Why Do Zebras Have Stripes?

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Why Do Zebras Have Stripes? Scientists Have The Answer -- The Guardian

There have been many explanations for the zebra’s impressive stripes. New research strongly suggests that they have evolved to deter parasitic flies.

The zebra’s striped coat is simultaneously extraordinary and stunning. So wondrous, in fact, that many people have imagined it to be evidence of God’s infinitely artistic hand. Over the years, there have been many more rational explanations, but that all-important scientific consensus has remained elusive.

Charles Darwin certainly found the zebra’s stripes to be a conundrum. In The Descent of Man, he dismissed the idea they could act as camouflage, citing William Burchell’s observations of a herd:

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My Comments: It apparently all comes down to biting flies not liking stripes.

Is Warm Weather Key To Evolution?

An illustration of Neanderthals at the cave site of Trou Al'wesse in Belgium, clinging on as the climate deteriorated. Credit: Digital Painting by James Ives

Warm Sanctuaries Key To Human Evolution -- Cosmos

DUBLIN: Modern and ancient humans withdrew to milder sanctuaries during the Ice Ages in Europe and Asia, and these refuges became critical for human evolution, according to a new study.

New models published in a paper in Science today suggest that refugia - locations that harbour relict populations of a once-widespread species - were important in determining the pace and pattern of the massive human migration from Africa, which began approximately 100,000 years ago.

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My Comment: I live in Canada .... and trust me .... when it comes to winter I am always asking myself on why am I here. So did early man think the same way? Hmmmm .... that appears to be the case.

Are We Becoming More Stupid? Human Brain Has Been 'Shrinking For The Last 20,000 Years'

Old big head: A 3D image replica of a 28,000-year-old skull found in France shows it was 20 per cent larger than ours

From The Daily Mail:

It's not something we'd like to admit, but it seems the human race may actually be becoming increasingly dumb.

Man's brain has been gradually shrinking over the last 20,000 years, according to a new report.

This decrease in size follows two million years during which the human cranium steadily grew in size, and it's happened all over the world, to both sexes and every race.

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My Comment: Are we devolving?

How The Human Brain Got Bigger By Accident And Not Through Evolution

Colin Blakemore believes the human brain became bigger through genetic accident and not evolution. Photograph: David Hartley / Rex Features

From The Guardian:

Oxford neurobiologist Colin Blakemore tells Robin McKie why he thinks a mutation in the human brain 200,000 years ago suddenly made us a super-intelligent species.

According to Woody Allen, it is his second favourite organ and it absorbs more than 25% of the energy that our bodies generate. But why? For what purposes did the human brain evolve and why does it take so much of our physiological resources?

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Intelligent Men 'Less Likely To Cheat'

Revenge of the Nerds

From The Telegraph:

Intelligent men are less likely to cheat on their wives because of evolution, a new analysis of social trends indicates.

Researchers at a British university found that men with higher IQs place greater value on monogamy and sexual exclusivity than their less intelligent peers.

But the connection between conventional sexual morality and intelligence is not mirrored in women, it seems.

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Life-Like Evolution In A Test Tube

With colleague Tracey Lincoln, Gerald Joyce (picured) has created an artificial genetic system that can undergo self-sustained replication and evolution. Credit: Scripps Research Institute

From Cosmos:

SAN DIEGO: Can life arise from nothing but a chaotic assortment of basic molecules? The answer is a lot closer following a series of ingenious experiments that have shown evolution at work in non-living molecules.

For the first time, scientists have synthesized RNA enzymes – ribonucleic acid enzymes also known as ribozymes - that can replicate themselves without the help of any proteins or other cellular components.

What’s more, these simple nucleic acids can act as catalysts and continue the process indefinitely.

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Evolution On The March

From Philadelphia Inquirer:

New DNA findings show that human genetic mutations are more recent, more rapid than once thought.

Conventional wisdom holds that if you could bring back someone from 40,000 years ago, he or she would blend perfectly well with today's population.

After all, the fossils show that our ancestors were "anatomically modern" by 100,000 years ago, and by 40,000 B.C., they were creating complex tools and art.

It was easy to assume our species hadn't evolved much since then.

Now molecular biology is overturning that assumption.

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Feet Hold The Key To Human Hand Evolution

Scientists simulated the change from an ape-like hand to a human-like hand.

From The BBC:

Scientists may have solved the mystery of how human hands became nimble enough to make and manipulate stone tools.

The team reports in the journal Evolution that changes in our hands and fingers were a side-effect of changes in the shape of our feet.

This, they say, shows that the capacity to stand and walk on two feet is intrinsically linked to the emergence of stone tool technology.

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Male Chromosome Evolving Fastest, Study Shows

A scanning probe microscope image of human chromosomes.

From The Telegraph:

The Y chromosome is evolving far faster than the rest of the human genetic code, according to a study by scientists in America.

The research compared the Y chromosomes - which determine a man’s sex - from humans and chimpanzees, man’s nearest living relatives, and showed that they are about 30 per cent different.

That is far greater than the two per cent difference between the rest of the human genetic code and that of the chimpanzee’s. The changes occurred in the last six million years or so, relatively recently when it comes to evolution.

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Ongoing Human Evolution Could Explain Recent Rise In Certain Disorders

New research suggests that certain adaptations that once benefited humans may now be helping such ailments persist in spite of -- or perhaps because of -- advancements in modern culture and medicine. (Credit: iStockphoto/Mads Abildgaard)

From Science Daily:

Science Daily (Jan. 11, 2010) — The subtle but ongoing pressures of human evolution could explain the seeming rise of disorders such as autism, autoimmune diseases, and reproductive cancers, researchers write in the Proceedings of the National Academy of Sciences. Certain adaptations that once benefited humans may now be helping such ailments persist in spite of -- or perhaps because of -- advancements in modern culture and medicine.

