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aamukherjee A Slice of Entropie -
alchymista Alchymista -
crownedrose Fading Like A Dead Star -
expose-the-light Quarks to Quasars -
ikenbot CWL -
abluegirl A Blue Girl -
perscientiamlibertas A Matter of the Most Pleasant Fraternal Confidence
scinerds Said:
Hello! There’s nothing to be embarrassed about. Sometimes certain topics slip under the education radar, and it’s wonderful you’d like to learn about it on your own!
To start, I feel everyone should own a copy of Charles Darwin’s The Origin Of Species. There are a lot of versions out there - short, long, revised, etc - so you’ll need to do some research on which version you would like to start off on.
I also really enjoy Your Inner Fish by Neil Shubin. The way he writes is amazing, and easy to understand whether you’re new to the subject or not.
Some other books that may interest you are listed below:
- Why Evolution Is True by Jerry. A Coyne.
- There’s also Richard Dawkins books like The Greatest Show On Earth and The Ancestor’s Tale.
- What Evolution Is by Ernst Mayr
- Shadows Of Forgotten Ancestors by Carl Sagan and Ann Druyan
- Evolution: The Triumph Of An Idea by Carl Zimmer
- Dinosaur In A Haystack by Stephen Jay Gould (plus his many others)
- Evolution: What The Fossils Say And Why It Matters by Donald R. Prothero
- TED talks on evolution (thanks goes to cicatrose for reminding me of the awesomeness)
I know I’ve left a lot of books out (even many I own/have read), but these are a few that may be great introductions for you. There is a list on Good Reads you may also want to take a look at which lists their best books on evolution (based on reviews, it looks). As well, if you search “evolution” on places like Amazon or your local book store website, you’ll be able to get a good list of ones I’ve not listed here.
Again, there are just so many books out on evolution (way too many to list!), and I do want to stress that everyone has their own opinions on which books they feel are best, more accurate, etc. In the end, I definitely suggest reading a bit about each book on Amazon (or similar sites) to see if you feel these will be a good starting point for you. I’ve found the more books I read, the better I understand topics - like evolution - as a whole. You get different opinions from the authors, and I feel it helps when cross checking information once you become more acquainted to the topics you’re reading about. I do this a lot with palaeontology studies, for example.
When it comes to scientific papers, there are some in book format and many available online. A good place to start would be searching “evolution” on sites like Google Scholar, University websites, PLOS ONE, Nature, etc.
I hope this post is of help!
* * *
Hey, followers, got some awesome evolution books you have read that I totally forgot to list here? Send them over via ask and I’ll make a compiled list to put up on our blog!
crownedrose
Why Some People Faint When They See Blood
Most phobias—of cockroaches, spiders, heights or clowns—don’t induce the wooziness typical of blood phobia. Some of the people who fear of blood will pass out at the sight of the stuff. Popular Science explains why this is so strange:
Despite it being relatively common—3 to 4 percent of people suffer from blood phobia or a related disorder—the symptoms of it are totally different from most phobias: phobics’ blood pressure and heart rate will rise then drop when they see blood, as opposed to the just-heart-racing caused by most fears.
Not much research has been conducted to explain why this happens, John Sanford of Stanford Medicine writes. But those studies that have examined the topic have yielded mixed results. Some say that fainting at the sight of blood may be the human equivalent of playing opossum—pretending to be dead so that a dangerous predator will lose interest. Others think that the physiological reaction some experience at the sight of blood may be an evolutionary adaptation. If a caveman got stabbed in the foot while out on a hunting trip, Sanford explains, he may have a better chance of surviving if his blood pressure drops, helping him to avoid bleeding to death.
Yet blood phobia presumably would not — at least in modern times — provide much in the way of selective advantage. Emergency medical responders generally can reach you quickly and stanch bleeding. And if you faint, you can sustain a worse injury by falling.
