Posts tagged "biology"
398

Top 10 Myths About Evolution

1 If Humans Came From Apes, Why Aren’t Apes Evolving Into Humans?

Humans, apes, and monkeys are only distant evolutionary “cousins.” We come not from apes but from a common ancestor that was neither ape nor human that lived millions of years in the past. In fact, during the last seven million years many human-like species have evolved; some examples include Homo habilis, Homo erectus, and Homo neanderthalensis. All of these went extinct at different times, leaving just us to share the planet with a handful of other primates.

2 There Are Too Many Gaps in the Fossil Record for Evolution to Be True

In fact, there are lots of intermediate fossils. Archaeopteryx, for example, is one of the earliest known fossil birds with a reptilian skeleton and feathers. There is now evidence that some dinosaurs had hair and feathers. Therapsids are the intermediates between reptiles and mammals, Tiktaalik is an extinct lobe-finned fish intermediate to amphibians, there are now at least six intermediate fossil stages in the evolution of whales, and in human evolution there are at least a dozen intermediate fossil stages since hominids branched off from the great apes six million years ago. Considering the exceptionally low probability that a dead plant or animal will fossilize it is remarkable we have as many fossils as we do. First the dead animal has to escape the jaws of scavengers. Then is has to be buried under the rare circumstances that will cause it to fossilize instead of decay. Then geological forces have to somehow bring the fossil back to the surface to be discovered millions of years later by the handful of paleontologists looking for them

3 If Evolution Happened Gradually Over Millions of Years Why Doesn’t the Fossil Record Show Gradual Change?

Sudden changes in the fossil record are not missing evidence of gradualism; they are extant evidence of punctuation. Species are stable over long periods of time and so they leave plenty of fossils in the strata while in their stable state. The change from one species to another, however, happens relatively quickly (on a geological time scale) in a process called punctuated equilibrium. One species can give rise to a new species when a small “founder” group breaks away and becomes isolated from the ancestral group. This new founder group, as long as it remains small and detached, may experience relatively rapid change (large populations are genetically stable). The speciational change happens so rapidly that few fossils are left to record it. But once changed into a new species, the individuals will retain their phenotype for a long time, leaving behind many well-preserved fossils. Millions of years later this process results in a fossil record that records mostly stability. The punctuation is there in between the equilibrium.

4 No One Has Ever Seen Evolution Happen

Evolution is a historical science confirmed by the fact that so many independent lines of evidence converge to this single conclusion. Independent sets of data from geology, paleontology, botany, zoology, biogeography, comparative anatomy and physiology, genetics, molecular biology, developmental biology, embryology, population genetics, genome sequencing, and many other sciences each point to the conclusion that life evolved. Creationists demand “just one fossil transitional form” that shows evolution. But evolution is not proved through a single fossil. It is proved through a convergence of fossils, along with a convergence of genetic comparisons between species, and a convergence of anatomical and physiological comparisons between species, and many other lines of inquiry. (In fact we can see evolution happen—especially among organisms with short reproductive cycles that are subject to extreme environmental pressures. Knowledge of the evolution of viruses and bacteria is vital to medical science.)

5 Science Claims That Evolution Happens by Random Chance

Natural selection is not “random” nor does it operate by “chance.” Natural selection preserves the gains and eradicates the mistakes. To illustrate this, imagine a monkey at a typewriter. In order for the monkey to type the first 13 letters of Hamlet’s soliloquy by chance, it would take 26 (to the 13th power) number of trials for success. This is 16 times as great as the total number of seconds that have elapsed in the lifetime of the solar system. But if each correct letter is preserved and each incorrect letter eradicated, the phrase “tobeornottobe” can be “selected for” in only 335 trials, or just seconds in a computer program. Richard Dawkins defines evolution as “random mutation plus nonrandom cumulative selection.” It is the cumulative selection that drives evolution. The eye evolved from a single, light sensitive spot in a cell into the complex eye of today not by chance, but through thousands of intermediate steps, each preserved because they made a better eye. any of these steps still exist in nature in simpler organisms.

