Deep Sea Mining, Indian Ocean, Infectious Diseases

Some readings for you:

1) Mining the bottom of the sea: The deep sea bed is considered the last frontier on earth for mining. Large patches of the sea bed are littered with metallic lumps or nodules rich in manganese, cobalt, zinc, and nickel. These elements are considered vital for powering the world's green economy. Nauru, a tiny Pacific Ocean island nation situated northeast of Papau New Guinea, along with a Canadian mining company, wants to start mining a region of the Pacific between Hawaii and Mexico known as the Clarion-Clipperton Zone. Scientists warn that a hurried push to mine the deep ocean bed will result in an irreversible loss to biodiversity, ecologic functioning, and ocean health. Elizabeth Kolbert writes about the complex legal and regulatory issues and conflicts of interest related to international deep sea mining.

As things stand in June 2024, a deep sea mining code is still being decided by the International Sea Bed Authority. Rohini Krishnamurthy of Down to Earth has the latest news on the progress made on this issue. Negotiations are hampered by a lack of basic science and divergence of views between member states.

2) Indian Ocean headed for a near-permanent state of marine heat wave:  Rapid fossil fuel emissions over the past century or so has changed the earth's energy balance. More energy is now coming in than is being radiated out to space. More than 90% of this excess energy is ending up in the ocean as heat. As a result, the world's oceans are warming up. The Indian Ocean is warming rapidly too. Recent studies have found that it may be heading towards a scary sounding situation known as 'permanent heatwave state' where the sea surface temperatures exceed a threshold value for 220-250 days a year.

Environment and climate journalist Nidhi Jamwal summarizes the findings of this research and a new book titled The Indian Ocean and its Role in the Global Climate System. The consequences are far reaching, impacting tropical cyclones, biodiversity, and fisher folk livelihood.

3) Probing the pathogens that afflicted ancient humanity: Pathogens and humans have been co-evolving for millennia. Paleoanthropologist John Hawks charts out the history of some of the common infectious diseases afflicting humanity. Infection patterns are not random. Rather, they follow networks of transmission shaped by ecology and culture. Very illuminating essay!

Links: Long Covid, Galapagos Islands, Origin Of Life

 I enjoyed reading these over the past few days.

1) Clues to Long Covid:  The disease that has affected us over two long years is still quite a mystery. Jennifer Couzin-Frankel has written a very informative article on the quest to understand Long Covid and how to treat it. 

2) The Galapagos Is a Glimpse of Eternity.  Geology influence organismal habitat and life habits. Penguins nesting in lava tubes. Tortoises finding warm volcanic vents to raise their body temperatures. Paul Stewart describes the landscapes of the Galapagos Islands with its amazing biodiversity, now threatened by climate change. 

3) From Pre Biotic Soup To Fine Grained RNA World. I often come across new articles breathlessly announcing that organic molecules of various types have been found on asteroids. But whatever the source of different molecules, it is specific conditions on early earth that we need to understand to arrive at a sensible theory of the origin of life. Fine article by Philip Ball.

Peopling Of The Americas- Rapid Settlement And Substantial Lineage Extinction Upon European Contact

Here is the full paper : Ancient mitochondrial DNA provides high-resolution time scale of the peopling of the Americas

The exact timing, route, and process of the initial peopling of the Americas remains uncertain despite much research. Archaeological evidence indicates the presence of humans as far as southern Chile by 14.6 thousand years ago (ka), shortly after the Pleistocene ice sheets blocking access from eastern Beringia began to retreat. Genetic estimates of the timing and route of entry have been constrained by the lack of suitable calibration points and low genetic diversity of Native Americans. We sequenced 92 whole mitochondrial genomes from pre-Columbian South American skeletons dating from 8.6 to 0.5 ka, allowing a detailed, temporally calibrated reconstruction of the peopling of the Americas in a Bayesian coalescent analysis. The data suggest that a small population entered the Americas via a coastal route around 16.0 ka, following previous isolation in eastern Beringia for ~2.4 to 9 thousand years after separation from eastern Siberian populations. Following a rapid movement throughout the Americas, limited gene flow in South America resulted in a marked phylogeographic structure of populations, which persisted through time. All of the ancient mitochondrial lineages detected in this study were absent from modern data sets, suggesting a high extinction rate. To investigate this further, we applied a novel principal components multiple logistic regression test to Bayesian serial coalescent simulations. The analysis supported a scenario in which European colonization caused a substantial loss of pre-Columbian lineages.

Several points of interest come to mind.

a) Separation with Siberian common ancestors took place about 24 thousand years ago, followed by a long period of isolation in Beringia (see Fig.).

