Science – Page 2 – Journeys of Heart and Mind

Living fossils

Living fossils can be found and recognised over long periods of geological time, and appear very similar throughout. And they may have little diversity, in other words the species in the group all tend to be similar to one another.

Leaves of Ginkgo biloba, the Maidenhair tree

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Image of the day – 172

Every now and again biologists discover a plant or animal that looks uncannily like a known fossil. It’s happened a number of times.

Living fossils have two main characteristics, although some have a third:

Living organisms that are members of a taxon that has remained recognizable in the fossil record over an unusually long time span.

They show little morphological divergence, whether from early members of the lineage, or among extant species.

They tend to have little taxonomic diversity.^[5]

The first two are required for recognition as a living fossil; some authors also require the third, others merely note it as a frequent trait.

To put this more simply, Living fossils can be found and recognised over long periods of geological time, and appear very similar throughout. And they may have little diversity, in other words the species in the group all tend to be similar to one another.

Here are some examples, listed in order of their discovery. In some cases the fossil organism was already known before a living form was discovered, in other cases the living form was known first:

Dinoflagellates (1753, worldwide in salt and fresh water)
Ginkgo or ‘Maidenhair tree’ (1800s or before, southwestern China)
Echinothurioida or ‘Soft sea urchins’ (1870s, southern England)
Eomeropidae or ‘Scorpion flies’ (1909, southern Chile)
Coelacanth there are two living species (discovered in 1938 in the Indian Ocean) and (late 1990s off Indonesia).
Metasequioa ( discovered in 1941 in Hunan, China)
Glypheoid lobsters (1970s, Philippines)
Jurodidae or ‘Jurodid beetles’ (1996, Siberia)
Mymarommatidae or ‘false fairy wasps’ (2007ish, North America)
Syntexis libocedrii or ‘cedar wood wasp’ (2011, California to British Columbia)

What else can we learn from this

Two things really. The first thing is that species can sometimes exist for very much longer than normal. And the second thing we learn is that species with astonishingly similar appearance may rise independently more than once. So-called fossil species may be no more than independently arising lines that happen to look very similar.We see the same thing between different living groups, so there’s a marsupial mouse that looks quite like its European namesake. This is known as parallel or convergent evolution.

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Another umbellifer

Truth still matters

Evolution and behaviour

Pasqueflower

Plants are available from garden centres and will grow happily in your garden given the right conditions. These plants belong to the buttercup family and are near relatives of the anemones.

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Image of the day – 150

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every few days.

This makes it three in a row for flower images. The pasqueflower (Pulsatilla vulgaris) grows wild in the Cotswolds on dry grassland areas open to full sunshine. It was once quite common, and although not actually threatened, is something of a rarity these days. There’s a Cotwold dry valley site near Cirencester where there’s a reasonably large colony, but to keep the plants safe, the location is not advertised. However, plants are available from garden centres and will grow happily in your garden given the right conditions. These plants belong to the buttercup family and are near relatives of the anemones.

Protecting endangered or rare species (both plants and animals) is of ever growing importance. There are several ways species come under pressure and we’ll look at those first.

Challenges to survival

Habitat loss is the primary cause of decline for many plants, including the pasqueflower. Land improvement, especially the use of fertilisers to increase crop yields, is an issue for plants adapted to poorer soils.

Physical removal of plants or hunting of animals is an issue too. Most species can cope with limited amounts of removal, but if population levels fall drastically, there are real dangers. The dodo died out on the island of Mauritius following hunting by European sailors. The flightless birds were unafraid as they had no natural predators, so they didn’t run away from their hunters. They were welcome fresh meat after weeks at sea on salt beef.

Ecological damage also causes harm, sometimes unexpectedly. After the dodo became extinct, a tree species mysteriously stopped reproducing. Gradually the population was reduced to only older trees. It turned out that the fruit contained toughly seeds with tough shells that would only germinate after passing through the gut of a dodo. Links like this between organisms can be critical.

