Category Archives: Science

Triassic Winged Dinosaurs*

Of all the wondrous dinosaurs, surely the ancient fliers are the most awe inspiring.  At the same time as ancestral birds and close relatives evolved near the ground and up into the air, a whole other group of animals, the pterosaurs and pterodactyls soared over the heads of the dinosaurs.

Some of the largest animals ever to fly, they must have been awesome to see.

This summer a group from the US reports a new find, a pterosaur fossil from Utah [1].  With a 1.5 m wingspan, this find is significantly earlier (late Triassic, circa 200 million years ago—long before the classic dinosaurs species we all know) than other pterosaurs. It was also found in sandstone from a dry, desert environment, while other finds have been in marine environments in Europe [2].

Artist’s impression of Caelestiventus hanseni (Credit: Michael Skrepnick)

It isn’t difficult to believe that large flying animals could spread to many environments, and also evolve to specialize for, say hunting fish.  So we can see that this family may well have lived in many places, for a long time.  But what we have generally considered the “normal” lifestyle of the pterosaurs—cliff side nesting along shores, eating fish—may well be a successful specialization of a much more diverse family.

Which all goes to show that we need to be very careful about over interpreting the sparse fossil record.  Previous evidence only included marine pterosaurs from much later.  We now know that interpreting this as evidence that the species did not live elsewhere much earlier was incorrect.

* For some, this species is technically not a “dinosaur”. But it’s a large, ancient, school-of dinosaur, so that’s close enough for me.

  1. Brooks B. Britt, Fabio M. Dalla Vecchia, Daniel J. Chure, George F. Engelmann, Michael F. Whiting, and Rodney D. Scheetz, Caelestiventus hanseni gen. et sp. nov. extends the desert-dwelling pterosaur record back 65 million years. Nature Ecology & Evolution, 2018/08/13 2018.
  2. Mary Halton, Winged reptiles thrived before dinosaurs, in BBC News – Science & Environment. 2018.

US Climate Science Special Report

This month David W. Fahey of the US National Oceanic and Atmospheric Administration addressed the American Solar Energy Society Solar 2018 conference in Boulder, CO.  He called attention to the highly authoritative new report, the fourth US National Climate Assessment [1].  Volume 1 is out, Volume 2 will be published later this year.

Fahey explained that this assessment is mandated by Congress, and is a science report, not a policy document. It contains a summary of what we know about climate change (specifically in the US), with an emphasis on careful analysis of the evidence and unknowns.

This is similar in spirit and in results to the IPCC report except only by and about the US.  Fahey was at pains to point out that the report was thoroughly reviewed (seven times!)  and signed off by the US National Academy and by 13 departments and agencies.

He describes this as “us talking to us”.

The report itself is hundreds of pages long, the executive summary alone is 30 some pages.  No, I have not had time to read it.

There is a two page “highlights” that I have read.

For anyone with even the least familiarity with climate science will not be surprised by the findings. The main report backs up these points with the best science available, as well as clear statements about just how good the science is.

The main points are extracted from the report:

This period is now the warmest in the history of modern civilization.

it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century.

Thousands of studies conducted by researchers around the world have documented changes in surface, atmospheric, and oceanic temperatures; melting glaciers; diminishing snow cover; shrinking sea ice; rising sea levels; ocean acidification; and increasing atmospheric water vapor.

global average sea level has risen by about 7–8 inches since 1900, with almost half (about 3 inches) of that rise occurring since 1993

Global sea level rise has already affected the United States; the incidence of daily tidal flooding is accelerating in more than 25 Atlantic and Gulf Coast cities.

Global average sea levels are expected to continue to rise—by at least several inches in the next 15 years and by 1–4 feet by 2100. A rise of as much as 8 feet by 2100 cannot be ruled out.

Heavy rainfall is increasing in intensity and frequency across the United States and globally and is expected to continue to increase.

Heatwaves have become more frequent in the United States since the 1960s, while extreme cold temperatures and cold waves are less frequent.

 over the next few decades (2021–2050), annual average temperatures are expected to rise by about 2.5°F for the United States, relative to the recent past (average from 1976–2005), under all plausible future climate scenarios.

The incidence of large forest fires in the western United States and Alaska has increased since the early 1980s and is projected to further increase

Annual trends toward earlier spring melt and reduced snowpack are already affecting water resources in the western United States

chronic, long-duration hydrological drought is increasingly possible before the end of this century.

The magnitude of climate change beyond the next few decades will depend primarily on the amount of greenhouse gases (especially carbon dioxide) emitted globally.

