THE BIRDS AND THE BEES
‘We see things not as they are but as we are.’
The Talmud
Around 70 million years ago (25 million years before birds with artistic specializations emerged) plants were creating a very refined form of sexual display, which would take interdependence between diverse creatures in a radically new direction.
It had started millions of years before when some low-growing plants evolved into angiosperms by producing flowers instead of cones and protecting their seeds in an ovary.
When the flowers opened, some of the sticky male cells (pollen) drifted onto a female organ nearby, and so set their reproductive process in motion. Fertilization could take place in the same flower, in another flower on the same plant, or on a flower of another plant. As usual, reproduction involving two plants increased a species’ genetic diversity, and with the wind’s help their pollen spread far and wide.
But now early water lilies and low-growing magnolias were displaying larger, coloured or fragrant flowers, and magnolias were growing taller too. They were vying for the attention of a range of insects and birds that noticed and responded to various hues and scents.
From an evolutionary point of view, it seems clear that the sensitivity of different pollinators to a different range of colours within the floral smorgasbord seems to be another example of conflict avoidance. Plants and animals both benefit from operating within a niche market.
As the insects and birds harvested sweet nectar from flowers shaped to suit them, they collected pollen on their bodies. When they visited other flowers of that species, pollen rubbed off on a female sex organ in enough cases to increase the reproduction rate above that from wind pollination.
Like other plants angiosperms still set more seeds than necessary, and some birds and animals still ate the excess.
Soon some plants were giving their seeds a protective coating so that they could lie dormant for longer, while others started growing nutrient-rich fruit around their seeds to provide ready-made fertilizer for the seed when it dropped and decayed. Some fruit became juicy and sweet when ripe, and even brightly coloured. And so its scent or hue attracted other birds and animals, which either discarded the seeds after eating the fruit or swallowed and excreted them somewhere else.
Meanwhile a few plants began to protect their seeds or leaves with toxins to discourage food-seekers, and a few animals were in turn developing a liver that filtered out the toxins. Today some fungi use not only poison to discourage potential consumers, but also bright colours like red – ignored at the forager’s peril.
All this interaction is based on protecting and passing on diverse ways of being alive, and communication within the system is an integral part of that.
(One example of Australian flower and animal coevolution is the nectar-flow of banksias and grevilleas in certain areas. It coincides with the breeding season of local honey-eating birds, with their specialised brush-tipped tongues. And it also triggers the breeding season of their predators: kookaburras, goannas and snakes.
(Honey-eating and fruit-eating mammals that feed at night, like possums and bats, are also part of these ecosystems. As today’s bush-regenerators in the Blue Mountains know only too well, in disturbed ecosystems some exotic plants also successfully co-opt native animals, particularly birds, in generating and spreading their offspring.)
The mechanism of an animal’s colour vision is an integral part of its way of living. Flower, fruit and insect harvesters need tg be able to distinguish colours, often including those in the ultra-violet part of the spectrum, while animals that feed on grass or meat have little or no such need.
The physics and chemistry involved in the actual production of colour, however, is much more complex.
As it is in Earth’s rocks and minerals, it seems to be basically a matter of a range of pigments, a process that started as we have seen with the green photosynthesizing pigment chlorophyll. But in birds like peacocks and flying insects like butterflies it is often a process of developing a series of reflective surfaces that scatter light into a range of colours.
Theories based on either random or creative evolution cannot yet explain how this emerged, or how the wonderful complexity of colour and light used by a range of animals in communication emerged. (A not-so-well-known example is seen in today’s cuttle-fish gathering to spawn off Australia’s south coast.)
Back in our story several flying insect families engaged in co-evolution with flower-bearing plants were by now undergoing a more drastic kind of metamorphosis - from a soft larval form through pupation into a very different adult form.
Their transformation within the pupa is very mysterious. The cells making up the larva break down into a genetic soup, from which adult cells gradually emerge, divide, multiply and differentiate.
A few biologists think that this is a remnant echo at the cellular level of an ancient battle, in which an early flying insect took over the body of a soft-bodied crawling insect. If this remarkable theory is true, it is yet another example of competition being transformed into joint effort.
Some of these insects were also creating distinctive social groups. Like dinosaurs and mammals they limited the number of offspring, and then spent a lot of time and energy looking after them - but they had an idiosyncratic way of doing it.
Their strategy was to clump lots of infertile females around a very fertile ‘queen-mother’, with a few males being specially produced just before her single mating-time.