Climate change is another danger, especially for plants. If climate change is slow organisms can change the range of places where they grow; if it’s fast, animals might adapt, but some plants may need an entire year to move a few metres.

Pollution is a further serious issue and can exacerbate the other problems already mentioned above.

Diseases of both plants and animals can become pandemic and risk extinction, especially when populations are already stressed by droughts, loss of habitat, or pollution.

Attitudes

Given all of the above, what should our attitude be to the current situation?

Some people will shrug their shoulders. – Perhaps they don’t understand the peril the world faces, or they don’t understand the need to help the natural world recover. Or maybe they just feel there is nothing they can do about it.

Others may understand enough of the science to realise there is a danger, to see that it can be reduced (if not entirely averted), and to take some personal actions to help.

Biologists, ecologists, nature enthusiasts, and climate scientists understand only too well what is happening. Usually, they will be trying to communicate the issues whenever and wherever they can.

Followers of Jesus, and people of other faiths will often understand that we should do all we can to protect this world we live in, and live in ways that will reduce the damage.

All of the groups mentioned here are either responding already, or need help to see and understand that the natural world needs our help and that every single one of us can make a difference. Education and commitment are the way forward, so please share this post with anyone you know who might be influenced by it.

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Image of the day – 60

My Father is a farmer

The heart of a tulip

I worked as a professional botanist when I was in my twenties and thirties, studying and publishing scientific papers on pollen and pollination.

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Image of the day – 149

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every few days.

I have another flower image for you today. This one shows the centre of a tulip flower in more detail than you might normally see. I’ve placed the centre of the flower towards the lower right of the frame so you can see more of the petals towards the upper left. You’ll notice that the petals are yellow near the centre, orange a bit further out, and pink further out again. What a beautiful combination!

The reproductive parts

Tulips are monoecious, a botanical term that means each plant produces both male and female reproductive tissues. The female part of a tulip flower has three stigmas in the centre. Unlike animals and some more primitive plants, the male reproduction process doesn’t involve motile sperm. Instead, pollen is released as a yellow dust, sometimes dry and carried by the wind but in the case of tulips and many other plants, sticky and carried by flying insects.

Flowers work as attractive beacons for pollinating insects, they’re usually brightly coloured, are often fragrant which helps insects detect them from a distance, and provide food – sugary nectar at the base of the petals, and pollen. Bees collect the pollen and carry it back to the hive as a protein rich food for their larvae. Plants produce more pollen than necessary and can spare some in return for the pollen transport provided by the bees. The pollen grains stick to the pollinating insects and as they visit flower after flower, some of the pollen is transferred from the anthers of one plant to the stigmas of another. This cross-pollination is exactly what the plant needs for the female tissues to develop further and produce viable seeds.

Tulips have five of these anthers, and if you enlarge the image and peer closely you can see yellow dust clinging to them. That dust is the pollen.

Intricate

It’s an astonishingly intricate process in which the plants depend on the insects and the insects depend on the plants. I could go into much greater detail; I worked as a professional botanist when I was in my twenties and thirties, studying and publishing scientific papers on pollen and pollination. Maybe some time I’ll write a bit more about that.

Next time you see tulips in the park, at a florist or supermarket, or in your garden – just think about the intricate interactions going on right there!

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Image of the day – 93

Meadow cranesbill

Large White

A glorious colour contrast

The climate has changed dramatically in the past, but it has always happened slowly, usually taking tens of thousands of years.

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Image of the day – 148

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every few days.

Here are two flowering plants with colours on opposite sides of the colour wheel. They’re very distant relatives; the yellow Narcissus (daffodil) is a monocot, the purply-blue Streptocarpus is a dicot. You can’t get much further apart in the family tree of flowering plants, but they look well together.

These two plants simply could not survive in one another’s home territory. The Narcissus needs plenty of moisture, produces leaves in late winter, is not troubled by frost, and flowers in the springtime. It also appreciates some bright sunshine.. Streptocarpus cannot take any degree of frost at all, and is touchy about water. Not enough and it will wilt and die, too much and… wait for it… It will wilt and die! It likes the soil to dry out completely and then have a real drenching, but do not water it again until the soil is really dry. It likes shade or partial shade, but not full sunshine.

