Category Archives: Evolution

What does 7 Billion People Mean?

Making Sense of 7 Billion People | Wired Science | Wired.com.

  • Follow @9brandon

On the last day of October 2011, the global population of an upstart branch of the primate order will reach 7 billion.review smartphone android

What does it mean?

In itself, not much: Seven billion is just a one-digit flicker from 6,999,999,999. But the number carries a deep existential weight, symbolizing themes central to humanity’s relationship with the rest of life on Earth.

For context, let’s consider a few other numbers. The first: 10,000. That’s approximately how many Homo sapiens existed 200,000 years ago, the date at which scientists mark the divergence of our species from the rest of Homo genus, of which we are the sole survivors.

From those humble origins, humans — thanks to our smarts, long-distance running skills, verbal ability and skill with plants — proliferated at an almost inconceivable rate.

 

Some may note that, in a big-picture biological sense, humanity has rivals: In total biomass, ants weigh as much as we do, oceanic krill weigh more than both of us combined, and bacteria dwarf us all. Those are interesting factoids, but they belie a larger point.

We are the .00018 percent, and we use 20 percent.

Ants and krill and bacteria occupy an entirely different ecological level. A more appropriate comparison can be made between humans and other apex predators, which is precisely the ecological role humans evolved to play, and which — beneath our civilized veneer — we still are.

According to a back-of-the-envelope calculation, there are about 1.7 million other top-level, land-dwelling, mammalian predators on Earth. Put another way: For every non-human mammal sharing our niche, there are more than 4,000 of us.

In short, humans are Earth’s great omnivore, and our omnivorous nature can only be understood at global scales. Scientists estimate that 83 percent of the terrestrial biosphere is under direct human influence. Crops cover some 12 percent of Earth’s land surface, and account for more than one-third of terrestrial biomass. One-third of all available fresh water is diverted to human use.

Altogether, roughly 20 percent of Earth’s net terrestrial primary production, the sheer volume of life produced on land on this planet every year, is harvested for human purposes — and, to return to the comparative factoids, it’s all for a species that accounts for .00018 percent of Earth’s non-marine biomass.

We are the .00018 percent, and we use 20 percent. The purpose of that number isn’t to induce guilt, or blame humanity. The point of that number is perspective. At this snapshot in life’s history, at — per the insights of James C. Rettie, who imagined life on Earth as a yearlong movie — a few minutes after 11:45 p.m. on December 31, we are big. Very big.

However, it must be noted that, as we’ve become big, much of life had to get out of the way. When modern Homo sapiens started scrambling out of East Africa, the average extinction rate of other mammals was, in scientific terms, one per million species years. It’s 100 times that now, a number that threatens to make non-human life on Earth collapse.

In regard to that number, environmentalists usually say that humanity’s fate depends on the life around us. That’s debatable. Humans are adaptable and perfectly capable of living in squalor, without clean air or clean water or birds in the trees. If not, there wouldn’t be 7 billion of us. Conservation is a moral question, and probably not a utilitarian imperative.

But the fact remains that, for all of humanity to experience a material standard of living now enjoyed by a tiny fraction, we’d need four more Earths. It’s just not possible. And that, in the end, is the significance of 7 billion. It’s a challenge.

In just a few minutes of evolutionary time, humanity has become a force to be measured in terms of the entirety of life itself. How do we, the God species, want to live? For the answer, check back at 8 billion.

Warming oceans cause largest movement of marine species in 2m years

Warming oceans cause largest movement of marine species in two million years – Telegraph.

Swarms of venomous jelly fish and poisonous algae are migrating into British waters due to changes in the ocean temperatures, a major new study has revealed.

Warming oceans causing largest movement of marine species in two million years

Image 1 of 2
The venomous warm-water species Pelagia noctiluca  Photo: ALAMY
A Pacific grey whale was sighted in the Meditteranean after swimming through a passage that melted in the Arctic sea ice

Image 2 of 2

A Pacific grey whale was sighted in the Mediterranean after swimming through a passage that melted in the Arctic sea ice

Warming ocean waters are causing the largest movement of marine species seen on Earth in more than two million years, according to scientists.