With significant reductions in emissions, the increase in annual average global temperature could be limited to 3.6°F (2°C) or less.

The global atmospheric carbon dioxide (CO2) concentration has now passed 400 parts per million (ppm), a level that last occurred about 3 million years ago, when both global average temperature and sea level were significantly higher than today. Continued growth in CO2 emissions over this century and beyond would lead to an atmospheric concentration not experienced in tens to hundreds of millions of years. There is broad consensus that the further and the faster the Earth system is pushed towards warming, the greater the risk of unanticipated changes and impacts, some of which are potentially large and irreversible.

In 2014 and 2015, emission growth rates slowed as economic growth became less carbon-intensive. Even if this slowing trend continues, however, it is not yet at a rate that would limit global average temperature change to well below 3.6°F (2°C) above preindustrial levels.

Fahey encourages everyone to read the summary, and to share the report.

Which I am doing here.

  1. Donald J. Wuebbles, David W. Fahey, Kathy A. Hibbard, David J. Dokken, Brooke C. Stewart, and Thomas K. Maycock, Climate Science Special Report: Fourth National Climate Assessment. U.S. Global Change Research Program, Washington, DC, 2017.

Hayabusa2 Asteroid Explorer Is On Station

The JAXA Hayabusa2 (‘Peregrine Falcon’) spacecraft has arrived at its historic rendezvous with the asteroid Ryugu.  The mission plans to remain on station for 18 months, landing on the surface this fall, and then taking off and landing two more times before returning to Earth with samples in 2020.


This spacecraft is a updated version of the first Hayabusa, which retrieved a sample from an asteroid in 2010.  Like several contemporary spacecraft, these explorers have ion engines, which are extremely versatile and capable of long, complicated missions.

The payload includes three tiny rovers to be released, as well as sensors and an “impactor”.  If I understand correctly, the impactor is a cannon that fires a projectile onto the surface, blasting a crater.  Whoa! The lander will then be able to sample the disturbed material.

The target is a peculiar looking rock, with a surprising polygonal shape.

Asteroid Ryugu photographed by the ONC-T on June 24, 2018 at around 00:01 JST. Credit : JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, Aizu University, AIST

The first mission was plagued by technical problems, but this second try should go better.  Fingers crossed.

We’ll be watching.

  1. John Boyd, Space Explorer Hayabusa2 Prepares to Land on a Diamond-Shaped Asteroid 900 Meters Wide, in IEEE Spectrum – Tech Talk. 2018.


Chinese Sauropods Overturn Hyoptheses

Every week there are new dinosaur fossils reported, along with other species and interesting trackways.  It truly is a great age for dinosaur studies.

In recent decades, many new discoveries have come from locations in China, which have not been explored as thoroughly as some other places.  (When I was a young dinosaur enthusiast, China was in turmoil and closed to international scientific collaboration.  That has changed.)

This summer, an international team reports new fossils from the fabulously rich beds of Northwest China which are 7-10 sauropods, tagged Lingwulong I (amazing dragon of Lingwu) , who lived in the Middle Jurassic (more than 17- Mya) [2].  This find is interesting because these sauropods have not been found in Asia, and these fossils are also much older than previous sauropod finds.

The geography and dating suggest that these ancestral sauropods (neosauropods) were widely distributed much earlier than previously thought.  In fact, this find pretty much overturns the common understanding of the evolutionary history of sauropods.

Based on previous fossil finds, it has been thought that sauropods emerged after Pangea broke up, and did not reach East Asia.  This has been attributed to geographical barriers.

Furthermore, these fossils push back the origin of this family of dinosaurs to times before the Pangea continent fully split up.  This calls into question any hypotheses about putative geographical barriers.

“The new discovery challenges conventional biogeographical ideas, and suggests that dispersal into East Asia occurred much earlier than expected. Moreover, the age of this new taxon indicates that many advanced sauropod lineages originated at least 15 million years earlier than previously realised, achieving a global distribution while Pangaea was still a coherent landmass.” ([2], p.1)

It now seems that the absence of sauropods and other species from the fossil record may be due to inadequate sampling in Asia.  Once again, theorizing has be far too confident compared to the actual fossil record.

Clearly, the wonderful finds coming out of China are proving that blank pages in the prehistory of Asia and other poorly sampled areas are not proof of absence.

Keep digging! It’s just starting to get interesting!

