JoNova

A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).


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The Skeptics Handbook II

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Asteroid kills 90% of all mammal species: Anthropocene kills one rat (maybe)

Compare the tallies. Sixty-five million years ago an asteroid smacked-down and only 10% of mammal species survived. So far in the Anthropocene Catastrophe, one type of rat has been wiped off a 300m island.

Press Release Mammals almost wiped out with the dinosaurs

A study by researchers at the Milner Centre for Evolution at the University of Bath and published in the Journal of Evolutionary Biology, reviewed all mammal species known from the end of the Cretaceous period in North America. Their results showed that over 93 per cent became extinct across the Cretaceous-Paleogene (K-Pg) boundary, but that they also recovered far more quickly than previously thought.

Afterwards, mammalian life recovered with unexpected speed and diversity. Chalk one up to nature and evolution. Not so fragile?

[...]

Life copes: The horses that adapted to massive climate change in just 800 years

In evolutionary terms, it’s a blink. Around 1200-1400AD a bunch of people bought a few domestic horses to far east freezing Siberia, where the temperature sometimes falls below -70. Somehow the horses have already become physiologically and genetically well adapted to the extreme climate. The panic-merchants would have us believe that the climate is changing “faster than evolution”, but biology and genes turn out to be amazingly flexible. (Who knows, maybe 4 million years of swinging ice ages has that effect on gene pools?)

DNA studies revealed that these horses were all derived from distant domestic horses, even though wild unrelated horses lived in the region til 5,000 years ago. This is pretty spectacular.

Dr. Ludovic Orlando: “This is truly amazing as it implies that all traits now seen in Yakutian horses are the product of very fast adaptive processes, taking place in about 800 years. This represents about a hundred generations for horses. That shows how fast evolution can go when selective pressures for survival are as strong as in the extreme environment of Yakutia.”

Analyzing the genomes shows that it’s not driven by mutations in genes as much as by changes to the regulatory [...]

Lo! Shark god protects us from storms, floods, heatwaves (sayth Nature & ABC)

Big news: A new endogenous forcing found for climate change — sharks. For millions of years you thought predator-prey relationships were just about big fish having dinner, but not so, they are climate forcings. Sharks cool the planet, and stop storms, floods, droughts and malaria. Crabs, on the other hand, pollute like a coal company. It’s a miracle that the planet made it through the last billion years without the EPA managing the  shark-crab numbers thing. This ABC interview inspired me to channel the spirit of neolithic science.

The dusken-shark doth smite the naughty fishies and give us nice weather

New research has found that sharks play an important role in preventing climate change, warning that overfishing and culling sharks is resulting in more carbon being released from the seafloor.

“Sharks, believe it or not, are helping to prevent climate change,” said Dr Peter Macreadie, an Australian Research Council Fellow from Deakin University and one of the paper’s authors.

Sharks: Good.  Crabs and Turtles: Bad.  Kill those turtles!

“Turtles, crabs, certain types of worms, stingrays — these animals that are overabundant to do with loss of predators used to keep their numbers in check,” [...]

Life on Earth more adaptable than models predict

Potato Beetle

Researchers predicted a particular beetle would not be able to get into the cold areas of Kazakhstan and western China. But the sneaky beetles learnt to cope with the cold by burying themselves in the ground.  The modelers failed completely to predict the spread. Imagine the ecological modelers who are not only using inadequate biological models, but guesstimating the future temperature with climate models that don’t work either.

In the last 500 million years as life on Earth evolved the temperature has swung up and down through a range of about 15C. We are currently in the cooler half of that temperature range, in a mini-warm-moment surrounded by ice ages. Despite this, the climate-industry is panicking that a half a degree of extra warmth this century will wipe out species that survived the last ten million years.

The potato beetle laughs at them.

Crop pests outwit climate change predictions en route to new destinations Scientists highlight the dangers of relying on climate-based projections of crop pest distribution

[...]

Fossils show models can’t predict how climate affects animals

Fossils show those dang mammals lived in all the spots they weren’t supposed to live in. Climate models don’t predict the climate, and animal distribution models don’t predict (or in this case hindcast) animal distribution either. How little we know, and how adaptable is biology?

This calls into question all the headline prophecies about the extinction of cute furry critters due to climate change.

The modelers were sure that animals would be unable to cope with temperature changes and would not have lived in the same places as they do now during a climate so different. By crikey, it was an ice age!  Yet those small mammals, whose defining biology is that regulate their own temperature, flummoxed the models by living nearer the glacier sheets where the models predicted they would not live.

All the alarming forecasts of local extinctions of mammals come from assumptions built into modern models that fail in multiple ways. The temperature changes from the last 20,000 years show that these mammals have already survived massive shifts, both colder and warmer, and that anything we face in the next century is but a flea on a hippo.

In the graph, the dots are the fossils, the [...]

Salmon quite happy to adapt to warmer world

You will never guess, but salmon that survived the hot Holocene period, and the even hotter Eemian, will probably be OK in a slightly warmer world. Expert researchers found this surprising.

Given the broad spread of Salmon in the Northern Hemisphere, and their past survival through every single interglacial warm period of the Pleistocene, I would have thought that they could cope with quite a bit of  climate change. As it turns out, they cope so well, that even salmon eggs that come from a 12C environment can be raised in an environment a whopping 8C warmer, and they were not noticeably any worse off.

Part of the concern with salmon was the spawning and eggs, and the problem with getting the salmon to shift their maternity wards and childcare arrangements (which they seem very attached too). But presumably those breeding grounds have varied before in temperature, and salmon didn’t die out, so — at least with this problem — nature has it figured out.

Map: Salmon and Climate Change, Fish in hot water, Red List.

Atlantic salmon also show capacity to adapt to warmer waters

Populations of Atlantic salmon have a surprisingly good capacity to adjust [...]

Whales dive to nearly two miles depth, hold breath for two hours

Friday curiosity: Duck-diving Cuvier’s beaked whales can hold their breath for over two hours, and reach a depth of 2 miles (3.2 km) underwater. What’s more, when they come up, they recover in an unbelievable two minutes. (Actually, I really do find this hard to believe. Two minutes? Seriously? )

Cuvier Beaked Whale | Oceanus Magazine Woods Hole Oceanographic Institution

These whales can go four times deeper than modern nuclear submarines which are estimated to have a hull crush depth of around 730m. Presumably the Department of Defence will be looking into blubber power or nuclear whales.

But seriously, whales and seals can hold their breath for a ridiculously long time because they pack a lot of oxygen away in their muscles — it’s attached to myoglobin which they have in abundance. Myoglobin‘s quite a lot like the haemoglobin molecule found in blood, it uses iron to bind the oxygen.

For a completely useless culinary tip, whale meat is thus the absolute reddest-of-red-meats and very iron rich –  “perfect” then,  for anemic vegetarians.

Scientists monitored Cuvier’s beaked whales’ record-breaking dives to depths of nearly two miles below the ocean surface and some dives lasted for over [...]