In the Arctic, melting sea ice during recent summers has allowed a passage to open up from the Pacific ocean into the North Atlantic, allowing plankton, fish and even whales to into the Atlantic Ocean from the Pacific.

The discovery has sparked fears delicate marine food webs could be unbalanced and lead to some species becoming extinct as competition for food between the native species and the invaders stretches resources.

Rising ocean temperatures are also allowing species normally found in warmer sub-tropical regions to into the northeast Atlantic.

A venomous warm-water species Pelagia noctiluca has forced the closure of beaches and is now becoming increasingly common in the waters around Britain.

The highly venomous Portuguese Man-of-War, which is normally found in subtropical waters, is also regularly been found in the northern Atlantic waters.

A form of algae known as dinoflagellates has also been found to be moving eastwards across the Atlantic towards Scandinavia and the North Sea.

Huge blooms of these marine plants use up the oxygen in the water and can produce toxic compounds that make shellfish poisonous.

Plankton sampling in the north Atlantic over the past 70 years have also shown that other species of plankton, normally only found in the Pacific ocean, have now become common in Atlantic waters.

The scientists, who have been collaborating on the Climate Change and European Marine Ecosystems Research project, found the plankton species, called Neodenticula seminae, traveled into the Atlantic through a passage through the Arctic sea ice around that has opened up a number of times in the last decade from the Pacific Ocean.

Larger species including a grey whale have also been found to have made the journey through the passage, which winds it’s way from the Pacific coast of Alaska through the islands of northern Canada and down past Greenland into the Atlantic Ocean, when it opened first in 1998, and then again in 2007 and 2010.

Professor Chris Reid, from the Sir Alister Hardy Foundation for Ocean Science at the Plymouth Marine Laboratory, said: “It seems for the first time in probably thousands of years a huge area of sea water opened up between Alaska and the west of Greenland, allowing a huge transfer of water and species between the two oceans.

“The opening of this passage allowed the wind to drive a current through this passage and the water warmed up making it favourable for species to get through.

“In 1999 we discovered a species in the north west Atlantic that we hadn’t seen before, but we know from surveys in the north Pacific that it is very abundant there.

“This species died out in the Atlantic around 800,000 years ago due to glaciation that changed the conditions it needed to survive.

“The implications are huge. The last time there was an incursion of species from the Pacific into the Atlantic was around two to three million years ago.

“Large numbers of species were introduced from the Pacific and made large numbers of local Atlantic species extinct.

“The impact on salmon and other fish resources could be very dramatic. The indications are that as the ice is continuing to melt in the summer months, climate change could lead to complete melting within 20 to 30 years, which would see huge numbers of species migrating.

“It could have impacts all the way down to the British Isles and down the east coast of the United States.”

He added: “With the jellyfish we are seeing them move further north from tropical and subtropical regions as a result of warming sea temperatures.”

Researchers say the invading plankton species is likely to cause widespread changes to the food web in the Atlantic ocean as the invading species are less nutritious than native species, which are eaten by many fish and large whales.

Changes in populations of tiny animals called copepods, which are an essential food source for fish such as cod, herring and mackerel, are already being blamed for helping to drive the collapse of fish stocks as the native species of copepods have been replaced with smaller less nutritious varieties.

This has resulted in declines in North Sea birds, the researchers claim, while Harbour porpoises have also migrated northwards North Sea after sand eels followed the poleward movement of the copepods they ate.

Scientists taking part in the project from the Institute for Marine Resources & Ecosystem Studies, in the Netherlands, found that warmer water would also lead more species in the North and Irish sea as species move from more southerly areas.

But they found that the Atlantic ocean west of Scotland would have fewer species.

Dr Carlo Heip, director general of the Royal Netherlands Institute for Sea Research, which led the project that is a collaboration of more than 17 institutes in 10 different countries, said: “We need to learn much more about what’s happening in Europe’s seas, but the signs already point to far more trouble than benefit from climate change.

“Despite the many unknowns, it’s obvious that we can expect damaging upheaval as we overturn the workings of a system that’s so complex and important.

“The migrations are an example of how changing climate conditions cause species to move or change their behaviour, leading to shifts in ecosystems that are clearly visible.”

