Dear Kitty. Some blog

From World Science:

Shedding light on the origin of flowers

May 17, 2006

Flowers are almost everywhere, but the origins of flowering plants are far from clear: Charles Darwin called the problem an “abominable mystery.”

A study of a plant seen as a “living fossil” now suggests flowers arose during a time of intense evolutionary experimentation, a researcher says.

The plant, found in the rain forests of New Caledonia in the South Pacific, has a unique way of forming eggs, said William “Ned” Friedman of the University of Colorado at Boulder, who conducted the study.

This quirk, he added, suggests the plant may be a missing link between the remarkably diverse flowering plants and their yet-to-be-identified extinct ancestors.

Flowering plants, called angiosperms, are thought to have evolved around 130 million years ago from gymnosperms, the prevailing land plants when dinosaurs reigned in the Cretaceous and Jurassic eras.

Angiosperms have become the dominant plants on Earth today.

The study involved Amborella trichopoda, a relic species descended from an ancient lineage.

Friedman analyzed the female part of its reproductive apparatus, called the embryo sac.

This sac has an extra sterile cell accompanying the egg cell compared with most modern flowering species, he found.

That’s “akin to finding a fossil amphibian with an extra leg,” according to a commentary published in the May 18 issue of the research journal Nature, where Friedman’s study also appeared.

“We associate this structure with a relatively primitive reproductive process,” Friedman added.

The peculiar egg-forming structure, he suggested, may eventually link the odd South Pacific shrub to gymnosperms such as conifers—cone-bearing trees such as pines, firs and junipers.

The finding suggests flowering plants may have arisen during a time when plant evolution was “particularly flexible,” Friedman proposed. That may have allowed for the evolution of the seemingly costly business of making flowers.

See also here.

Evolution of flowering plants: here.

Rare American chestnut trees found: here.

Very old Australian microbe fossils: here.

Parakeets of New Caledonia: here.

Birds of New Caledonia: here.

Caledonian crows and tool use: here.

Fossil conifers: Based on the newly discovered fossil specimens from 52 and 47 million years ago, Wilf and colleagues reassigned the fossil species to Papuacedrus, under the new name combination Papuacedrus prechilensi: here.