6 Only an Intelligent Designer Could Have Made Something as Complex as an Eye

The anatomy of the human eye shows that it is anything but “intelligently designed.” It is built upside down and backwards, with photons of light having to travel through the cornea, lens, aqueous fluid, blood vessels, ganglion cells, amacrine cells, horizontal cells, and bipolar cells, before reaching the light sensitive rods and cones that convert the light signal into neural impulses, which are then sent to the visual cortex at the back of the brain for processing into meaningful patterns. For optimal vision, why would an intelligent designer have built an eye upside down and backwards? This “design” only makes sense if natural selection built eyes from available materials, and in the particular configuration of the ancestral organism’s pre-existing organic structures. The eye shows the pathways of evolutionary history, not intelligent design.

7 Evolution is Only A Theory

All branches of science are based on theories, which are grounded in testable hypothesis and explain a large and diverse body of facts about the world. A theory is considered robust if it consistently predicts new phenomena that are subsequently observed. Facts are the world’s data. Theories are explanatory ideas about those data. Constructs and other non-testable statements are not a part of science. The theory of evolution meets all the criteria of good science, as determined by Judge William Overton in the Arkansas creationism trial:
• It is guided by natural law.
• It has to be explanatory by reference to natural law.
• It is testable against the empirical world.
• Its conclusions are tentative.
• It is testable and falsifiable.
If you can find fossil mammals in the same geological strata as trilobites then evolution would be falsified. No one has ever found such contradictory data.

8 Evidence for Human Evolution Has Turned Out to Be Fake, Frauds, or Fanciful

Eager to discredit evolution, creationists ignore hominid fossil discoveries and cherry pick examples of hoaxes and mistakes in the belief that mistakes in science are a sign of weakness. This is a gross misunderstanding of the nature of science, which constantly advances by using both its mistakes and the successes. Its ability to build cumulatively on the past is how science progresses. The self-correcting feature of the scientific method is one of its most powerful assets. Hoaxes like Piltdown Man, and honest mistakes like Nebraska Man, Calaveras Man, and Hespero-pithecus, are, in time, corrected. In fact, it wasn’t creationists who exposed these errors, it was scientists who did so. Creationists simply read about the scientific exposé of these errors, and then duplicitously claimed them as their own.

9 The Second Law of Thermodynamics Proves That Evolution is Impossible

The Second Law of Thermodynamics applies to closed, isolated systems. Since the Earth receives a constant input of energy from the sun—it is an open-dissipative system—entropy may decrease and order increase (though the sun itself is running down in the process). Thus, the Earth is not strictly a closed system and life may evolve without violating natural law. As long as the sun is burning, life may continue thriving and evolving, just like automobiles may be prevented from rusting, burgers can be heated in ovens, and all manner of things in apparent violation of Second Law entropy may continue. But as soon as the sun burns out, entropy will take its course and life on Earth will cease.

10 Evolution Can’t Account For Morality

As a social primate species we evolved a deep sense of right and wrong in order to accentuate and reward reciprocity and cooperation, and to attenuate and punish excessive selfishness and free riding. As well, evolution created the moral emotions that tell us that lying, adultery, and stealing are wrong because they destroy trust in human relationships that depend on truth-telling, fidelity, and respect for property. It would not be possible for a social primate species to survive without some moral sense. On the constitution of human nature is built the constitutions of human societies.

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Richard Dawkins - Laryngeal Nerve Causes Problems for Intelligent Design

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What Caused the Big Bang?

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Very Gradual Change We Can Believe In

Very Gradual Change We Can Believe In

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11

‘Supermice’ who can resist cancer and age almost half as fast as normal

If their powers were mirrored in humans it would create an average lifespan of 120 years, the researchers claim.

Scientists first modified the genes of the mice to make them resistant to cancer. In addition, they genetically increased the amount of a particular protein in the body, which can delay how quickly cells age.

The resulting mice age 40 per cent slower than those whose genes have not been modified, studies show.

Scientists have known since the 1990s of the age-defying powers of the protein, called telomerase.

The protein helps cells to regenerate, allowing them to stay younger for longer.

However, previous attempts to increase the amount of the protein in mice ended in failure when scientists found that it made them more susceptible to developing cancer.