The researchers conclude that these changes will have serious implications for commercial fisheries and on the marine environment.

Among the other species to have migrated from the Pacific Ocean into the Atlantic was a grey whale that was spotted as far south as the Mediterrean off the coast of Spain and Israel.

Grey whales have been extinct in the Atlantic Ocean for more than a hundred years due to hunting and scientists found the animal had crossed through openings in the Arctic sea ice.

Dr Katja Philippart, from the Royal Netherland’s Institute for Sea Research, added: “We have seen very small plankton and large whales migrating from the Pacific into the North Atlantic, so there will certainly be many other species, including fish, that we haven’t detected yet.

“To see a whale in this part of the world was quite remarkable and when we looked at it we concluded it can only have come from one place.”

Climate change may alter conditions for growth of oak trees in Basque woodlands

Climate change may alter conditions for growth of oak trees in Basque woodlands.

ScienceDaily (July 8, 2011) — Neiker-Tecnalia has carried out a study on trends in the future distribution of habitats of Basque woodlands, pointing out that climate change may alter the conditions necessary for the growth of a tree as representative of the Basque lands as the oak.

The research was undertaken on the basis of the most pessimistic and severe scenarios for conditions of climate change in the future and claims that for 2080, the oak woods of the Basque Country would undergo a significant or almost total reduction of their habitat, given that, in our territory, wooded areas will not meet the variables of temperature and humidity necessary for their development. Neiker-Tecnalia experts consider that this study illustrates the tendency towards the ‘Mediterraneanisation” of woods in Euskadi.

The technological centre is analysing this possible impact of climate change on the distribution of the habitat of forestry species, within the K-Egokitzen and Adaptaclima projects, financed by the Basque Government and the European Union (Interreg IVB SUDOE) respectively. One of the end goals of both projects involved drawing up methodologies in order to help understand how the forestry habitats will be in a short and a long term. In the conclusions from the Neiker-Tecnalia specialists, it is seen that the oak will find favourable conditions for its development in increasingly higher latitudes as time passes.

Based on the results, and assuming the capacity for dispersion of the oak allows it, it is conceivable that it may be a tendency for migration of oak woods towards the north of Europe. Nevertheless, they would keep its own natural habitat in the Basque Country until 2080, a time when it has been predicted they would undergo a significant or almost total reduction of the species´ habitat. This phenomenon could result in the oak by that year, while still having a great adaptative capacity to the predicted climate change, meeting with a threshold of conditions in which it cannot maintain its population.

The study shows that the oak would lose out potential habitat to make way for other Mediterranean species, such as the cork. Other trees, such as the pyrenean oak, present in the Basque territory, would maintain their populations as they are adapted to the climatic conditions of the Mediterranean region.

The predictions for the cork provide one of the clearest examples of the ‘Mediterraneanisation’ of the Atlantic part of the Iberian Península. Despite being a typically Mediterranean species, in Euskadi could be adecuate conditions for their development throughout the eighties of this century.

Those conclusions do not mean that Mediterranean species will substitute the species that nowadays exist in the Basque Country, since, this study has been carried out using statistical models whose results do not show where the species will be found, but where similar relation of current climate conditions for the species will be given in the future. Besides, the real distribution of one species is determined by an infinite number of factors that statistical models do not take into consideration, such as species competition, dispersion ability or the adaptation ability to climate changes.

To undertake the research on trends in the evolution of the habitat, scientists took into account a total of 19 bioclimatic variables, amongst which were the annual mean temperature, the maximum temperature of the hottest quarter, minimum temperature of the coldest, annual precipitation and the rainfall in the wettest and driest quarters. The conclusions, thus, of this research, should be complemented in the future with new variables which, as with the bioclimatic ones, affect the distribution of tree species.

New monkey found in Myanmar near China dam project

New monkey found in Myanmar near China dam project | Reuters.

That’s one ugly monkey.

(Reuters) – A new type of snub-nosed monkey has been found in a remote forested region of northern Myanmar which is under threat from logging and a Chinese dam project, scientists said on Wednesday.