Adaptation

The fact that these two plants like such different conditions is nothing to do with the fact they are very distant relatives. All plants growing in the wild are well adapted to the soil type, climate, other plants and animals of the places they inhabit. Natural selection over many, many generations will ensure that this is so. It’s only the survivors that will have a chance to produce seeds. By definition, the next generation comes only from the plants that survived the current generation. Survivors thrive; the rest die out.

Climate change

And this in turn is one of the challenges life faces in the changing climate we are creating. The climate has changed dramatically in the past, but it has always happened slowly, usually taking tens of thousands of years to shift from ice age to interglacial, or from desert to semi-desert to grassland to forest. A species may seem to move north or south, east or west, remaining in the climate zone that suits it best. But what is actually happening is that as a climate zone shifts geographically, conditions become less suitable in one area and more hospitable in another. Perhaps the species manages to survive a little further north than before but struggles and dies on the southern edge of its old range.

This process takes time, but the global warming trends we see due to greenhouse gas releases are many times faster than any natural climate change. Populations cannot respond fast enough under such circumstances; they go into decline and die out – the species may then become extinct, gone forever.

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Christmas cactus

Firethorn berries

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An old survivor

Much of the old tree would have survived for while, so the new shoot was shaded and would have grown out at an angle, attracted towards the light. Since then, the new growth has itself become a mature tree.

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Image of the day – 138

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every day or so.

I spotted this old tree when we visited Blenheim Palace today. It’s probably an ancient oak though I didn’t get close enough to check with certainty.

The thickest part, the lumpy-looking base is the remaining stump, all that remains of the original tree that would have grown from an acorn many hundreds of years ago. That tree was a sapling, then a youthful, vigorously growing tree; eventually if became a mature, majestic oak. But then the rot would have set in – literally. Holes made by a woodpecker, or damage from a storm cracking off a branch, gave access to unprotected wood beneath the bark. Insects may have burrowed into the wood, and eventually fungal spores would have germinated and started the decay process in earnest.

The weakened tree would have lost its vigour and been reduced to a hollow stump and failing branches. But finally, a new shoot must have appeared near the base and formed new, young growth. Much of the old tree would have survived for while, so the new shoot was shaded and would have grown out at an angle, attracted towards the light. Since then, the new growth has itself become a mature tree.

Another possibility is that a branch of the original tree survived, and with the other branches missing, grew into the shape we now see. A careful examination of the tree might reveal the truth. But however this curious old tree survived, it certainly has an unusual story to tell!

Donna and I enjoyed our day at Blenheim and will visit again from time to time this year as the seasons roll by. I’ll probably write about the place again.

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Asteroid heading our way

There is absolutely no need to panic. If you’ve heard about this and are worried, calm down and read on for the simple facts and where to go for more detail.

Image: Wikimedia

Science and technology – 4

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There is absolutely no need to panic. If you’ve heard about this and are worried, calm down and read on for the simple facts and where to go for more detail.

I imagine almost everyone will have heard about this asteroid by now. News stories have varied from rather scary to suggesting the risk is extremely tiny, so letߴs begin by setting out the most important things to know:

The full name of the asteroid is 2024 YR4
It will pass Earth in 2028, but will definitely miss
It has about a 2% chance of hitting Earth in 2032
It therefore has a 98% chance of missing entirely in 2032
As we define its orbit better, the chance of a hit is likely to drop to zero
If the chance of a hit becomes large, we can probably nudge it to miss

If it does become clear that the asteroid will hit Earth, here are some further important things to know:

We already know the ground track along which it would hit
It would most likely fall in the Atlantic Ocean
If so, it would cause a very large tsunami
It might fall in South America or Africa and make a crater 1.5 km wide
It would destroy everything over a much larger area outside the crater
We would have plenty of time to move people out of the way, either from coastal areas in the event of an ocean hit, or from the impact zone if the asteroid hit land. Clearly, many lives could be saved but it would be very costly.