In the latest study, published in the journal Cell, the scientists solved that problem by changing the genes of the mice first to make them resistant to the disease.

The researchers found that mice which had been created in this way had better muscle in old age, healthier skin tissue and fewer digestion problems.

“By simultaneously increasing the amounts of telomerase and the resistance to cancer we are able to delay ageing in mice and also to extend their life span by 40 per cent,” said Maria A. Blasco, from the Spanish National Cancer Research Centre (CNIO), who carried out the study with colleagues from Valencia University.

“These mice get to live for as long as the eldest mice in records of the same kind.

“If we were to parallel it to humans, then it would mean reaching 120 years of age and also to start ageing much later in life.”

She believes that the findings will be of interest to the beauty industry, which is already looking at the potential of using telemorase to fight the effects of aging.

Last year scientists at the University of Kentucky announced that they had been able to create a mouse resistant to cancer, even highly-aggressive types, using a tumour-suppressor gene called “Par-4” in the prostate.

At the time they claimed that the breakthrough could be used to create bone marrow transplantation which could be used to fight cancer cells in patients with the disease.

The first artificially created cancer-resistant mice were produced in the early years of this decade and showed that such resistance could also be inherited.

The mice all stem from a single cancer-resistant mouse discovered in 1999.

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Girl frozen in time may hold key to ageing
American scientists are keenly studying the DNA of a 17-year-old girl who still has the body and behaviour of a baby
Scientists are hoping to gain new insights into the mysteries of ageing by sequencing the genome of a 17-year-old girl who has the body and behaviour of a tiny toddler.
Brooke Greenberg is old enough to drive a car and next year will be old enough to vote — but at 16lb in weight and just 30in tall, she is still the size of a one-year-old.
Until recently she had been regarded as a medical oddity but a preliminary study of her DNA has suggested her failure to grow could be linked to defects in the genes that make the rest of humanity grow old.
If confirmed, the research could give scientists a fresh understanding of ageing and even suggest new therapies for diseases linked to old age.
“We think that Brooke’s condition presents us with a unique opportunity to understand the process of ageing,” said Richard Walker, a professor at the University of South Florida School of Medicine, who is leading the research team.
“We think that she has a mutation in the genes that control her ageing and development so that she appears to have been frozen in time.
“If we can compare her genome to the normal version then we might be able to find those genes and see exactly what they do and how to control them.”
Such research will be the focus of a conference at the Royal Society in London this week to be attended by some of the world’s leading age researchers.
It follows a series of scientific breakthroughs showing that the life span of many animals can be dramatically extended by making minute changes in single genes.
The work began with tiny worms known as C elegans, which normally live for only about a fortnight. Researchers have been able to extend their life span by up to 10 weeks by making small changes in certain genes.
Scientists have gone on to discover that mutating the same genes in mice had the same effect.
“Mice are genetically very close to humans,” said Cynthia Kenyon, professor of biochemistry at the University of California, San Francisco, who is a key speaker at the Royal Society.
“The implication is that ageing is controlled by a relatively small number of genes and that we might be able to target these with new therapies that would improve the quality and length of human life.”
The laboratory findings have been supported by research into humans, focusing on families whose members are long-lived. In one recent study Eline Slagboom, professor of molecular epidemiology at Leiden University, Holland, collected data on 30,500 people in 500 long-lived families to find the metabolic and genetic factors that make them special.
“Such people simply age slower than the rest of us,” she said. “Their skin is better, they have less risk of diseases of old age like diabetes, heart disease and hypertension and their ability to metabolise lipids and other nutrients is better. The question is: what is controlling all these different manifestations of slow ageing?
“So far, the evidence suggests that there could be just a few key genes in charge of it all. If we can find out where they are and how they work, it opens the way to new therapies against the diseases of ageing that could work in all of us.”
Walker and other researchers, including Kenyon, believe that finding the cause of Brooke Greenberg’s condition could be one way to pinpoint some of those genes.
Superficially, Brooke, who lives with her parents Howard and Melanie Greenberg and her three sisters in Reisterstown, a Baltimore suburb, is frozen in time. She looks and acts as if she were a small toddler — for 17 years her family has changed her nappies, rocked her to sleep and given her cuddles.
Brooke has shown some development, including crawling, smiling and giggling when tickled but she has never learnt to speak and still has her infant teeth.
But she has also suffered a succession of life-threatening health problems, including strokes, seizures, ulcers and breathing difficulties — almost as if she were growing old despite not growing up.
Howard Greenberg, Brooke’s father, said he wanted the genome research carried out in the hope it might help others.
He said: “Brooke is just a wonderful child. She is very pure. She still babbles just like a 6 month old baby but she still communicates and we always know just what she means.”
Walker and his colleagues, who are working with Brooke’s parents to ensure she benefits from any research findings, have just published a research paper which suggests that in reality some parts of her body have indeed aged — but slowly and all at different rates.
“Our hypothesis is that she is suffering from damage in the gene or genes that co-ordinate the way the body develops and ages,” he said.
“If we can use her DNA to find that mutant gene then we can test it in laboratory animals to see if we can switch if off and slow down the ageing process at will.
“Just possibly it could give us an opportunity to answer the question of why we are mortal.”