They said hunters in Myanmar’s Kachin state said the long-tailed black monkey, with white-tufted ears and a white beard, could often be tracked in the rain because its upturned nostrils made it prone to sneezing when water dripped in.

“It’s new to science. It’s unusual to travel to a remote area and discover a monkey that looks unlike any other in the world,” Thomas Geissmann, lead author of the study at the University of Zurich-Irchel, told Reuters.

Studies of a carcass and four skulls showed the monkey differed from snub-nosed monkeys in China and Vietnam. The experts had no photos of a live Myanmar monkey.

The scientists estimated there were between 260 and 330 of the monkeys living in an area of about 270 sq km (100 sq miles) and believed the species to be critically endangered.

“The hunting pressure is likely to increase considerably in the next few years as new dam construction and logging roads invade” the monkeys’ habitat, they wrote in the American Journal of Primatology.

IN CHINESE HANDS

“The future of the snub-nosed monkey lies in Chinese hands,” said Frank Momberg, of Fauna and Flora International and a co-author of the study. Monkeys were hunted for meat or fur and their body parts were used in traditional medicines in China.

He said China Power Investment Corp., leading the dam project further down the valley on a tributary of the Irrawaddy River in Myanmar, had an economic interest in preserving the forested region where the monkeys live.

More roads and logging would cause erosion around the watershed that could clog up the new reservoir with silt, reducing power generation, he said. He praised China for carrying out a study of the dam’s possible effect on the environment.

The discovery of the snub-nosed monkey contrasts with a rising trend of extinctions, caused by factors such as land clearance, expansion of cities, pollution and climate change.

A U.N. conference in Nagoya, Japan, this week is looking at ways to safeguard biological diversity after the world failed in a goal set in 2002 of a “significant reduction” in the pace of extinctions of animals and plants by 2010.

A separate study in the journal Science showed growing numbers of the world’s birds, mammals and amphibians had moved closer to extinction in recent decades. A fifth were classified as threatened.

For Reuters latest environment blogs, click on: blogs.reuters.com/environment/

20% of world's plants at risk of extinction

BBC News – One-fifth of world’s plants at risk of extinction.

Artemisia annua plant Plants such as artemisia sweet wormwood provide valuable drugs – in this case, for malaria

One-fifth of the world’s plants – the foundation of life on Earth – are at risk of extinction, a study concludes.

Researchers have sampled almost 4,000 species, and conclude that 22% should be classified as “threatened” – the same alarming rate as for mammals.

A further 33% of species were too poorly understood to be assessed.

The analysis comes from the Royal Botanic Gardens at Kew, the Natural History Museum and International Union for the Conservation of Nature (IUCN).

There are an estimated 380,000 plant species in all, and many are victims of habitat loss – typically the clearing of forests for agriculture.

Species in tropical rainforests are found to be at greatest risk.

The study, known as the Sampled Red List Index for Plants, is an attempt to provide the most accurate assessment so far.

Start Quote

Plants are the basis of all life on Earth, providing clean air, water, food and fuel”

End Quote Stephen Hopper RBG Kew

Previous studies have focused on the most threatened plants or particular regions.

This one instead sampled species from each of the five main groups of plants, and its authors argue that as a result, their conclusions are more credible.

The report comes ahead of the UN Biodiversity Conference in Nagoya in Japan next month where ministers are due to discuss why conservation targets keep being missed.

Click to play

David Shukman visited the freezing seed bank at Kew’s Botanical Gardens

Launching the findings, Kew’s director, Professor Stephen Hopper, said the study would provide a baseline from which to judge future losses.

“We cannot sit back and watch plant species disappear – plants are the basis of all life on Earth, providing clean air, water, food and fuel.

“Every breath we take involves interacting with plants. They’re what we all depend on.”

Medicinal properties

The study investigated the key types of plants, including mosses, ferns, orchids and legumes like peas and beans.

The fear among botanists is that species are being wiped out before they can be researched, potentially losing valuable medicinal properties.

Plant-based remedies are the only source of healthcare in the world’s poorest countries, and have proved essential in combating conditions including malaria and leukaemia.

Samples in freezer Seed and tissue banking is now a key conservation tool

Another concern is that we have become dependent on a narrow range of plants with a limited genetic base.