Image caption: The dinosaur was excavated in the Lingwu region of China, for which it is named (from [1]) Credit: Xu Xing

  1. Mary Halton, China fossil tells new supercontinent story, in BBC News -Science & Environment. 2018.
  2. Xing Xu, Paul Upchurch, Philip D. Mannion, Paul M. Barrett, Omar R. Regalado-Fernandez, Jinyou Mo, Jinfu Ma, and Hongan Liu, A new Middle Jurassic diplodocoid suggests an earlier dispersal and diversification of sauropod dinosaurs. Nature Communications, 9 (1):2700, 2018/07/24 2018.


Bison Calves in Banff

The great Bison reintroduction continues apace, at least North of the border.

The Bison introduced to Banff last year are set to be released from their initial holding area later this summer.   This event was heralded by the birth of three (and more to come) new calves, “made in Banff” as the Albertans want to say.  The buffalo are back after 140 years, and seem pretty happy and healthy.

Credit: Parks Canada

One goal of this reintroduction is to restore a keystone species to the ecology.  As the Banff Bison Blog explains, in the original wild ecosystem buffalo produced many benefits for other plants and animals, including:

It’s early days, of course, but the project reports that there is already some small impact.

Bison have formed large wallows in the paddock. They’ve rubbed against trees – leaving pieces of fur behind that have been picked up by birds for their nests. They’ve started to carve out trails in the forest. Their dung is providing habitat for insects that then become food for birds and small mammals.

The second goal is to restore the place of buffalo in the indigenous cultures of the area. To this end, humans marked the happy occasion earlier with a private blessing to welcome the buffalo [3]. Whether or not the buffalo felt a need for people to welcome them, it is always good and right to humbly recognizing nature.

I will say for the record that the reintroduction of the buffalo is not just good for the local tribes.  There are many of us who love the buffalo for what they represent, and we are buoyed by the successful reintroduction of this almost lost species in so many places

Welcome, welcome, little ones.

  1. Banff National Park, Bison are Already Changing Banff, in Bison Blog. 2018: Banff.
  2. BBC, Banff National Park welcomes first bison calves in 140 years, in BBC News – US & Canada.
  3. Colette Derworiz, Banff holds blessing ceremony with Indigenous elders before letting bison roam, in CBC News. 2018.
  4. Sarah Rieger, ‘Made-in-Banff’ bison calves born in park’s backcountry for 1st time in more than 140 years, in CBC News. 2018.


PS: “Bison Calves of Banff” would be a great name for a band!

More Optogenetics

I had never really heard of optogenetics until this summer, but it seems to be a flavor of the month—for good reason.   As Emily Waltz points out in IEEE Spectrum, it is being demonstrated for pain relief, as well as massively spooky manipulation of memory and behavior [1].

This super neat technology involves genetically modifying neurons so that they respond to visible light.  Then they are selectively stimulated by programmed flashes of light. Depending on the situation, the light might be projected from outside, or delivered by implanted devices. Assuming the right neurons are sensitized, and the light can be delivered, the rest is just programming, so to speak.  Digital processing can generate any neural response desired.

So far, this is being demonstrated in animals. It has been reported to control pain, to stimulate behaviors, and implant memories.  (There is no human data reported yet, so no one really knows the subjective experience of this technique.  It could well be quite strange.)

This summer, researchers report on yet another application, restoring hearing though neural stimulation [3]. The basic goal is to create very precise neural stimulation to overcome damage to the cochlea.  To date, this condition has been treated with electrodes programmed to selectively stimulate the nerves, but the electrical stimuli are imprecise, so the person receives garbled information.  The optical stimulation has the potential to be much more precise, “spatially restricted and cell-specific excitation”. ([3], p. 1)

The idea would be to implant light generator (e.g., a optic fiber), to generate very precise flashes to represent the incoming sounds.


Now, there are many challenges to work through with this technology.

For starters, genetically modifying selected neurons is, well, not a trivial step. This is generally done with a virus to ‘infect’ the targeted cells, which sounds scary but probably safe.  But there is little known about the long term effects of such treatment. Does the immune system react? How long does the mutation last (the cells might repaired or regenerated)? Are there side effects, unrelated to the intended changes?  Can the virus or the modified cells mutate or migrate to unrelated contexts?  How does it interact with other drugs?   For goodness sake, what does it feel like?

This technology in general has significant questions.  The light sensitive cells are vulnerable to unwanted signals from environmental noise or even hackers.  What happens if the person is accidentally exposed to bright flashing lights?  And deliberate attackers don’t even need to reprogram the controller, they can just flash light at the victim. I’m not eager to read about somebody’s brain being hacked by flashing lasers at their head.   How can the receiver be shielded so that only desired signals are received?