The founder lineages then settled the America's quite rapidly beginning around 16 thousand years. Sites in Chile show human habitation by 14 thousand years.

b) The much talked about Clovis culture were not the first Americans.

c) There was a demographic collapse among the Native American populations. Charles Mann's 1491 gives quite a sweeping account of both native and Spanish eye witness accounts of the wiping out of entire tribes and communities due to Old World diseases. This paper backs that up using genetics. A comparison of ancient DNA with present day Native American DNA shows that extensive extinction of mitochondrial lineages took place.  In plain language, entire tribes were wiped out to be replaced  much later by natives migrating from some other place, although the authors caution some of the discontinuity of lineages could be because  modern diversity may have been undersampled.  The data for ancient DNA comes principally from the western coast of South America which had large Native American population centers.   Lowland populations went extinct more. Highland populations were less affected. Perhaps population contact was more in the lowlands and diseases like malaria more prevalent in the warmer climes?

Confused Article In The Hindu On Evolution, Disease And Paleolithic Lifestyles

What's up with The Hindu?.. another terrible article on science and evolution and biology by a medical professional soon after the recent ignorant hateful essay on homosexuality. Following reader outrage and detailed corrections that article on homosexuality has been retracted by The Hindu.

This one is by a cardiologist Dr Hegde. He begins thus:

Darwinian evolution has become outdated and its place is taken by the Lamarckian hypothesis of evolution by environmental compulsions. Darwin himself agreed with Lamarck but the neo-Darwinians, who have a big business interest in keeping the status quo, are at it even now. Even Erasmus was for environmental evolution long before Darwin came into the picture. Most of our pathophysiology of diseases is based on the Darwinian model unfortunately and it has to change for good. Earlier the better.

Darwinian evolution dead but kept alive by a conspiracy of big business... What utter rubbish! Later Dr. Hegde complains that "medical doctors do not go into evolutionary biology, even if a few of them go into biology". I hope he has counted himself in that list of medical doctors not getting into evolutionary biology for the above para is as uninformed as it gets.

Lets gets some terminology out of the way.

What Disease Did To Europe

From The Economist : Plagued by dear labour

Most of the article is about a debate on whether the population crash due to the plague outbreaks in the mid 1300s Europe brought about real improvements in wages and labor rights.

and then this speculation:

A more speculative theory suggests that the Black Death encouraged Europeans to become more imperialistic. Prior to the Black Death, Europeans were rather averse to long sea voyages, given the extremely high death rates on boats. But as death rates on land soared, people became less afraid of sea travel; it was not much riskier than staying at home. As a result, colonialism was kick-started. Mr Belich links the plague to the “spread of Europe”.

Interesting-- i would think the more immediate reason that triggered widespread European exploration and imperialism was a desire in Christian Europe to break the Muslim domination of Indian Ocean and Arabian Sea merchant routes. With this disease theory one can argue that it was high death rates on land that made Europeans get over their timidity of sea voyages.  Another factor is that advances in ship building made long voyages less risky and produced ships big enough to make voyages profitable. Dom Henrique (better known as Henry the Navigator) the younger son of the King of Portugal in the early fourteen hundred's was asked to find a land route across the Sahara to break the Muslim bottleneck on the Red Sea and Persian Sea routes. He realized the foolishness of this venture and began collecting navigation charts of the African coasts and became a patron of ship builders. That subsequently led to explorers like Batholomew Diaz and Vasco De Gama to finally round the Cape of Good Hope and find a passage to India and the East Indies spice riches.  Again with this disease theory one can argue that disease and the population crash triggered innovation in general and one result was advances in ship building!.. so you can end up putting the disease theory at the root of any complex causal chain and explain all sorts of intangibles with it.. that makes me wary..

Reassembling Pangaea In The Year 1493

This is the second great talk I have heard on Fresh Air in the past few days. Author of the book 1493: Uncovering the World Columbus Created Charles Mann talks about the impact on the Americas and Europe due to the sudden exchange of humans, animals, plants, parasites between the continents following Christopher Columbus's voyage to the America's in 1492.

He frames this exchange within a larger geological context -

Mr. CHARLES MANN (Author, "1493: Uncovering the New World Columbus Created"): Well, if you think about it, you know, there's been a tendency in textbooks now to kind of downplay Columbus because they say he was a bad guy, and he mistreated Indians, and he discovered the Americas by accident and so forth.

But to ecologists, he was this super-important figure, and the reason is that 200 million years ago, as you remember learning in school, the world was a single, giant land mass they call Pangaea, and geological forces broke it up, creating the continents we know today. And over time, they developed completely different suites of plants and animals.

And what Columbus did was bring the continents back together. He recreated Pangaea, in effect, and as a result, huge numbers and plants and animals from over there came over here, and huge numbers of plants and animals from over here came over there, and there was a tremendous ecological convulsion, the greatest event in the history of life since the death of the dinosaurs.

As an aside.. he is right off course that after the supercontinent Pangaea broke up more than 200 million years ago, different continents had evolved different suites of plants and animals. But Europe, Asia and the America's were not completely isolated from each other from the breakup of Pangaea until the Columbian exchange. From time to time during the early Cenozoic there were faunal exchanges ..mammals especially migrating via the Beringia land bridge (Siberia -Alsaka) to and from between Asia and America and via the Greenland land bridge in the early Cenozoic between Europe and America. These immigrants also must have caused ecological upheavals of their own. They would have been competition for resources and they must have brought over parasites and caused much death and destruction. We have a more guilt free dispassionate view of these faunal turnovers and extinctions. Tim Flannery has the details of these ancient exchanges that took place tens of millions of years ago and the ecological history of the America's in his excellent book The Eternal Frontier.