So besides being useful for dramatic effect in the movies, it seems blood phobia—perhaps like the appendix or wisdom teeth—is an evolutionary throwback that has largely outlived its usefulness. Now, if those of us who suffer from the phobia could only convince our pounding hearts of this logic.
abluegirl- In where Lynn Margulis socks it to Richard Dawkins and his militant Neo-Darwinist views with a simple reply based on evidence.
- Richard Dawkins: If you take the standard story for ordinary animals, what’s wrong with it, you’ve got a distribution of animals, you’ve got a promontory or an island or something so you end up with two distributions there, just geographical, and then on either side of this promontory you get different selection pressures so this one starts to evolve that way, this one starts to evolve that way and what’s wrong with that? It’s highly plausible, it’s economical, it’s parsimonious. Why on earth would you want to drag in symbiogenesis when it’s so unparsimonious and uneconomical?
- Lynn Margulis: Because it’s there.
ikenbotGood ol’ Ardi - Ardipithecus Ramidus
Ardipithecus ramidus was first reported in 1994; in 2009, scientists announced a partial skeleton, nicknamed ‘Ardi’.
The foot bones in this skeleton indicate a divergent large toe combined with a rigid foot – it’s still unclear what this means concerning bipedal behavior. The pelvis, reconstructed from a crushed specimen, is said to show adaptations that combine tree-climbing and bipedal activity. The discoverers argue that the ‘Ardi’ skeleton reflects a human-African ape common ancestor that was not chimpanzee-like. A good sample of canine teeth of this species indicates very little difference in size between males and females in this species.
Ardi’s fossils were found alongside faunal remains indicating she lived in a wooded environment. This contradicts the open savanna theory for the origin of bipedalism, which states that humans learned to walk upright as climates became drier and environments became more open and grassy.
Over 100 specimens of Ardipithecus ramidus have been recovered in Ethiopia. Even though it has some ape-like features (as do many other early human species), it also has key human features including smaller diamond-shaped canines and some evidence of upright walking. It may have descended from an earlier species of Ardipithecus that has been found in the same area of Ethiopia, Ardipithecus kadabba.
Ardipithecus ramidus individuals were most likely omnivores, which means they enjoyed more generalized diet of both plants, meat, and fruit. Ar. ramidus did not seem to eat hard, abrasive foods like nuts and tubers.
How do we know they were omnivores?
The enamel on Ar. ramidus teeth remains show it was neither very thick nor very thin. If the enamel was thick, it would mean Ar. ramidus ate tough, abrasive foods. If the enamel was thin, this would suggest Ar. ramidus ate softer foods such as fruit. Instead, A. ramidus has an enamel thickness between a chimpanzee’s and later Australopithecus or Homo species, suggesting a mixed diet. However, the wear pattern and incisor sizes indicate Ar. ramidus was not a specialized frugivore ( fruit-eater). Ar. ramidus probably also avoided tough foods, as they did not have the heavy chewing specializations of later Australopithecus species.
The Brazilian Treehopper
Yep, it’s a real thing. Google it!
That crazy ornament thing on its body isn’t some weird antenna, instead those “balls” are hollow spheres of chitin probably to try and scare away predators. Would you want to chew on that? And those bristles surrounding the spheres are most likely used for some unknown tactile function.Read more at Why Evolution is True
(via the-science-llama)
Actually a pretty darned good analogy.
Indeed!