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What Came First In The Origin Of Life? New Study Contradicts the 'Metabolism First' Hypothesis

Image of what would be a "compound genome". Different molecules (in various colours) join the globule or corpuscle, which divides once it reaches a critical size. (Credit: Image provided by Doron Lancet)

From Science Daily:

Science Daily (Jan. 9, 2010) — A new study published in Proceedings of National Academy of Sciences rejects the theory that the origin of life stems from a system of self-catalytic molecules capable of experiencing Darwinian evolution without the need of RNA or DNA and their replication.

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Coral Reefs Are Evolution Hotspot

The reefs are centres of evolution as well as biodiversity.

From The BBC:

Coral reefs give rise to many more new species than other tropical marine habitats, according to a new study.

Scientists used fossil records stretching back 540 million years to work out the evolution rate at reefs.

They report in the journal Science that new species originate 50% faster in coral reefs than in other habitats.

The team says its findings show that the loss of these evolution hotspots could mean "losing an opportunity to create new species" in the future.

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What Happened To The Hominids Who Were Smarter Than Us?

A sketched reconstruction if the Boskop skull done in 1918. Shaded areas depict recovered bone. Courtesy the American Museum of Natural History

From Discover Magazine:

The Boskops had big eyes, child-like faces, and an average intelligence of around 150, making them geniuses among Homo sapiens.

In the autumn of 1913, two farmers were arguing about hominid skull fragments they had uncovered while digging a drainage ditch. The location was Boskop, a small town about 200 miles inland from the east coast of South Africa.

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Shopping Styles Of Men And Women All Down To Evolution, Claim Scientists

From The Telegraph:

The reason women love to spend hours browsing in shops while men prefer to be in and out of the high street in minutes is down to their hunter-gathering past, claim scientists.

Differing roles in prehistoric times have evolved into differing shopping styles, the researchers believe.

While women spent their days gathering food often with children, men were hunters who made specific plans about how to catch and kill their prey.

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FUTURE HUMANS: Four Ways We May, Or May Not, Evolve

Looking backward, evolutionary theory—popularized by Charles Darwin's On the Origin of Species, published in 1859—has traced humanity's roots to fossil apes. Now, 150 years later, scientists are looking forward and seeing a range of evolutionary futures for humans. Will our descendants be muscle-bound cyborgs? Electronic immortals? Or is human evolution dead? Photograph by Rebecca Hale, NGS

From National Geographic:

But where is evolution taking us? Will our descendants hurtle through space as relatively unchanged as the humans on the starship Enterprise? Will they be muscle-bound cyborgs? Or will they chose to digitize their consciousnesses—becoming electronic immortals?

And as odd as the possibilities may seem, it's worth remembering that, 150 years ago, the ape-to-human scenario in On the Origin of Species struck many as nothing so much as monkey business.

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Lost: Darwin's Missing Notebook

Charles Darwin Photo: PA

From The Telegraph:

An appeal has been launched to track down one of Charles Darwin's most important notebooks, which was probably stolen in the early 1980s.

English Heritage wants anyone who might know of the whereabouts of Darwin's 'Galapagos notebook' to come forward.

It is launching the appeal today to coincide with the 150th anniversary of the publication of On the Origin of Species.

To mark the anniversary, English Heritage is also publishing online Darwin's 14 other notebooks from his time aboard HMS Beagle between 1831 and 1836.

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The Future of Evolution: What Will We Become?

Could humans split into two species? Perhaps, if we engineer one or if a colony is isolated in outer space. Image credit: stockxpert

From Live Science:

Editor's Note: This is the last in a 10-part LiveScience series on the origin, evolution and future of the human species and the mysteries that remain to be solved.

The past of human evolution is more and more coming to light as scientists uncover a trove of fossils and genetic knowledge. But where might the future of human evolution go?

There are plenty of signs that humans are still evolving. However, whether humans develop along the lines portrayed by hackneyed science fiction is doubtful.

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Humans Still Evolving As Our Brains Shrink

Weighing in at an average of 2.7 pounds (1,200 grams), the human brain packs a whopping 100 billion neurons. Every minute, about three soda-cans worth of blood flow through the brain. Credit: dreamstime.

From Live Science:

Evolution in humans is commonly thought to have essentially stopped in recent times. But there are plenty of examples that the human race is still evolving, including our brains, and there are even signs that our evolution may be accelerating.

Shrinking brains

Comprehensive scans of the human genome reveal that hundreds of our genes show evidence of changes during the past 10,000 years of human evolution.

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How The Elephant Got Its Trunk (And Other Wonders Of Nature)

'No one has ever really known how the elephant got its trunk, or how the leopard got its spots. This project will lay the foundation for work that will answer those questions and many others,' says Dr David Haussler

From The Independent:

Nobel laureate to reveal secrets of evolution via massive gene-mapping project.

An ambitious plan to map the genomes of 10,000 species of vertebrates – animals with backbones – has been announced by scientists.

Unravelling the DNA sequences of the many species of vertebrates will help science to explain how the leopard got its spots, how the elephant came by its trunk and how the bat learned to fly, the researchers said.

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Speed Limit To The Pace Of Evolution, Biologists Say

E. coli growing in a petri dish. (Credit: iStockphoto/Linde Stewart)

From Science Daily:

Science Daily (Nov. 3, 2009) — Researchers at the University of Pennsylvania have developed a theoretical model that informs the understanding of evolution and determines how quickly an organism will evolve using a catalogue of "evolutionary speed limits." The model provides quantitative predictions for the speed of evolution on various "fitness landscapes," the dynamic and varied conditions under which bacteria, viruses and even humans adapt.

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