The report estimates that 80% of the calories consumed worldwide are derived from just 12 different species.

The findings add urgency to the work of Kew’s Millennium Seed Bank at Wakehurst in Sussex, which has now gathered some 1.8 billion seeds from around the world.

The samples are catalogued and stored in underground cold rooms as a safeguard against future losses.

The collection includes seeds from plants that have already been judged extinct, including a species of tree from Pakistan and an orchid from Ecuador.

Another victim is a species of olive tree from the South Atlantic island of St Helena.

The only traces of its existence are a few dried pressings of its leaves, and a tiny sample of DNA kept in a plastic test-tube in a freezer.

Mass Extinctions Change the Rules of Evolution

Mass Extinctions Change the Rules of Evolution | Wired Science | Wired.com.

ANOTHER giant ‘DUH’ for science: mass extinctions make things happen differently thereafter.

A reinterpretation of the fossil record suggests a new answer to one of evolution’s existential questions: whether global mass extinctions are just short-term diversions in life’s preordained course, or send life careening down wholly new paths.

Some scientists have suggested the former. Rates of species diversification — the speed at which groups adapt and fill open ecological niches — seemed to predict what’s flourished in the aftermath of past planetary cataclysms. But according to the calculations of Macquarie University paleobiologist John Alroy, that’s just not the case.

“Mass extinction fundamentally changes the dynamics. It changes the composition of the biosphere forever. You can’t simply predict the winners and losers from what groups have done before,” he said.

Alroy was once a student of paleontologist Jack Sepkoski, who in the 1980s formalized the notion that Earth has experienced five mass extinctions in the 550 million years since life became durable enough to leave a fossil record. Graphs of taxonomic abundance depict lines rising steadily as life diversifies, plunging precipitously during each extinction, and rising again as life proliferates anew.

As the fossil record is patchy and long-term evolutionary principles still debated, paleobiologists have historically disagreed about what these extinctions mean. Some held that, in the absence of extinctions, species would diversify endlessly. The Tree of Life could sprout new branches forever. Others argued that each taxonomic group had limits; once it reached a certain size, each branch would stop growing.

Sepkoski’s calculations put him on the limits side of this argument. He also proposed that, by looking at the rate at which each group produced new species, one could predict the winners and losers of each mass extinction’s aftermath. Groups that diversified rapidly would flourish. Their destiny was already established.

“It’s a clockmaker vision of evolution. Each group has fixed dynamics, and if there’s an extinction, it just messes it up a bit,” said Alroy. “That’s what I’m challenging in this paper. There are limits, and that’s why we don’t have a trillion species. But those limits can change.”

Alroy crunched marine fossil data in the Paleobiology Database, which gathers specimen records from nearly 100,000 fossil collections around the world. He used a statistical adjustment method designed to reduce the skewing influences of paleontological circumstance — the greater chances of finding young fossils rather than old, the ease of studying some types of rock rather than others.

Historical species diversity among marine animals of Cambrian, Paleozoic and Modern origin.

The analysis, published September 2 in Science, produced what Alroy considers to be the most accurate reflection of extinction dynamics to date. And while his data supported the notion that each group’s diversity eventually hits a limit, he didn’t find Sepkoski’s correlation between pre-mass-extinction diversity rates and post-extinction success. Each mass extinction event seemed to change the rules. Past didn’t indicate future.

In an accompanying commentary, paleontologist Charles Marshall of the University of California, Berkeley noted that Alroy’s statistical methods still need review by the paleobiology community. The Paleobiological Database, for all its thoroughness, might also be incomplete in as-yet-unappreciated ways. “There will be no immediate consensus on the details of the pattern of diversity,” he wrote. But “the pieces are falling into place.”

Enough pieces have come together for Alroy to speculate on his findings’ implication for the future, given that Earth is now experiencing another mass extinction. Starting with extinctions of large land animals more than 50,000 years ago that continued as modern humans proliferated around the globe, and picking up pace in the Agricultural and Industrial ages, current extinction rates are far beyond levels capable of unraveling entire food webs in coming centuries. Ecologists estimate that between 50 and 90 percent of all species are doomed without profound changes in human resource use.