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Greenshifting

Plants (secondary) trap some of the energy in sunlight and use it to grow and to store in chemical form. And animals (tertiary) obtain energy by eating plants or other animals.

Image: Wikimedia

Science and technology – 3

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We’ve just had a heat pump system installed in our home and it is so, so different from the old, gas-fired boiler that used to keep us warm in winter. I’ll give you some details about it in another article. But the main reason I’m writing is to explore what it means to be migrating towards clean, green energy; and what it means if we fail. But before we can focus on any of that, we need to understand where our energy comes from and where it goes.

Primary energy sources

We all use energy every day, as a species. And just like all other forms of life, that energy comes almost entirely from rearrangements within atomic nuclei. There are two ways this can happen – nuclear fusion and nuclear fission. Fusion is what happens in the centre of the sun where hydrogen atoms are combining to form helium, releasing a lot of heat in the process. Fission is what happens suddenly in a nuclear bomb or slowly in a nuclear reactor. Heavy atoms fall apart and release energy as they do so. The rule is that heavy elements release energy if they break apart (fission), while light elements release energy if they join together (fusion). Elements in the middle mass range around iron don’t break apart or join together easily and produce little or no energy if forced to do so. Indeed, sometimes these elements might require energy.

The sun’s energy comes from fusion in the core and is eventually released as sunshine. Sunshine heats the Earth’s surface and winds are caused as air masses expand or contract due to temperature changes. Waves, in turn, are caused by wind crossing water surfaces.

Some of the Earth’s inner energy comes from the spontaneous fission of heavy elements in the core and mantle, and some is remnant heat from Earth’s formation 4.5 billion years ago; that core energy is released in the form of volcanoes, earthquakes, and hot springs.

Tidal energy is the final source we need to consider. This is the result of gravitational forces from the Sun and Moon causing bulges in the oceans, the Earth revolves daily beneath these ocean bulges and the water depth varies as the state of the tide changes throughout the day.

It’s also gravitational contraction that gets the centre of a star dense enough and hot enough for fusion to begin in the first place. That’s it for primary energy sources. All of these count as green energy as none of them release carbon dioxide.

We can collect solar or wind energy, for example, with a clear conscience, also geothermal energy, hydroelectric power, hot springs, tidal power, or nuclear. There may be issues with all of these, but none of those issues have anything to do with releasing greenhouse gases.

Plants and animals

Everything else is what I call secondary or tertiary energy. Plants (secondary) trap some of the energy in sunlight and use it to grow and to store in chemical form. And animals (tertiary) obtain energy by eating plants or other animals. These too can be counted as green. The natural world runs on light from the sun, and all the carbon dioxide released is balanced by the light trapping mechanism of plants that uses carbon dioxide from the air and water from the ground and releases oxygen. The carbon is used to create the structural elements of wood and all the living tissues of plants and animals. Most of this is recycled naturally by decay within a few years or decades, and the carbon balance of the Earth doesn’t change. Except sometimes carbon containing materials were trapped long term in geological deposits of coal, oil and natural gas. This sequestration of carbon compensated for the continual, slow warming faced by the planet as the sun increased its output of light and heat over geological time.

Deep time

All stars grow brighter and hotter as they age, a perfectly natural and well understood process that we don’t need to consider here – except to mention that it happens. Rising temperatures cause shifts in a planet’s climate, and if it goes far enough a planet can become very hot, lose its water to space, and become a roasting desert like Venus.

This did not happen to the Earth because the continual, slow removal of carbon from the surface kept carbon dioxide levels low and significantly reduced the greenhouse effect.

Early human technology

Early human technologies did not involve the use of coal, oil or gas. When fire was first discovered and tamed for human use, the only fuels were wood and various kinds of plant and animal oils and fats. Our technology remained green, using only recently captured energy.