Equally worrying is the fact that this technique allows any neural patterns to be programmed, not just benign and beneficial ones.  This technique can help suppress pain, but it can also induce pain.  For that matter, it may be able to “implant” feelings of fear, false visions, memories, and thoughts.  This is an incredibly sophisticated tool for torture and maybe brain washing.  One wonders what is being done with it in black labs around the world.

In passing, I’ll also note that this might be yet another new medium for delivering porn entertainment. Forget virtual reality, forget haptic interfaces, this technology might deliver experiences directly to the brain.   And I’ll go on the record to predict that this will be extremely addictive.  Sigh.

This is clearly a big deal.

  1. Emily Waltz, Device Uses Flashes of Light to Restore Hearing, in IEEE Spectrum -The Human OS. 2018.
  2. Emily Waltz, Nanoparticles in Mice Brains Light Up, Trigger Memories, in IEEE Spectrum – The Human OS. 2018.
  3. Christian Wrobel, Alexander Dieter, Antoine Huet, Daniel Keppeler, Carlos J. Duque-Afonso, Christian Vogl, Gerhard Hoch, Marcus Jeschke, and Tobias Moser, Optogenetic stimulation of cochlear neurons activates the auditory pathway and restores auditory-driven behavior in deaf adult gerbils. Science Translational Medicine, 10 (449) 2018.

Ocean Currents Slowing, But No Ice Age Coming?

One of the big questions in Earth science is what is happening with the Ocean circulation systems, and what they are linked to.  These currents circulate around the oceans at the surface and deep below, moving vast amounts of water, nutrients, and, above all, energy around the world.  The appear to be linked to atmospheric conditions, and influence the climate on land directly and indirectly.

The Atlantic Meridional Overturning Circulation (AMOC) is a large current that flows North from the equator on the surface, cools and sinks, and then flows South deep in the ocean, where it eventually comes back up to complete a circuit.  This flow is driven by the differences in the density of warm, fresh water, and cool, salty water.  Heating the water absorbs a huge amount of the solar energy reaching Earth, energy that does not heat the atmosphere and land.  Changes to the current can potentially have widespread effects on climate, and the geological record appears to show cases when sudden slowing of the current has been associated with periods cooling in the Northern Hemisphere.

Melting Arctic ice floods the ocean with fresh water, diluting the salinity and potentially decreasing the downward pull, and slowing the AMOC.  This would reduce the transport of heat from the tropics, resulting in much cooler temperatures in the North.  Human generated warming is melting the Northern ice, which could lead to a sudden shutdown of the AMOC, triggering a new ice age.

This summer a new study based in part on new data from buoy arrays finds a more complex relationship between global temperatures and the AMOC [1].   The AMOC was at a minimum from 1975 to 1998, during which time the surface warmed.  From 1999 to 2004, the AMOC accelerated, and globally temperatures increased more slowly. The AMOC has now slowed again and is probably will remain at a minimum for a decade or more. This will almost certainly mean global temperatures will increase.

Basically, the AMOC (and probably other currents) appears to be absorbing the increased heat from the atmosphere, without triggering a sudden cooling during recent periods, and without sudden changes in the currents observed at some points in the past.  Probably no ice age in the near future.

In general, it seems that even if the current is transporting less heat to the North—which could generate a mini ice age there, the heat has to go somewhere.  If the ocean absorbs less, then the atmosphere will heat more.  The warmer air not only heats the middle latitudes, but also warms the North, too, which probably makes up for the cooler seas.

One interpretation of these hypotheses is that when the Earth is heating rapidly due to greenhouse gasses, the ocean current keep running, even as the ice melts.  Models of earlier eras may not reflect current conditions (no pun intended).

“Evidence from palaeoclimatology suggests that abrupt Northern Hemisphere cold events are linked to weakening of the Atlantic Meridional Overturning Circulation (AMOC)1, potentially by excess inputs of fresh water. But these insights—often derived from model runs under preindustrial conditions—may not apply to the modern era with our rapid emissions of greenhouse gases.” ([1], p.387)

It’s all pretty complicated, and we’ll have to see how these theories play out.

But I’d bet that things are just going to get hotter, the ice is going to melt, and the oceans are going to rise.

  1. Xianyao Chen and Ka-Kit Tung, Global surface warming enhanced by weak Atlantic overturning circulation. Nature, 559 (7714):387-391, 2018/07/01 2018.
  2. Matt McGrath, Slowing Gulf Stream current to boost warming for 20 years, in BBC News – Science & Environment. 2018.