Charles Mann though weaves many fascinating stories of the Columbian exchange. One that caught my eye was on the impact of malaria on the institution of slavery. The climate which made the southern parts of the America's friendlier to intense plantation agriculture were also environs in which malaria thrived. Africans were more resistant to this newly introduced disease while indentured servants from Britain and Europe who were more commonly hired to work the fields in the earliest days of colonial settlement were dying off in great numbers. It made economic sense to start bringing over more Africans to work on the plantations.

The word exchange means that the movement of people, animals, plants and diseases went both ways. The damage in terms of human deaths, deprivation and societal disruption though was overwhelmingly more in the America's. I have often come across a common impression that it was technology, firepower and political and financial institutions that gave Europeans the decisive advantage over Native Americans. Those did play a role, but the factor that titled events in favor of Europeans was the evolutionary history of peoples, rather resistance or lack thereof to disease. In a strange twist of fate, Europeans benefited from both a lack of resistance to certain diseases as well as from resistance to others. A lack of resistance to malaria stopped newly arriving European poorer classes from being tied to harsh servitude in plantations in the south where malaria was prevalent. Instead resistance to malaria lead Africans into bondage. On the other hand Europeans had evolved immunity against small pox and many infectious diseases contracted from domesticated animals from time to time. Native Americans had not encountered small pox before and not having a history of animal domestication lacked immunity against animal diseases that occasional jumped hosts. They died in their millions leaving vast swathes of countryside unattended and empty for European settlers.

America though had its grotesque revenge via the potato and guano which was used as a fertilizer. Originating in Peru, the two teamed up and initiated intense potato cultivation all across Europe. Ireland especially became addicted to the potato. But the spud carried with it a fungal parasite. In the mid 1800's the potato crop all over Europe failed. More that a million Irish died of starvation partly due to the blight and partly due to Britain's refusal to divert grain to Ireland.

One last fascinating demographic titbit about the role of Africans in building North America:

..And the second thing is that what happened after the Europeans came was not so much that Europeans came, but the Africans came. The number of Africans who came to the Americas up till about 1840, 1850 far outweighed the number of Europeans. There were three Africans for every European who came to the Americas in those first couple hundred years.

GROSS: And this is because of slavery.

Mr. MANN: Because of slavery. And so the Europeans who came, like, you know, many of my ancestors in the later part of the 19th century came to landscapes that had been radically changed, but they had - and to new cities. But those cities had been built (by) African hands, the landscapes had been reworked by African hands, the boats that were going up and down the rivers were piloted by African crews. And so that - there was a tremendous change in the very distribution of the human race on the planet as a result of Columbus.

Globalization has done great things to us as a people, but it has been served up with more than its fair share of pain.

Listen / Transcript

India Hotspot for Emerging Diseases

From National Public Radio another eye opener on emerging diseases. A team of researchers from the Consortium for Conservation Medicine, the Institute of Zoology (London) , Columbia University and Univ. of Georgia have shown that infectious diseases such as SARS, Ebola, AIDS are on the rise and their emergence likelihood is spatially non-random. Some places are more likely to act as sources of these diseases than others. Being something of a spatial analysis buff and a map freak I found this most revealing:

Source: Nature

a) zoonotic pathogens from wildlife
b) zoonotic pathogens from non-wildlife
c) drug-resistant pathogens
d) vector-borne pathogens

Spin the combinations any way you like and India especially north India emerges as a hotspot for emerging diseases in every which way. Not very surprising considering the very high population density and proximity with domesticated animals. The recent outbreak of Avian Bird flu in West Bengal is a reminder that such threats are real and the assessed risks are not an outcome of some computer simulation done in a far away lab. In this case Indian authorities acted promptly to control the threat and even received a commendation from the UN Food and Agriculture Organization. Yet there are still worrying trends that we have be aware off. Take case d in above figure, the one that indicates risk distribution of vector-borne pathogens. Nearly all of India is a high risk area. It's not just population density that is the problem but the abysmal state of public sanitation and cleanliness in our cities and villages. The Surat plague epidemic some years ago shows that this is a clear and present danger we face. Case a which is risk from pathogens from wildlife also takes a more urgent meaning especially in the light of recent reports of deforestation and dwindling tiger populations. I have written about these issues in earlier posts from a perspective of biodiversity and wildlife protection, but human wildlife interaction is increasing in India due to encroachment into forest by people living at the margins of these forests and by continued logging of dense forests. This is what Kate Jones one of the paper authors had to say:

“Emerging disease hotspots are more common in areas rich in wildlife, so protecting these regions from development may have added value in preventing future disease emergence”

There is a positive spin to everything. The fact that this research identified India as a hotspot for pathogens from wildlife indicates we still have some wildlife areas left intact! Protecting them will be good for both animals and people.