? Because it is and the evidence is overwhelming.
A common argument is “there has never been evidence of macro-evolution (major evolutions in one species that creates another species)”. Species do not create species. Speciation occurs over hundreds or thousands of generations, and there is no distinct line that separates a species from another. It is merely when the new species and older species, or the species that come from the same ancestor, can no longer produce viable offspring. Donkeys and horses can produce mules together, but the mules are infertile. Thus, donkeys and horses are different species.
Dogs do not give birth to cats. However, wolves give birth to friendly wolves and mean wolves. The friendly wolves can be selectively bred to produce more friendly wolves. There is no point at which the wolf’s offspring suddenly become modern dogs. It took a countless number of generations and tiny changes that build up over time. It is not at all noticeable from our perspective since we rarely live longer than 80-90 years, and this is a process that takes thousands and millions.
You could also say that there has only been evidence of micro-evolution (small changes in singular species in traits already possessed by that species). In the few billion years since life arose on Earth, it is ridiculous to suggest that small changes are made but the species remain as they are. Over millions of years, those changes build up on each other so that new species emerge.
This is a process that took an incredible amount of time, but a relatively short amount of time from the perspective of the cosmos. To the cosmos, this is what it looked like:
It is quite obvious that you are the one with no true understanding or perception. It is quite obvious that you are the one swallowing up all the bullshit you’ve been fed your entire life. You rely on faith. We rely on facts. Only empirical evidence and raw data should be agreed with, and only conditionally (only until better data and evidence comes along that doesn’t support it). Scientists do not hide their findings. Their experiments and observations are testable and repeatable.
And we do actually question what scientists say. That is the basis for the scientific method, to test and get falsifiable results (results that can be proven wrong with contradictory empirical evidence). Scientists publish their papers in peer-reviewed journals. Now, on that some facts tend to be more ‘maybes’ and ‘most likely to’ that plain laws, well, that actually has to do too with the falsifiability of the scientific method. Just think about the black swan theory. The fact that you ‘can’t’ achieve a 100% certainty rate doesn’t mean that the theory is likely to change or probably wrong and inadequate.
There is nothing about your faith that is being tested. You refuse to test your faith by refusing to look at the facts. You instead swallow up the creationist garbage and see their twisted version of evolution. If you were to actually understand the real evolution, if you were to actually ask the right questions and read about it rather than spouting the same old bullshit we educated people have to listen to day in and day out, then you would be testing your faith.
For all of human history, people have believed in the concept of ‘intelligent design’ or ‘sentient causation’ to explain natural occurances that were not understood. Thor caused thunder. Poseidon caused floods. God created man. On and on and on. Science has sytematically proven each of these wrong. There seems to be some underlying need in human beings to anthropomorphize the cause of everything. Why do people continue to believe that a sentient being designed the universe? Creationism is the belief that introducing a conscious creator into the equation solves it, whereas in reality all it does is remove it one step. Who created the creator? Did it simply create itself out of nothing for no reason? Why is that more believable than the idea that the universe simply created itself out of nothing for no reason? Perhaps it never had a creation and has existed forever. If so, why is that more believable than the idea that the universe had no creation and existed forever?
Myth and religion have been wrong at every turn. Science may never prove what created the universe, but why bet on the idea that has been consistently proven wrong?
The word “theory” can be used to mean something speculative and tentative. In everyday speech it probably usually is used in that sense. Scientists very often use it in a much more positive sense. I think the easiest way is to use the ordinary language word “fact”. In the ordinary language sense of the word fact, evolution is a fact.
One thing all real scientists agree upon is the fact of evolution itself. It is a fact that we are cousins of gorillas, kangaroos, starfish, and bacteria. Evolution is as much a fact as the heat of the sun. It is not a theory, and for pity’s sake, let’s stop confusing the philosophically naive by calling it so. Evolution is a fact.
Both are quotes by Richard Dawkins