Though I could also see this analogy confusing someone without a good understanding of evolution. The point is: It’s not really random; it just had a very complex set of options determined by the environment. (Did I just make it more confusing?! lol)
![writingcapital:
A third [evolutionary] advance is in a way the most important, since it is the one used by paleontologists to distinguish reptiles from mammals. The lower jaw of reptiles contains several bones, of which two are important to us. One of these, the dentary, bears the teeth while the other, the articular, smaller and at the hind end of the jaw, forms part of the hinge between the lower and upper jaw (Figure 9-8). The other part of this hinge is the quadrate, a small bone in the head portion of the skull, or cranium. Immediately behind these two small jaw bones is the middle ear, within which sound waves are amplified and transmitted from a special nerve to the brain. In reptiles, amphibians, and fishes, this amplification is carried out by a single small bone. By contrast, the lower jaw of mammals consists only of the tooth-bearing (dentary) bone, which is hinged to another bone, the squamosal, also in the cranium. The two bones that form the hinge of the reptilian jaw have not disappeared. They are represented in mammals by two small bones in the middle ear connected with the counterpart of the single reptilian ear bone. In reptiles, amplification of sound waves in the middle ear, carried out by a single bone, is relatively inefficient. The three bones in the mammalian ear do this job much more effectively, so that the hearing of mammals is much better than that of reptiles.
In order to classify fossil animals neatly and clearly as either reptiles or mammals, most paleontologists and nearly all textbooks classify as reptiles all bony-limbed animals that have a liquid-filled amniotic egg and a jaw hinge formed by the two small bones, articular and quadrate, along with a single ear bone. Mammals differ in having the tooth-bearing (dentary) lower jaw bone articulated directly with a bone of the cranium (squamosal), plus three small bones in the middle ear. Tooth structure also helps in classifying them. Nevertheless, an animal that has almost mammalian teeth but a reptilian jaw hinge and middle ear bone is called a reptile. Mammallike reptiles are all classified as reptiles on the basis of this character, even though the advanced dog-tooth has teeth that resemble those of primitive mammals more than they resemble the teeth of the earliest mammallike reptiles or their immediate ancestors, the pelycosaurs. Likewise, the earliest animals having three bones in the middle ear are called mammals, although, like the primitive mammals of modern Australia—the spiny anteater and platypus (monotremes)—they may well have laid eggs, lacked nipples or teats, had skeletons showing some reptilian features such as shoulder girdles, and had chromosomes resembling those of reptiles.
— Stebbins - Darwin to DNA, Molecules to Humanity, pp. 289-91
I find this strangely profound: everyone knows the difference between a reptile and a mammal upon seeing one, but once all the fragile details are stripped away, there’s only a single, trivial difference between them; it’s this one silly little criterion that informs all of our (taxonomical) knowledge about species long-extinct. I suspect that the taxonomies of many disciplines are like this.
The text alongside fig. 9-8 reads:
Figure 9-8.A series of skulls showing a few of the numerous transitional forms that, via a series of adaptive radiations, resulted eventually in the origin of modern mammals (a)–(c): Three typical reptiles. (a) A primitive Captorhinus that, like early amphibians and modern turtles, has only one pair of openings in the skull in addition to the nostrils. (b) A primitive ancestor of lizards, Youngina. (c) A modern lizard, Varanus. (d)–(i): Six reptiles that were on or near the line leading to mammals. (d) and (e) Two pelycosaurs that were typical reptiles but show the beginnings of tooth differentiation. Note that the hindmost bone of the lower jaw (angular, a) is nearly as large as the tooth-bearing bone (dentary, dn). (f) and (g) Two early mammallike reptiles, showing further tooth differentiation, plus reduction in size of the angular bone. (h) and (i) Two later forms of reptiles that, with respect to tooth differentiation and reduction of the angular bone, were much like mammals. Diarthrognathus was almost completely intermediate between reptiles and mammals. (j)–(l): Three kinds of mammals. (j) Sinoconodon, the earliest of these, still retained a number of reptilian features. (k) A later form, Deltatheridium, was very similar to modern shrews. (l) A modern opossum (Didelphys). The skulls are drawn at different scales of magnification. Those in the center column are at natural size or somewhat reduced; those in the right column are somewhat magnified.](http://24.media.tumblr.com/d082b675deefe9f78ed170cfb15a12cd/tumblr_mfetorj2Lp1r8gcifo1_500.jpg)
A third [evolutionary] advance is in a way the most important, since it is the one used by paleontologists to distinguish reptiles from mammals. The lower jaw of reptiles contains several bones, of which two are important to us. One of these, the dentary, bears the teeth while the other, the articular, smaller and at the hind end of the jaw, forms part of the hinge between the lower and upper jaw (Figure 9-8). The other part of this hinge is the quadrate, a small bone in the head portion of the skull, or cranium. Immediately behind these two small jaw bones is the middle ear, within which sound waves are amplified and transmitted from a special nerve to the brain. In reptiles, amphibians, and fishes, this amplification is carried out by a single small bone. By contrast, the lower jaw of mammals consists only of the tooth-bearing (dentary) bone, which is hinged to another bone, the squamosal, also in the cranium. The two bones that form the hinge of the reptilian jaw have not disappeared. They are represented in mammals by two small bones in the middle ear connected with the counterpart of the single reptilian ear bone. In reptiles, amplification of sound waves in the middle ear, carried out by a single bone, is relatively inefficient. The three bones in the mammalian ear do this job much more effectively, so that the hearing of mammals is much better than that of reptiles.