The colony‘s members built a communal home around her eggs and helpless larvae and then formed separate nursery and defence cohorts, using chemical signals to communicate with each other in an instant. Most scientists describe such groups as operating like a complex organism because they work in such close co-ordination - like cells in a single being.
As anyone who has kept bee-hives knows, warrior bees in a hive that has lost its queen fight in wave after wave of suicide squads. And ant warriors are particularly aggressive in the first years of a colony, when they have many young to feed and only a few adults foraging for food.
Of course most metamorphosing insects did not develop societies. Today, like virtually all spiders, and like monotremes, they live alone but for a brief and dramatic mating. Some, like moths and butterflies, lay their eggs on a beautiful tasty leaf, from which the larvae crawl onto other leaves, eating and growing until their biological clock tells them to pupate. And some, like wasps, carefully prepare a burrow and lay their eggs inside in or on a ready-to-eat meal – either still alive or specially killed.
(Many Australian native bee species are also solitary – and stingless. We are only beginning to appreciate their uniqueness and diversity. Our iconic social insects are termites - either inspiring home-builders or devastating home-wreckers, depending on your point of view. They have also made themselves useful to people in northern Australia over thousands of years by hollowing out tree branches, which men then use to make a unique musical instrument – the didjeridoo.)
Today we see social bees, wasps and ants as the embodiment of vigorous protection of one’s territory against outsiders. Whether it emerged among them or not, territorial protection is an essential part of coevolution, limiting local population growth and thus reducing potential competition for resources, and also enabling the development of self-protection skills.
Most animal species today see protection of territory from outsiders and local competitors as a top priority whether they live in groups or have a solitary lifestyle. Plants are also territorial to different degrees. (In the Upper Blue Mountains the most notorious examples are noxious weeds like blackberries and montbretias.)
As we have seen with colour vision, the members of each species within an ecosystem perceive only a fraction of the total reality of their territory. They take in only what they need to know in order to have a chance of surviving and thriving. Since their most urgent needs relate to food and water, reproduction, and avoiding or escaping danger, they generally see the world through this frame of reference (whether instinctive or learned).
At this point in our story a flowering plant’s frame of reference for an insect was its hairy legs and wings (pollen-courier). A plant-eating dinosaur’s frame of reference for a tree was its tasty leaves (browser food). A dung beetle’s frame of reference for a dinosaur was its tasty warm dung (dung beetle food) and big feet (danger).
The point is that such frames of reference are absolutely functional - as long as there is no sudden change that threatens a whole eco-system’s survival.
But around 65 million years ago Earth’s Fifth Major Mass Extinction occurred. Tectonic movement had separated Africa and South America, pushed India north, almost split Australia and Antarctica and moved Africa’s northeastern corner closer to Eurasia. Now the Atlantic Ocean was widening, with the usual violent disturbances.
(New Zealand had also begun breaking away from Australia, warping its east coast, and pushing up the Great Dividing Range.)
Then an asteroid with a diameter of about 12 km hit Mexico on today’s Yucatan Peninsula (at the time under shallow water). It left a crater 170 km wide and ruptured into several huge segments that apparently flew into the air before returning to make further devastating impacts. Earthquakes and tsunamis occurred across the globe, along with acid rain, a global firestorm and a huge cloud of dust, which blocked out the Sun’s light and heat for many months.
In the following mass extinction ecosystems that had flourished for millions of years started to break down. Within a few thousand years 65% to 70% of species were made extinct, including many animals in the water and on land and virtually all those on land weighing more than 20 kilograms as adults. Among those that disappeared were the iconic ammonites and around 1,000 species of dinosaurs - an order of land-vertebrates that had been extremely successful for 160 million years.
Remember that this transformational change was due to a completely unexpected series of events, and thus beyond the capacity of most animal species to adapt. Earth’s environment may be largely supportive, but it can never be absolutely stable.
And yet many species of insects and also of some small birds and mammals managed to survive both the initial catastrophe and its long-term effects.
Perhaps this was the original stimulus for migration in birds. They would have had to fly long distances in search of isolated patches where the environment was not so hostile. We will come back to this in ‘Our Third Age’.
Meanwhile small mammals were no doubt helped by their ability to regulate their body temperature, together with their furry skins, burrowing skills and nocturnal lifestyle - as well as their practice of getting protein from a wide range of insects.
But from our point of view the main effect was the demise of large dinosaurs, because it cleared the way for a wider range of mammals, including us, to evolve in spectacular ways.