Girl frozen in time may hold key to ageing

American scientists are keenly studying the DNA of a 17-year-old girl who still has the body and behaviour of a baby

Scientists are hoping to gain new insights into the mysteries of ageing by sequencing the genome of a 17-year-old girl who has the body and behaviour of a tiny toddler.

Brooke Greenberg is old enough to drive a car and next year will be old enough to vote — but at 16lb in weight and just 30in tall, she is still the size of a one-year-old.

Until recently she had been regarded as a medical oddity but a preliminary study of her DNA has suggested her failure to grow could be linked to defects in the genes that make the rest of humanity grow old.

If confirmed, the research could give scientists a fresh understanding of ageing and even suggest new therapies for diseases linked to old age.

“We think that Brooke’s condition presents us with a unique opportunity to understand the process of ageing,” said Richard Walker, a professor at the University of South Florida School of Medicine, who is leading the research team.

“We think that she has a mutation in the genes that control her ageing and development so that she appears to have been frozen in time.

“If we can compare her genome to the normal version then we might be able to find those genes and see exactly what they do and how to control them.”

Such research will be the focus of a conference at the Royal Society in London this week to be attended by some of the world’s leading age researchers.

It follows a series of scientific breakthroughs showing that the life span of many animals can be dramatically extended by making minute changes in single genes.

The work began with tiny worms known as C elegans, which normally live for only about a fortnight. Researchers have been able to extend their life span by up to 10 weeks by making small changes in certain genes.

Scientists have gone on to discover that mutating the same genes in mice had the same effect.

“Mice are genetically very close to humans,” said Cynthia Kenyon, professor of biochemistry at the University of California, San Francisco, who is a key speaker at the Royal Society.

“The implication is that ageing is controlled by a relatively small number of genes and that we might be able to target these with new therapies that would improve the quality and length of human life.”

The laboratory findings have been supported by research into humans, focusing on families whose members are long-lived. In one recent study Eline Slagboom, professor of molecular epidemiology at Leiden University, Holland, collected data on 30,500 people in 500 long-lived families to find the metabolic and genetic factors that make them special.

“Such people simply age slower than the rest of us,” she said. “Their skin is better, they have less risk of diseases of old age like diabetes, heart disease and hypertension and their ability to metabolise lipids and other nutrients is better. The question is: what is controlling all these different manifestations of slow ageing?

“So far, the evidence suggests that there could be just a few key genes in charge of it all. If we can find out where they are and how they work, it opens the way to new therapies against the diseases of ageing that could work in all of us.”

Walker and other researchers, including Kenyon, believe that finding the cause of Brooke Greenberg’s condition could be one way to pinpoint some of those genes.

Superficially, Brooke, who lives with her parents Howard and Melanie Greenberg and her three sisters in Reisterstown, a Baltimore suburb, is frozen in time. She looks and acts as if she were a small toddler — for 17 years her family has changed her nappies, rocked her to sleep and given her cuddles.