But around 4000 years ago, people began to discover surface deposits of coal and oil. The Romans and the Chinese knew of coal and used it on a small scale as a fuel.

We were still remaining green on the whole. The industrial revolution began with water power to mill grains, process wool into cloth, and so on. The first industrial towns were always built in valleys where there were rivers of sufficient size to power the machinery. Up to this time it’s difficult to find much change in atmospheric carbon dioxide levels in, for example, ice cores or ancient timber. When carbon fuel was needed for processes needing extreme heat (eg iron smelting, pottery firing), charcoal was used; this was made by incomplete burning of wood in an oxygen poor environment.

But then came steam power!

Advancing industrial growth

It soon became clear that charcoal was not available in sufficient amounts to be a suitable fuel for burgeoning industry. Instead, coal began to be mined in ever-increasing quantites to feed iron and steel works, power pumps to move water from mines, and more and more to power transport. Railways and shipping consumed ever larger amounts of carbon in the form of coal. Oxygen was consumed and carbon dioxide released – and at that point the human race started on a dangerous path towards climate change. At first the increase in carbon dioxide levels was imperceptible and so was the increase in average temperatures.

And that is where we were 100 years ago.

Oil is not mainly carbon, like coal. It has almost two hydrogen atoms to every carbon in its structure so it’s slightly more green than coal. Hydrogen oxide (aka water) is a less powerful greenhouse gas than carbon dioxide. Gases are even better than oil, methane is best of all as it contains four hydrogens to every carbon.

But to be fully green we must move all our energy production to solar, wind, nuclear, and tidal energy supplies. There are financial incentives to make the move too. To burn coal, oil or gas at a power station you must construct the power plant and transmission lines and then continually buy the raw materials to burn to generate power.

Wind turbines, solar panels and hydro also involve building infrastructure, but the fuels to run them – sunshine and wind – are free. This makes the energy they supply to the power grid much cheaper than energy from non-green technologies.

The economical costs of mining or drilling, as well as the health and environmental costs of emissions from non-green energy sources renders the move to greener energy an absolute no-brainer. And that’s before we start to take into account the serious risks of a warmer climate. These include rising sea-levels; unlivably high temperatures; heavier and unpredictable rain; forest fires; spreading of deserts; and harsher and more frequent cyclones and hurricanes. All of these horrors are already with us and are worsening year on year by larger and larger amounts.

Back-pedalling furiously cannot save us now. But it’s not too late to moderate the damage, eventually stabilise the problems we face, and see a gradual return to what was once normal. But we absolutely must act now, the longer we leave it, the worse it will get.

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Science and technology – 1

Getting enough sleep is important of course, but the quality of our sleeping matters too. Good exercise, diet and quiet, undisturbed surroundings are helpful factors.

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Welcome to a new feature on JHM, a series of articles on science and technology. I’ve posted articles like this before, but not as a regular series. From now on science and technology articles will be easier to find and browse with their own index.

This time, we look at the topic of sleep.

Sleeping well

Why sleep matters

Sleeping well is clearly important. We all know that lack of sleep makes us tired, perhaps a bit grumpy, and affects our ability to focus. We’re more inclined to doze off, and microsleeps lasting a second or so can be absolutely deadly (quite literally) for someone trying to drive or use heavy machinery.

But there are longer term health effects too (see the Nature article listed below).

Improving your sleep

The New Scientist articles cover many aspects of sleep. Getting enough sleep is important of course, but the quality of our sleeping matters too. Good exercise, diet and quiet, undisturbed surroundings are helpful factors. It’s useful to consider how our time awake will affect our sleep. There are hormonal effects affecting both falling asleep and waking up – melatonin and cortisol – so we need to consider those as well.

In terms of practical advice, useful tips include – using bright lighting in the morning (especially in wintertime), and dim lighting in the evenings – keeping the bedroom cool and dark – avoid eating and drinking late in the evening and be wary of late caffeine intake – avoid stress near bedtime if possible.