It had started millions of years before when some low-growing plants evolved into angiosperms by producing flowers instead of cones and protecting their seeds in an ovary.
When the flowers opened, some of the sticky male cells (pollen) drifted onto a female organ nearby, and so set their reproductive process in motion. Fertilization could take place in the same flower, in another flower on the same plant, or on a flower of another plant. As usual, reproduction involving two plants increased a species’ genetic diversity, and with the wind’s help their pollen spread far and wide.
But now early water lilies and low-growing magnolias were displaying larger, coloured or fragrant flowers, and magnolias were growing taller too. They were vying for the attention of a range of insects and birds that noticed and responded to various hues and scents.
From an evolutionary point of view, it seems clear that the sensitivity of different pollinators to a different range of colours within the floral smorgasbord seems to be another example of conflict avoidance. Plants and animals both benefit from operating within a niche market.
As the insects and birds harvested sweet nectar from flowers shaped to suit them, they collected pollen on their bodies. When they visited other flowers of that species, pollen rubbed off on a female sex organ in enough cases to increase the reproduction rate above that from wind pollination.
Like other plants angiosperms still set more seeds than necessary, and some birds and animals still ate the excess.
Soon some plants were giving their seeds a protective coating so that they could lie dormant for longer, while others started growing nutrient-rich fruit around their seeds to provide ready-made fertilizer for the seed when it dropped and decayed. Some fruit became juicy and sweet when ripe, and even brightly coloured. And so its scent or hue attracted other birds and animals, which either discarded the seeds after eating the fruit or swallowed and excreted them somewhere else.
Meanwhile a few plants began to protect their seeds or leaves with toxins to discourage food-seekers, and a few animals were in turn developing a liver that filtered out the toxins. Today some fungi use not only poison to discourage potential consumers, but also bright colours like red – ignored at the forager’s peril.
All this interaction is based on protecting and passing on diverse ways of being alive, and communication within the system is an integral part of that.
(One example of Australian flower and animal coevolution is the nectar-flow of banksias and grevilleas in certain areas. It coincides with the breeding season of local honey-eating birds, with their specialised brush-tipped tongues. And it also triggers the breeding season of their predators: kookaburras, goannas and snakes.
(Honey-eating and fruit-eating mammals that feed at night, like possums and bats, are also part of these ecosystems. As today’s bush-regenerators in the Blue Mountains know only too well, in disturbed ecosystems some exotic plants also successfully co-opt native animals, particularly birds, in generating and spreading their offspring.)
The mechanism of an animal’s colour vision is an integral part of its way of living. Flower, fruit and insect harvesters need tg be able to distinguish colours, often including those in the ultra-violet part of the spectrum, while animals that feed on grass or meat have little or no such need.
The physics and chemistry involved in the actual production of colour, however, is much more complex.
As it is in Earth’s rocks and minerals, it seems to be basically a matter of a range of pigments, a process that started as we have seen with the green photosynthesizing pigment chlorophyll. But in birds like peacocks and flying insects like butterflies it is often a process of developing a series of reflective surfaces that scatter light into a range of colours.
Theories based on either random or creative evolution cannot yet explain how this emerged, or how the wonderful complexity of colour and light used by a range of animals in communication emerged. (A not-so-well-known example is seen in today’s cuttle-fish gathering to spawn off Australia’s south coast.)
Back in our story several flying insect families engaged in co-evolution with flower-bearing plants were by now undergoing a more drastic kind of metamorphosis - from a soft larval form through pupation into a very different adult form.
Their transformation within the pupa is very mysterious. The cells making up the larva break down into a genetic soup, from which adult cells gradually emerge, divide, multiply and differentiate.
A few biologists think that this is a remnant echo at the cellular level of an ancient battle, in which an early flying insect took over the body of a soft-bodied crawling insect. If this remarkable theory is true, it is yet another example of competition being transformed into joint effort.
Some of these insects were also creating distinctive social groups. Like dinosaurs and mammals they limited the number of offspring, and then spent a lot of time and energy looking after them - but they had an idiosyncratic way of doing it.
Their strategy was to clump lots of infertile females around a very fertile ‘queen-mother’, with a few males being specially produced just before her single mating-time.
The colony‘s members built a communal home around her eggs and helpless larvae and then formed separate nursery and defence cohorts, using chemical signals to communicate with each other in an instant. Most scientists describe such groups as operating like a complex organism because they work in such close co-ordination - like cells in a single being.