Brooke has shown some development, including crawling, smiling and giggling when tickled but she has never learnt to speak and still has her infant teeth.

But she has also suffered a succession of life-threatening health problems, including strokes, seizures, ulcers and breathing difficulties — almost as if she were growing old despite not growing up.

Howard Greenberg, Brooke’s father, said he wanted the genome research carried out in the hope it might help others.

He said: “Brooke is just a wonderful child. She is very pure. She still babbles just like a 6 month old baby but she still communicates and we always know just what she means.”

Walker and his colleagues, who are working with Brooke’s parents to ensure she benefits from any research findings, have just published a research paper which suggests that in reality some parts of her body have indeed aged — but slowly and all at different rates.

“Our hypothesis is that she is suffering from damage in the gene or genes that co-ordinate the way the body develops and ages,” he said.

“If we can use her DNA to find that mutant gene then we can test it in laboratory animals to see if we can switch if off and slow down the ageing process at will.

“Just possibly it could give us an opportunity to answer the question of why we are mortal.”

21
Moderator: We're here today to debate the hot new topic, evolution versus Intelligent Des---
(Scientist pulls out baseball baat.)
Moderator: Hey, what are you doing?
(Scientist breaks Intelligent Design advocate's kneecap.)
Intelligent Design advocate: YEAAARRRRGGGHHHH! YOU BROKE MY KNEECAP!
Scientist: Perhaps it only appears that I broke your kneecap. Certainly, all the evidence points to the hypothesis I broke your kneecap. For example, your kneecap is broken; it appears to be a fresh wound; and I am holding a baseball bat, which is spattered with your blood. However, a mere preponderance of evidence doesn't mean anything. Perhaps your kneecap was designed that way. Certainly, there are some features of the current situation that are inexplicable according to the "naturalistic" explanation you have just advanced, such as the exact contours of the excruciating pain that you are experiencing right now.
Intelligent Design advocate: AAAAH! THE PAIN!
Scientist: Frankly, I personally find it completely implausible that the random actions of a scientist such as myself could cause pain of this particular kind. I have no precise explanation for why I find this hypothesis implausible --- it just is. Your knee must have been designed that way!
Intelligent Design advocate: YOU BASTARD! YOU KNOW YOU DID IT!
Scientist: I surely do not. How can we know anything for certain? Frankly, I think we should expose people to all points of view. Furthermore, you should really re-examine whether your hypothesis is scientific at all: the breaking of your kneecap happened in the past, so we can't rewind and run it over again, like a laboratory experiment. Even if we could, it wouldn't prove that I broke your kneecap the previous time. Plus, let's not even get into the fact that the entire universe might have just popped into existence right before I said this sentence, with all the evidence of my alleged kneecap-breaking already pre-formed.
Intelligent Design advocate: That's a load of bullshit sophistry! Get me a doctor and a lawyer, not necessarily in that order, and we'll see how that plays in court!
Scientist (turning to audience): And so we see, ladies and gentlemen, when push comes to shove, advocates of Intelligent Design do not actually believe any of the arguments that they profess to believe. When it comes to matters that hit home, they prefer evidence, the scientific method, testable hypotheses, and naturalistic explanations. In fact, they strongly privilege naturalistic explanations over supernatural hocus-pocus or metaphysical wankery. It is only within the reality-distortion field of their ideological crusade that they give credence to the flimsy, ridiculous arguments which we so commonly see on display. I must confess, it kind of felt good, for once, to be the one spouting free-form bullshit; it's so terribly easy and relaxing, compared to marshaling rigorous arguments backed up by empirical evidence. But I fear that if I were to continue, then it would be habit-forming, and bad for my soul. Therefore, I bid you adieu.

Richard Dawkins interviews Jonathan Kingdon (Part 2/4)

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Richard Dawkins interviews Jonathan Kingdon (Part 1/4)

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Freeman Dyson Photo from Long Now Seminar, San...Image via Wikipedia

Freeman Dyson: Let’s look for life in the outer solar system

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A Conversation with Richard Dawkins (1/12)

For the other 11 parts of this interview please go http://www.youtube.com/view_play_list?p=9EF8FE04FE423B06