Sex and the Single Kauri

Innovation in reproduction

cone 1
Araucariaceae was one of the first of the plant families to adopt a creative approach to sex, an innovation that would help the family spread far beyond the shores of Godwana. Sex for plants had been a slow and confused process for rather a long time before the sexually adventurous plants that predated Araucariaceae by 125 million years began their experiments. Proper reproduction for their forebears had involved two stages, one sexual, and one asexual. The sexual stage is called the gametophyte generation, from which springs a sporophyte generation that produces spores, which drift off to a new spot to produce a new gametophyte generation of moss-like plants that will sexually reproduce to form spore bearing offspring, which in turn make spores that produce more moss, ad infinitum. While effective, this system was not only cumbersome, it also required plenty of water to transport the spores and to initiate their moss growing process. This might have been fine in the swampy late Devonian period, but on Godwana the options for spore spreading reproduction were reduced.

So it was that first the cycads and seed bearing ferns emerged, and then, 100 million years later, the Ginkgos, each having evolved their own method of sexual reproduction that was not only more efficient and more robust, it was possibly more enjoyable if trees actually can enjoy what they do. At least it seems that way from a human perspective.

Seed bearing was a huge development for plants, as the security an embryo encased in a hard, protective shell gave it access to expanding in a diverse range of environments, not just the damp places where moss will grow. The shell encased embryo that is a seed grows and stores food while attached to its parent plant and as well as building a supply of energy acquires from its parent a set of chemical instructions that tell it when conditions are suitable for the embryo to become active, and to sprout and grow into a new, young plant. Protected by its hard shell, and fully self contained with all the mechanisms required to create a new, independent organism, these seeds gave the embryo plant the ability to travel the globe from their Gondwana origins, albeit that this often meant simply sticking with a particular bit of Gondwana as it drifted off to become part of a new continent. For those attached to future India, Africa or South America, staying still delivered considerable travel, and the possibility of long term survival, while for those rooted into the landmass that would become Antarctica, the future was decidedly chilly and relatively short.

The Araucariaceae took the seed making business a step further than that of the pioneering cycads, seed ferns and Ginkgos, evolving cones in which the seeds could grow, steadily accumulating the sustenance and protection that would maximise their chances of dispersing the seed so that a new generation would grow successfully. This process was so successful it was adopted by the whole family of trees we call Conifers, the cone bearers While these they have subsequently been superseded in number and range by flowering trees, the Angiosperms, Conifer whänau include both the largest and oldest living things on the planet, the North Americans – Californian Redwood and a Bristlecone Pine respectively. Bristlecones live in the sub alpine regions of the Western United States and can be up to 5000 years old, while the tallest Redwoods in Northern California make 110 metres.

Talking about sexual innovation, the Conifers are a liberal lot, and can cope with either, or both sexes on the one tree. Cones are emphatic things, they are either male or female, never both, and some Conifers have both sexes on them , while others make a speciality of one or the other. In the case of the family Araucariacea there are both male and female cones on each tree, with the male cones producing pollen that fertilises the female cones, either on the same tree, or more likely on a neighbouring one. Kauri, like all the Araucariaceae utilise the wind to consummate their relationships and to disperse the fertilised seed once it is ripe. The female cones will produce ripe seed around a year after they are pollinated., sending it out on the wind to fall where it may and with luck, germinate and grow into a new tree.
Araucariaceae was one of the first of the plant families to adopt a creative approach to sex, an innovation that would help the family spread far beyond the shores of Godwana. Sex for plants had been a slow and confused process for rather a long time before the sexually adventurous plants that predated Araucariaceae by 125 million years began their experiments. Proper reproduction for their forebears had involved two stages, one sexual, and one asexual. The sexual stage is called the gametophyte generation, from which springs a sporophyte generation that produces spores, which drift off to a new spot to produce a new gametophyte generation of moss-like plants that will sexually reproduce to form spore bearing offspring, which in turn make spores that produce more moss, ad infinitum. While effective, this system was not only cumbersome, it also required plenty of water to transport the spores and to initiate their moss growing process. This might have been fine in the swampy late Devonian period, but on Godwana the options for spore spreading reproduction were reduced.

So it was that first the cycads and seed bearing ferns emerged, and then, 100 million years later, the Ginkgos, each having evolved their own method of sexual reproduction that was not only more efficient and more robust, it was possibly more enjoyable if trees actually can enjoy what they do. At least it seems that way from a human perspective.

Seed bearing was a huge development for plants, as the security an embryo encased in a hard, protective shell gave it access to expanding in a diverse range of environments, not just the damp places where moss will grow. The shell encased embryo that is a seed grows and stores food while attached to its parent plant and as well as building a supply of energy acquires from its parent a set of chemical instructions that tell it when conditions are suitable for the embryo to become active, and to sprout and grow into a new, young plant. Protected by its hard shell, and fully self contained with all the mechanisms required to create a new, independent organism, these seeds gave the embryo plant the ability to travel the globe from their Gondwana origins, albeit that this often meant simply sticking with a particular bit of Gondwana as it drifted off to become part of a new continent. For those attached to future India, Africa or South America, staying still delivered considerable travel, and the possibility of long term survival, while for those rooted into the landmass that would become Antarctica, the future was decidedly chilly and relatively short.

The Araucariaceae took the seed making business a step further than that of the pioneering cycads, seed ferns and Ginkgos, evolving cones in which the seeds could grow, steadily accumulating the sustenance and protection that would maximise their chances of dispersing the seed so that a new generation would grow successfully. This process was so successful it was adopted by the whole family of trees we call Conifers, the cone bearers While these they have subsequently been superseded in number and range by flowering trees, the Angiosperms, Conifer whänau include both the largest and oldest living things on the planet, the North Americans – Californian Redwood and a Bristlecone Pine respectively. Bristlecones live in the sub alpine regions of the Western United States and can be up to 5000 years old, while the tallest Redwoods in Northern California make 110 metres.

Talking about sexual innovation, the Conifers are a liberal lot, and can cope with either, or both sexes on the one tree. Cones are emphatic things, they are either male or female, never both, and some Conifers have both sexes on them , while others make a speciality of one or the other. In the case of the family Araucariacea there are both male and female cones on each tree, with the male cones producing pollen that fertilises the female cones, either on the same tree, or more likely on a neighbouring one. Kauri, like all the Araucariaceae utilise the wind to consummate their relationships and to disperse the fertilised seed once it is ripe. The female cones will produce ripe seed around a year after they are pollinated., sending it out on the wind to fall where it may and with luck, germinate and grow into a new tree.