Surprisingly, perhaps, your gut microbiome is another factor, and it works both ways. Sleep patterns can affect the microbiome, but a healthy microbiome helps provide better sleep.

Going deeper

The links below provide further reading. The New Scientist link will give you an overview with introductions to all the articles, though if you want the full text you’ll need a subscription or access to the printed version Many libraries will have a copy.

The other two links are free for the full text.

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Light from street, Moon and planet

The Moon hangs in the sky to the right of the house, and it’s 390 million km away, so light takes 1.3 seconds or so to make that trip.

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Image 118 – What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every day or so.

This photo is of the northern end of Gloucester Street, seen from the eastern side of the River Churn, close to Abbey Way Services.

You’ll notice several sources of light. Light travels at a little over 1 billion km/h, 1.079 billion if you want to be a little more precise. Like anything in motion at a steady speed, you can express distances in terms of travel time. If I fly a helicopter in a straight line to London at 100 km/h and it takes me an hour, then the distance to London must have been 100 km. If it takes only 30 minutes, then the distance was 50 km. You get the idea.

The streetlight, the house and the car are all around 20 m away (or 0.020 km), and doing the arithmetic shows that light would take around 80 billionths of a sec to make that trip.

The Moon hangs in the sky to the right of the house, and it’s 390 million km away, so light takes 1.3 seconds or so to arrive from the Moon.

The planet Venus is visible near the top of the photo, and as I write Venus is about 111 million km away, a distance that light covers in just over 6 minutes.

For comparison, our nearest neighbouring star, Proxima Centauri, is so far away, that its light takes 4¼ years to reach us. Space is BIG!

When: 2nd January 2025
Where: Gloucester Street, Cirencester

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Cirencester

For convenience, here’s a list of all the Cirencester area images:

A417 roadworks, Advent Market, Bishops Walk, Baunton, Canal 1, 2, Castle Street, Christmas lights 1, 2, Church 1, 2, 3, 4, 5, 6, Churn flood, Countryside, Fallen tree, Fleece, Gasworks, Gloucester Street, Hare 1, 2, Hospital, Market Place 1, Phoenix Fest, Riverside Walk, Stone plaque, Stratton Meadow, Tank traps, View, Wonky 1, 2, Yellow Iris

Themed image collections

The links below will take you to the first post in each collection

Cirencester, Favourites, Irish holiday 2024, Roman villa

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Where is the sea-ice going?

The time to begin thinking about consequences and mitigation is now, not in ten or twenty years time.

Antarctic sea-ice

The news headlines are covering all kinds of world issues – the Russo-Ukrainian war, the revolution in Syria, Donald Trump’s coming second term in the White House, world economics, and more.

But there’s an event going on of far greater importance than any of those other issues, and that concerns the latest results of research into Antarctic sea-ice.

The problem? It’s melting much faster than we thought.

And why is that such a big deal? Because of the implications that global warming is progressing so much faster than we realised, combined with the potential loss of ice shelves, one and a half metres of sea-level rise far sooner than we expected, and the further potential for catastrophic sea level rises much, much greater than that.

That’s alarming in anyone’s book. But it’s not alarmist, it’s just stating an unpalatable truth. The time to begin thinking about consequences and mitigation is now, not in ten or twenty years time. And it’s most certainly way past time to deny that climate change is a thing at all.

I urge you to listen to the New Scientist podcast on this, episode 279 released on 6th December 2024. It has all the details.

Image of the day – 172

What else can we learn from this

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Image of the day – 150

Challenges to survival

Attitudes

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Image of the day – 149

The reproductive parts

Intricate

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Image of the day – 148

Adaptation

Climate change

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Image of the day – 138

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Science and technology – 4

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Science and technology – 3

Primary energy sources

Plants and animals

Deep time

Early human technology

Advancing industrial growth

See also:

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Sleeping well

Why sleep matters

Improving your sleep

Going deeper

See also:

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Cirencester

Themed image collections

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