In order to classify fossil animals neatly and clearly as either reptiles or mammals, most paleontologists and nearly all textbooks classify as reptiles all bony-limbed animals that have a liquid-filled amniotic egg and a jaw hinge formed by the two small bones, articular and quadrate, along with a single ear bone. Mammals differ in having the tooth-bearing (dentary) lower jaw bone articulated directly with a bone of the cranium (squamosal), plus three small bones in the middle ear. Tooth structure also helps in classifying them. Nevertheless, an animal that has almost mammalian teeth but a reptilian jaw hinge and middle ear bone is called a reptile. Mammallike reptiles are all classified as reptiles on the basis of this character, even though the advanced dog-tooth has teeth that resemble those of primitive mammals more than they resemble the teeth of the earliest mammallike reptiles or their immediate ancestors, the pelycosaurs. Likewise, the earliest animals having three bones in the middle ear are called mammals, although, like the primitive mammals of modern Australia—the spiny anteater and platypus (monotremes)—they may well have laid eggs, lacked nipples or teats, had skeletons showing some reptilian features such as shoulder girdles, and had chromosomes resembling those of reptiles.
— Stebbins - Darwin to DNA, Molecules to Humanity, pp. 289-91
I find this strangely profound: everyone knows the difference between a reptile and a mammal upon seeing one, but once all the fragile details are stripped away, there’s only a single, trivial difference between them; it’s this one silly little criterion that informs all of our (taxonomical) knowledge about species long-extinct. I suspect that the taxonomies of many disciplines are like this.
The text alongside fig. 9-8 reads:
Figure 9-8.
A series of skulls showing a few of the numerous transitional forms that, via a series of adaptive radiations, resulted eventually in the origin of modern mammals (a)–(c): Three typical reptiles. (a) A primitive Captorhinus that, like early amphibians and modern turtles, has only one pair of openings in the skull in addition to the nostrils. (b) A primitive ancestor of lizards, Youngina. (c) A modern lizard, Varanus. (d)–(i): Six reptiles that were on or near the line leading to mammals. (d) and (e) Two pelycosaurs that were typical reptiles but show the beginnings of tooth differentiation. Note that the hindmost bone of the lower jaw (angular, a) is nearly as large as the tooth-bearing bone (dentary, dn). (f) and (g) Two early mammallike reptiles, showing further tooth differentiation, plus reduction in size of the angular bone. (h) and (i) Two later forms of reptiles that, with respect to tooth differentiation and reduction of the angular bone, were much like mammals. Diarthrognathus was almost completely intermediate between reptiles and mammals. (j)–(l): Three kinds of mammals. (j) Sinoconodon, the earliest of these, still retained a number of reptilian features. (k) A later form, Deltatheridium, was very similar to modern shrews. (l) A modern opossum (Didelphys). The skulls are drawn at different scales of magnification. Those in the center column are at natural size or somewhat reduced; those in the right column are somewhat magnified.