In the past, many evolutionary biologists thought life would eventually recover its present composition, said Alroy. In 100 million years or so, the same general creatures would again roam the Earth. “But that isn’t in the data,” he said.

Instead Alroy’s analysis suggests that the future is inherently unpredictable, that what comes next can’t be extrapolated from what is measured now, no more than a mid-Cretaceous observer could have guessed that a few tiny rodents would someday occupy every ecological niche then ruled by reptiles.

“The current mass extinction is not going to simply put things out of whack for a while, and then things will go back to where we started, or would have gone anyway,” said Alroy. Mass extinction “changes the rules of evolution.”

Images: 1) A fossil skull of Dunkleosteus, an apex predator fish that lived between 380 million and 360 million years ago, and had what is believed to be history’s most powerful bite./Michael LaBarbera, courtesy of The Field Museum. 2) Graph of species diversity among marine animals of Cambrian, Paleozoic and Modern origin./Science.

Read More http://www.wired.com/wiredscience/2010/09/mass-extinction-dynamics/#ixzz0yPE4fDQc

Critical Ocean Organisms Are Disappearing – ScienceNOW

This is totally messed up! We are sooooo screwed!

Original Article form ScienceNOW

The number of marine phytoplankton, the microscopic organisms that gobble greenhouse gases and directly or indirectly feed every animal in the ocean, has been declining by about 1% per year, according to a new study. If the trend continues, it could decimate ocean food chains and accelerate global warming.

Researchers know that phytoplankton numbers have been dropping for the past 30 years. Satellite images show a decline in the concentration of chlorophyll—a green pigment that helps phytoplankton photosynthesize. But because satellites have been collecting data only since the late 1970s, scientists couldn’t determine whether this drop was a long-term trend or just a fluke.

To get a more comprehensive record of phytoplankton numbers, Boris Worm of Dalhousie University in Halifax, Canada, and colleagues dug into old shipboard records from sailors who had studied the ocean as far back as 1900. In those days, sailors used a tool called a Secchi disk to gauge how clear the ocean was. They weren’t trying to measure phytoplankton, but they inadvertently did because chlorophyll clouds the water.

When Worm and colleagues combined the satellite data, the early shipboard records, and direct measurements of chlorophyll made from the 1950s onward, they found that the recent dip in phytoplankton wasn’t a passing phase. It had been happening in most parts of the ocean for more than a century. On average, the planet has lost 1% of its phytoplankton every year since 1900, the team reports in the 29 July issue of Nature.

“You compound that over a century, this becomes a huge, huge decline,” says Paul Falkowski, an oceanographer at Rutgers University in New Brunswick, New Jersey, who was not part of the study. Indeed, Worm’s team estimates that phytoplankton numbers have plummeted 40% since 1950.

What’s more, the team found that phytoplankton numbers were more likely to dwindle in areas of the ocean that were warming, suggesting that climate change is responsible for the drop.

The loss of phytoplankton is a huge problem for marine food chains, says Worm, because every creature in the ocean either eats phytoplankton or eats other organisms that depend on it. If their numbers start to decrease, the populations of these species would drop as well. “The rest of the food web would basically contract,” he says.

Even more chilling to marine biologist Anthony Richardson of the University of Queensland in Australia is the potential impact on our atmosphere. The ocean absorbs 40% of the CO2 humans emit. Phytoplankton, in turn, convert that CO2 into oxygen or die and bury it at the bottom of the ocean. If the phytoplankton are disappearing, Richardson says, “the ocean as a carbon sink is declining, and what that means is ultimately more CO2 will stay in the atmosphere instead of being dissolved in the ocean.” That will translate into a warmer world, which will wipe out even more phytoplankton.

The study has its drawbacks. The older shipboard data weren’t collected with nearly as much regularity as the satellite data, notes marine biologist Mike Behrenfeld of Oregon State University, Corvallis. Still, marine biologist David Siegel of the University of California, Santa Barbara, says that given the sporadic records, Worm and colleagues have constructed a solid report. “They’ve squeezed as much as possibly can be squeezed out of this data set.”

via Critical Ocean Organisms Are Disappearing – ScienceNOW.