As anyone who has kept bee-hives knows, warrior bees in a hive that has lost its queen fight in wave after wave of suicide squads. And ant warriors are particularly aggressive in the first years of a colony, when they have many young to feed and only a few adults foraging for food.
Of course most metamorphosing insects did not develop societies. Today, like virtually all spiders, and like monotremes, they live alone but for a brief and dramatic mating. Some, like moths and butterflies, lay their eggs on a beautiful tasty leaf, from which the larvae crawl onto other leaves, eating and growing until their biological clock tells them to pupate. And some, like wasps, carefully prepare a burrow and lay their eggs inside in or on a ready-to-eat meal – either still alive or specially killed.
(Many Australian native bee species are also solitary – and stingless. We are only beginning to appreciate their uniqueness and diversity. Our iconic social insects are termites - either inspiring home-builders or devastating home-wreckers, depending on your point of view. They have also made themselves useful to people in northern Australia over thousands of years by hollowing out tree branches, which men then use to make a unique musical instrument – the didjeridoo.)
Today we see social bees, wasps and ants as the embodiment of vigorous protection of one’s territory against outsiders. Whether it emerged among them or not, territorial protection is an essential part of coevolution, limiting local population growth and thus reducing potential competition for resources, and also enabling the development of self-protection skills.
Most animal species today see protection of territory from outsiders and local competitors as a top priority whether they live in groups or have a solitary lifestyle. Plants are also territorial to different degrees. (In the Upper Blue Mountains the most notorious examples are noxious weeds like blackberries and montbretias.)
As we have seen with colour vision, the members of each species within an ecosystem perceive only a fraction of the total reality of their territory. They take in only what they need to know in order to have a chance of surviving and thriving. Since their most urgent needs relate to food and water, reproduction, and avoiding or escaping danger, they generally see the world through this frame of reference (whether instinctive or learned).
At this point in our story a flowering plant’s frame of reference for an insect was its hairy legs and wings (pollen-courier). A plant-eating dinosaur’s frame of reference for a tree was its tasty leaves (browser food). A dung beetle’s frame of reference for a dinosaur was its tasty warm dung (dung beetle food) and big feet (danger).
The point is that such frames of reference are absolutely functional - as long as there is no sudden change that threatens a whole eco-system’s survival.
But around 65 million years ago Earth’s Fifth Major Mass Extinction occurred. Tectonic movement had separated Africa and South America, pushed India north, almost split Australia and Antarctica and moved Africa’s northeastern corner closer to Eurasia. Now the Atlantic Ocean was widening, with the usual violent disturbances.
(New Zealand had also begun breaking away from Australia, warping its east coast, and pushing up the Great Dividing Range.)
Then an asteroid with a diameter of about 12 km hit Mexico on today’s Yucatan Peninsula (at the time under shallow water). It left a crater 170 km wide and ruptured into several huge segments that apparently flew into the air before returning to make further devastating impacts. Earthquakes and tsunamis occurred across the globe, along with acid rain, a global firestorm and a huge cloud of dust, which blocked out the Sun’s light and heat for many months.
In the following mass extinction ecosystems that had flourished for millions of years started to break down. Within a few thousand years 65% to 70% of species were made extinct, including many animals in the water and on land and virtually all those on land weighing more than 20 kilograms as adults. Among those that disappeared were the iconic ammonites and around 1,000 species of dinosaurs - an order of land-vertebrates that had been extremely successful for 160 million years.
Remember that this transformational change was due to a completely unexpected series of events, and thus beyond the capacity of most animal species to adapt. Earth’s environment may be largely supportive, but it can never be absolutely stable.
And yet many species of insects and also of some small birds and mammals managed to survive both the initial catastrophe and its long-term effects.
Perhaps this was the original stimulus for migration in birds. They would have had to fly long distances in search of isolated patches where the environment was not so hostile. We will come back to this in ‘Our Third Age’.
Meanwhile small mammals were no doubt helped by their ability to regulate their body temperature, together with their furry skins, burrowing skills and nocturnal lifestyle - as well as their practice of getting protein from a wide range of insects.
But from our point of view the main effect was the demise of large dinosaurs, because it cleared the way for a wider range of mammals, including us, to evolve in spectacular ways.
* * * * * *
(More Google images - click to enlarge)
(More Google images - click to enlarge)
2 comments:
Wow, that impact image is amazing. Thanks for a great story
Your blog keeps getting better and better! Your older articles are not as good as newer ones you have a lot more creativity and originality now keep it up!
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