BILLIONS of years ago, a tiny cyanobacterium cracked open a water molecule - and let loose a poison that wrought death and destruction on an epic scale. The microbe had just perfected photosynthesis, a process that freed the oxygen trapped inside water and killed early Earth’s anaerobic inhabitants.
Now, for the first time, geologists have found evidence of the crucial evolutionary stage just before cyanobacteria split water. The find offers a unique snapshot of the moment that made the modern world. With the advent of photosynthesis came an atmosphere dominated by oxygen and, ultimately, the diversity of life forms that we know today.
“This was the biggest change that ever occurred in the biosphere,” says Kevin Redding at Arizona State University in Tempe. “The extinction caused by oxygen was probably the largest ever seen, but at the same time animal life wouldn’t be possible without oxygen.”
Image source.
(via Captured: the moment photosynthesis changed the world)
Researchers Solve Darwin’s ‘Abominable Mystery’
Research by Indiana Univ. paleobotanist David Dilcher and colleagues in Europe sheds new light on what Charles Darwin famously called “an abominable mystery:” the apparently sudden appearance and rapid spread of flowering plants in the fossil record.
Writing in the Proceedings of the National Academy of Sciences, the researchers present a scenario in which flowering plants, or angiosperms, evolved and colonized various types of aquatic environments over about 45 million years in the early to middle Cretaceous Period.
Read more: http://www.laboratoryequipment.com/news/2012/12/researchers-solve-darwin%E2%80%99s-%E2%80%98abominable-mystery%E2%80%99
Frogfish: The Ocean’s Disguise Artists
Biomimicry is one of evolution’s most mind-blowing avenues of adaptation. It’s one thing to adapt thanks to maxing out the biological limits of speed, or selecting for the ever-longer, better-feeding necks of giraffes or the ability to use a new, untapped food source at the bottom of the ocean. But to become another life form? It shows us that natural selection is not only a powerful force, but also a delicate one, fine-tuning things like colors and patterns like only the finest human artists can.
Above are three examples of frogfish biomimicry, a family of fish that separately mimics algae, sponges and even sea urchins. They evolved these costumes as a way to avoid predators and become better predators themselves. Check out an in-depth post about frogfish biomimicry at Why Evolution is True (wait until you see them eat!), and if you want more here’s a whole website (Comic Sans warning!) dedicated to frogfish camo.
These guys even give Peeta Mellark a run for his money:
Symbiogenesis is the merging of two separate organisms to form a single new organism. The idea originated with Konstantin Mereschkowsky in his 1926 book Symbiogenesis and the Origin of Species, which proposed that chloroplasts originate from cyanobacteria captured by a protozoan.
Ivan Wallin also supported this concept in his book “Symbionticism and the Origins of Species”. He suggested that bacteria might be the cause of the origin of species, and that species creation may occur through endosymbiosis. Today both chloroplasts and mitochondria are believed, by those who ascribe to the endosymbiotic theory, to have such an origin.
“Animals are gentle, and kind.”
In Acquiring Genomes: A Theory of the Origins of Species, biologist Lynn Margulis argued later that symbiogenesis is a primary force in evolution. According to her theory, acquisition and accumulation of random mutations are not sufficient to explain how inherited variations occur; rather, new organelles, bodies, organs, and species arise from symbiogenesis. Whereas the classical interpretation of evolution (the modern evolutionary synthesis) emphasizes competition as the main force behind evolution, Margulis emphasizes cooperation. She argues that bacteria along with other microorganisms helped create the conditions that we require for life, such as oxygen.
Margulis believes that these microorganisms make up a major component in Earth’s biomass and that they are the reason current conditions on earth are maintained. She also believes that the DNA in the cytoplasm of animal, plant, fungal and protist cells, rather than resulting from mutations, resulted from genes from bacteria that became organelles. She claimed that bacteria are able to exchange genes more quickly and more easily, and because of this, they are more versatile, which is why life was able to evolve so quickly.
(via ikenbot)
